Статті в журналах: "Signaux radioactives"

1

Han, Yongchao, Shoulong Xu, and Youjun Huang. "Real-Time Monitoring Method for Radioactive Substances Using Monolithic Active Pixel Sensors (MAPS)." Sensors 22, no. 10 (May 22, 2022): 3919. http://dx.doi.org/10.3390/s22103919.

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This study presents a real-time monitoring technique for radioactive substances that meets safety management needs. We studied the accumulation characteristics of radiation response signals of monolithic active pixel sensors (MAPSs) based on their response and discrimination ability to gamma (γ) photon or neutron radiation. The radiation status of the radioactive substances was determined by monitoring the accumulation data of radiation responses. As per the results, Am-Be and 252Cf radiation response signals are primarily concentrated in the range of 0–70 pixels. Response signals of 60Co and 137Cs γ-ray were concentrated in two regions; there was a peak in the region with a pixel value of less than 50, and a plateau in the region with a pixel value of more than 75. Therefore, the results are able to discriminate between spectra. Furthermore, we designed a radioactivity monitoring system that is able to examine multiple radioactive materials. Its working principle is that a change in the accumulation of radioactivity monitoring data indicates a radiation change during the last accumulation cycle. This study provides vital technical support for the long-term supervision of radioactive substances.

2

Durrant, I. "Radioactive and Non-Radioactive In Situ Hybridization Techniques." Proceedings, annual meeting, Electron Microscopy Society of America 54 (August 11, 1996): 8–9. http://dx.doi.org/10.1017/s0424820100162508.

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In situ hybridization is a powerful technique that has found multiple applications in the biological sciences. The most widely used technique is in the analysis of mRNA species in cell populations. This is particularly useful for the analysis of relative amounts, site of transcription, timing and induction of transcription. Recent advances have lead the technique into the areas of relative quantification, dual signal detection and disease diagnosis. DNA targets can also be visualised by in situ hybridization both in cells and tissues and on isolated chromosomes and nuclei. There are a variety of systems that can be used to detect hybridization signals in situ. These choices are based in two areas, probe type and label type and this selection process holds true for both radioactive and non-radioactive systems.Probe selection is important and plays a part in the overall success of the application (see Table 1). RNA probes and oligonucleotide probes are the most widely used in cells and tissues whereas DNA probes are routinely used for chromosome and nuclei targets. RNA probes are used due to the higher sensitivity obtained but oligonucleotide probes are gaining in popularity due to ease of use. The lower sensitivity seen with these probes, due to lower labelling capacity, can be overcome by use of probe cocktails.

3

Guyette, Frank, Joe Suyama, Jerry Rosen, and Michael Allswede. "Prevalence of Radioactive Signals from Surveillance of an Emergency Department." Prehospital and Disaster Medicine 21, no. 4 (August 2006): 276–81. http://dx.doi.org/10.1017/s1049023x00003836.

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AbstractIntroduction:Since the 11 September 2001 terrorist attacks in the United States, concerns have been raised regarding the threat of a radiological terrorist weapon. Although the probability of the employment of a nuclear device is remote, the potential of a radiological dispersal device (RDD) or “dirty bomb” is of concern. While it is unlikely that such a device would produce massive numbers of casualties, it is far more likely that it would result in pub- lic panic and perhaps even disable the local healthcare system. The utility of surveillance with radiation detectors in the healthcare setting has not been fully evaluated.Objective:The objective of this study was to characterize the prevalence of radioactive sources entering an urban emergency department (ED).Methods:A retrospective review of data obtained from a radiation detector positioned to detect radioactive people entering an ED of an urban academic hospital that serves 45,000 patients/year was performed. Graphical outputs of radioactivity were recorded in Microsoft ExcelTM (Microsoft, Redmond, WA, US) spreadsheets in microREM/hour. Data were collected continuous-ly from 22 December 2003 to 22 January 2004. An event was defined as any elevation in radiation levels >95% confidence interval from the mean level of background radiation over 72 hours (h).Results:A total of 215 events were observed over a 28-day period, with a mean value of 7.7 events/day, and a maximum of 15 events/day. During the 28-day period, the baseline mean level of background radiation was 2–4 microREM/h. Readings ranged from 2,148.28–17,292.25 microREM/h with a maximum sustained detector exposure of 684.37 microREM. Distinct signal patterns were seen at both detectors including tonic, phasic, dual, and short duration spikes.Conclusion:The number of radioactive signals detected from persons entering the ED was much higher than expected. While the vast majority of these signals pose no health threat, they may make routine screening for a radiological terrorist event difficult.Further study is needed to determine this correlation.

4

Min, Sujung, Kwang-Hoon Ko, Bumkyung Seo, JaeHak Cheong, Changhyun Roh, and Sangbum Hong. "Wireless Backpack System for Detection of Radioactive Cesium on Contaminated Soil Using Portable Plastic Scintillator with Efficient Readout Device." Electronics 10, no. 22 (November 18, 2021): 2833. http://dx.doi.org/10.3390/electronics10222833.

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The miniaturization and usability of radiation detectors make it increasingly possible to use mobile instruments to detect and monitor gamma radiations. Here, a Bluetooth-based mobile detection system for integrated interaction in a backpack was designed and implemented to smart equipment for the detection of radioactive cesium on contaminated soil. The radiation measurement system was demonstrated in the form of a backpack using a quantum dot (QD)-loaded plastic scintillator manufactured and prepared directly in this study, and it can be measured by a person in the wireless framework of integrated interaction. The QD-loaded plastic scintillator was measured after setting the distance from the contaminated soil to 20, 50, and 100 mm. As a result, the detection efficiency of the commercial plastic scintillator (EJ-200) was calculated to be 11.81% and that of the QD-loaded plastic scintillator was 15.22%, which proved the higher detection efficiency performance than the commercial plastic scintillator. The measurement result was transmitted to a personal computer using Bluetooth as a portable system. In the future, this wireless system design could be expanded as a wireless communication system equipped with a global positioning system to detect and measure radioactively contaminated environments.

5

Zhang, Lei, Chenkai Qiao, Jingjun Zhu, Yu Liu, Yulu Yan, Shin-Ted Lin, Shukui Liu, Changjian Tang, and Haoyang Xing. "Preparation of Large Volume Solid Argon Crystal and Its Feasibility Test as a Scintillation Material." Crystals 12, no. 10 (October 7, 2022): 1416. http://dx.doi.org/10.3390/cryst12101416.

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An important background to the liquid argon detectors is that they are caused by the diffusion of radioactive isotopes in a scintillator (liquid phase). This radioactive isotope is produced in argon’s surrounding devices, such as circulation pipelines and liquid argon containers. The solid argon as a scintillation material in the detector can inhibit the diffusion and drift of radioactive isotopes in a solid phase scintillator. Additionally, the structure of a solid argon detector is simple and reduces the total source of radioactive background. In the CDEX-300 detection system, solid argon could substitute for liquid argon as the veto detector, preventing radioactive isotopes drifting to the central main detector (HPGe detectors array) surface to reduce backgrounds. Therefore, solid argon has great potential in the experiments since it is especially helpful to get the lower background in a larger active volume than liquid argon required in those low background detection experiments. This work introduces the preparation process and device of the large volume transparent crystalline argon, the acquisition of scintillation light, and the pulse amplitude spectrum of 137Cs obtained from a prototype detector of transparent solid argon crystal. The results show that the scheme proposed in this study can successfully produce a large volume transparent crystalline argon detector, the scintillation light signals can be effectively obtained from the solid argon scintillator, and the corresponding pulse amplitude spectrum is given. This work indicates that it is feasible to develop a solid argon crystal scintillation detector by using our approach.

6

Babińska, Joanna, Krystyna Dyrek, and Piotr Wyszomirski. "EPR Study of Paramagnetic Defects in Clay Minerals." Mineralogia 38, no. 2 (January 1, 2007): 125–38. http://dx.doi.org/10.2478/v10002-007-0021-x.

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EPR Study of Paramagnetic Defects in Clay MineralsRadiation induced defects (RID-s) and transition metal ion impurities were revealed by EPR (Electron Paramagnetic Resonance) spectroscopy in kaolinites from a number of Polish deposits. Arelationship between the intensity of the EPR signals of the RID-s and quantity of radioactive elements was defined in these minerals. In one of the deposits of kaolinites (Wyszonowice) the EPR signal intensity depends on grain size. Other clay minerals studied (illites, montmorillonites) only show weak signals of the RID type.

7

Arakelyan, N. V., and Yu A. Kutoyants. "ON THE IDENTIFICATION OF THE SOURCE OF EMISSION ON THE PLANE." Proceedings of the YSU A: Physical and Mathematical Sciences 53, no. 2 (249) (August 15, 2019): 75–81. http://dx.doi.org/10.46991/pysu:a/2019.53.2.075.

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We consider the problem of identification of the position and the moment of the beginning of a radioactive source emission on the plane. The acts of emission constitute inhomogeneous Poisson processes and are registered by $ K $ detectors on the plane. We suppose that the moments of arriving of the signals at the detectors are measured with some small errors. Then, using these estimate, we construct the estimators of the position of source and the moment of the beginning of emission. We study the asymptotic properties of these estimators for large signals and prove their consistency.

8

Wulandari, H., F. Von Feilitzsch, M. Huber, Th Jagemann, J. Jochum, T. Lachenmaier, J. C. Lanfranchi, et al. "Study on Neutron-induced Background in the CRESST Experiment." Symposium - International Astronomical Union 220 (2004): 491–92. http://dx.doi.org/10.1017/s0074180900183895.

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CRESST II is an experiment for direct WIMP search, using cryogenic detectors. the ratio of the two signals (temperature rise and scintillation light) measured for each interaction is an excellent parameter for discrimination of the radioactive background. the main remaining background is the neutron flux present at the experimental site, since neutrons produce the same signals as WIMPs do. Based on Monte Carlo simulations the present work shows how neutrons from different origins affect CRESST and which measures have to be taken into account to reach the sensitivity goal.

9

KOUMANOV, Françoise, Jing YANG, E. Alison JONES, Yasumaru HATANAKA, and D. Geoffrey HOLMAN. "Cell-surface biotinylation of GLUT4 using bis-mannose photolabels." Biochemical Journal 330, no. 3 (March 15, 1998): 1209–15. http://dx.doi.org/10.1042/bj3301209.

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New cell-impermeant bis-mannose photolabels have been developed with biotinyl groups attached to 4-(1-azi-2,2,2-trifluoroethyl)-benzoyl-1,3-bis(d-mannos-4-yloxy)-2-propylamine (ATB-BMPA) by either a polyethoxy spacer (Bio-ATB-BMPA) or an additional hexanoic acid spacer (Bio-LC-ATB-BMPA). The half-maximal inhibition constants, Ki values, for inhibition of glucose transport activity in insulin-stimulated rat adipocytes were determined to be 359±10 and 273±28 μM for Bio-ATB-BMPA and Bio-LC-ATB-BMPA, respectively. These values are similar to those previously reported for the non-biotinylated compound ATB-BMPA. Following UV-irradiation-induced cross-linking of the biotinylated photolabels to rat adipocytes, the biotinylated glucose transporter isoform 4 (GLUT4) could be detected by non-radioactive and radioactive methods that utilized the interaction with streptavidin. Biotinylated GLUT4 from 1-2 μg of adipose cell membranes, precipitated onto magnetic streptavidin beads, could be sensitively and quantitatively detected using an electrochemiluminescent assay method. This utilized a ruthenium-tagged anti-GLUT4 antibody that on excitation at an electrode generated an electrochemiluminescent signal in an ORIGEN analyser. Alternatively, surface-biotinylated GLUT4 could be easily, but less sensitively, detected in streptavidin agarose precipitates which were analysed by conventional GLUT4 Western blotting. Data obtained using the non-radioactive methods compared favourably with those using tritiated versions of the biotinylated probes. Insulin treatment of adipocytes increased the levels of signals from surface biotinylated GLUT4 by ~ 10-fold or ~ 20-fold, respectively, when the electrochemiluminescent or the Western blot detection methods were used and these signals were blocked by cytochalasin B.

10

Steinitz, G., M. C. Martín, N. Gazit-Yaari, M. L. Quesada, J. de la Nuez, R. Casillas, U. Malik, and Z. B. Begin. "Multi-day radon signals with a radioactive decay limb—Occurrence and geophysical significance." Applied Radiation and Isotopes 64, no. 4 (April 2006): 520–24. http://dx.doi.org/10.1016/j.apradiso.2005.10.004.

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11

Gottlieb, Ore, and Abraham Loeb. "Electromagnetic signals from the decay of free neutrons in the first hours of neutron star mergers." Monthly Notices of the Royal Astronomical Society 493, no. 2 (February 7, 2020): 1753–60. http://dx.doi.org/10.1093/mnras/staa363.

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ABSTRACT The first hours following a neutron star merger are considered to provide several ultraviolet (UV)/optical/near-infrared signals: β-decay emission from free neutrons, radioactive decay of shocked heavy elements in the cocoon and cocoon’s cooling emission. Here, we consider two additional emission sources: β-decay of free neutrons in the cocoon and synchrotron by the β-decay electrons. We present three-dimensional relativistic hydrodynamic simulations of jets that propagate in a multi-layer ejecta from the merger and calculate semi-analytically the resulting light curves. We find that the free neutrons emission at high latitudes is enhanced by the cocoon by a factor of a few to power a wide (≲60°) and brief (∼1 h) UV signal that can reach an absolute magnitude of ≳−15, comparable with the cooling emission. If the ejected neutron matter mass is $M_{\rm n} \gtrsim 10^{-4}\, {\rm M_{\odot }}$, the synchrotron emission may yield a long (∼8 h) quasi-isotropic UV/optical signal with an absolute magnitude between −12 and −15, depending on the magnetic field. Such a high mass of a mildly relativistic component may partly obscure the cocoon’s shocked r-process elements, thereby attenuating its radioactive decay emission. Future observations on these time-scales, including null detections, may place constraints on the ejected neutron matter mass and shed light on the ejecta and jet-cocoon characteristics.

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Liu, Yantao, Lei Shuai, Daowu Li, Shuangquan Liu, Yingjie Wang, Wei Zhou, Huan Huang, et al. "High-sensitivity stereo coded aperture gamma camera for three-dimensional localization of radioactive hotspots." AIP Advances 12, no. 8 (August 1, 2022): 085317. http://dx.doi.org/10.1063/5.0096865.

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This work presents a novel stereo coded aperture gamma camera based on four detection modules placed within four quadrants. Each module includes 48 × 48 strips of Bi4Ge3O12 scintillators, 24 × 24 pieces of silicon photomultipliers (SiPMs), and a set of data acquisition circuits. All signals from the SiPMs are individually extracted and finally simplified into 144 outputs to calculate the positions and energies of gamma-rays. Two masks of modified uniformly redundant arrays are fixed in the front of the top-right and bottom-left modules and two anti-masks are fixed in the top-left and bottom-right modules to achieve simultaneous imaging without dual measure. Once the projections of radioactive sources are determined, their source-to-detector distances can be estimated by our new multocular ranging algorithm. A series of lab and field experiments, including flood histogram and energy spectrum testing, field-of-view and angular resolution testing, real-time imaging, long-distance imaging, and ranging ability testing, with different radioactive sources, such as 137Cs, 22Na, 241Am, 60Co, 133Ba, and 75Se, have been completed to evaluate the comprehensive ability of the stereo gamma camera. The results show that the stereo gamma camera has a strong ability for the three-dimensional localization of radioactive sources over long distances with a high image sensitivity. So far, the stereo gamma camera has been successfully used in practical nuclear security and safety tasks although the angular resolution and the ranging algorithm robustness should be more optimized in the future.

13

Tomoda, T., M. Arimoto, T. Mizuno, D. Sato, F. Lucyana, J. Kataoka, M. Kato, et al. "Multi-pixel photon counter-based gamma camera with pinhole collimator to locate Cs-137 sources at high dose rates for the Fukushima nuclear power plant." Journal of Instrumentation 19, no. 02 (February 1, 2024): C02032. http://dx.doi.org/10.1088/1748-0221/19/02/c02032.

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Abstract The Fukushima Daiichi Nuclear Power Plant was severely damaged during the 2011 Great East Japan Earthquake. However, the ongoing decommissioning work has been limited by the complexity of the reactor's internal structure and very high radiation levels; locating radioactive sources is essential for efficient decommissioning. Conventional gamma cameras are mainly designed for low radiation dose (∼mSv/h) and using them under high radiation conditions is difficult (>Sv/h). Therefore, we developed a pinhole gamma camera with a gamma radiation detector consisting of a high-speed YGAG scintillator array and multi-pixel photon counters to locate radioactive sources at high dose rates. The gamma-ray photon signals captured by the developed two-dimensional detector array can be processed at a speed as high as >1 MHz/pixel using the developed large scale integrated circuit. Herein, we report the measurement results of an extremely high radioactivity of 137Cs (∼34 TBq) using the developed gamma camera. The gamma-ray source position was determined using an angular size of ∼4.6°, with images obtained at 2 m from the radioactive source and at a dose rate of 0.3 Sv/h. The direct gamma rays with a photoelectric peak at 662 keV and scattered component of gamma rays can be distinguished from the measured spectrum. We also characterize the imaging capability of the 137Cs depending on the detected gamma-ray energies and discuss related details.

14

Hanus, Robert, Marcin Zych, Barbara Wilk, Marek Jaszczur, and Dariusz Świsulski. "Signals features extraction in radioisotope liquid-gas flow measurements using wavelet analysis." EPJ Web of Conferences 213 (2019): 02023. http://dx.doi.org/10.1051/epjconf/201921302023.

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Knowledge of the structure of a flow is significant for the proper conduct of a number of industrial processes. In this case, a description of a two-phase flow regimes is possible by use of the time-series analysis in time, frequency and state-space domain. In this article the Discrete Wavelet Transform (DWT) is applied for analysis of signals obtained for water-air flow using gamma ray absorption. The presented method was illustrated by use data collected in experiments carried out on the laboratory hydraulic installation with a horizontal pipe, equipped with two Am-241 radioactive sources and scintillation probes with NaI(Tl) crystals. Signals obtained from detectors for slug, plug, bubble, and transitional plug – bubble flows were considered in this work. The recorded raw signals were analyzed and wavelet energy was extracted using multiresolution analysis. It was found that energies of wavelet approximation at 1-5 levels are useful to recognize the structure of the flow.

15

Miramonti, Lino. "Low background techniques in liquid scintillator detectors." International Journal of Modern Physics A 32, no. 30 (October 30, 2017): 1743010. http://dx.doi.org/10.1142/s0217751x17430102.

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Many neutrino physics experiments use organic liquid scintillators, which present a unique advantage: enormous masses (in the order of tens ktons) with very low radioactive background can be reached by assembling a detector with organic liquid scintillators. Thanks to the very fast decay rate, it is possible to localize the event in space and time and discriminate it from the background signals. Furthermore, organic liquid scintillators are very efficient in alfa/beta discrimination and offer the possibility to dissolve solvents in the chemical compounds to enhance the signal.

16

Lingenfelter, Daniel J., Jeffrey A. Fessler, Clayton D. Scott, and Zhong He. "Benefits of Position-Sensitive Detectors for Radioactive Source Detection." IEEE Transactions on Signal Processing 58, no. 9 (September 2010): 4473–83. http://dx.doi.org/10.1109/tsp.2010.2051805.

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17

Wolff, E. W. "Signals of atmospheric pollution in polar snow and ice." Antarctic Science 2, no. 3 (September 1990): 189–205. http://dx.doi.org/10.1017/s095410209000027x.

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In their upper layers, the polar ice sheets contain a detailed record of changes in the atmosphere over the industrial period. Measurements from air bubbles in ice have shown that the CO2 content of the atmosphere has increased by 25% in the last 200 years, and that of CH4 has more than doubled. Ice core records have demonstrated a close correspondence between greenhouse gases and temperature during the last glacial cycle. Profiles of radioactive species in snow clearly document nuclear bomb tests in the atmosphere, and the recent Chernobyl accident has also left a signal in Northern Hemisphere ice. Nitrate has more than doubled in Greenland snow over the industrial period, while sulphate has more than trebled. No significant trend is seen in Antarctic snow for these anions. Pb increased 100-fold until the 1970s in Greenland snow, but concentrations appear now to be declining. A small increase is also recorded in Antarctic snow. Organochlorine compounds offer great potential for pollution studies in snow. The ability to study global scale pollution in polar ice could be hampered if there is significant local pollution. In Antarctica, impact on the atmosphere from local human activities is still mainly confined to small areas near stations.

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Baidoo-Williams, Henry E., Soura Dasgupta, Raghuraman Mudumbai, and Erwei Bai. "On the Gradient Descent Localization of Radioactive Sources." IEEE Signal Processing Letters 20, no. 11 (November 2013): 1046–49. http://dx.doi.org/10.1109/lsp.2013.2279499.

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19

Henríquez, Felipe, Luis Maldonado, Juan Yianatos, Paulina Vallejos, Francisco Díaz, and Luis Vinnett. "The Use of Radioactive Tracers to Detect and Correct Feed Flowrate Imbalances in Parallel Flotation Banks." J 5, no. 2 (June 12, 2022): 287–97. http://dx.doi.org/10.3390/j5020020.

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This work presents the application of radioactive tracers to detect and correct feed flowrate imbalances in parallel rougher flotation banks. Several surveys were conducted at Minera Los Pelambres concentrator, in banks consisting of 250 m3 mechanical flotation cells. The feed pulp distribution was estimated from the mean residence times, which were obtained from residence time distribution measurements. The tracer was injected in the feed distributor and the inlet and outlet tracer signals of cells 1 and 2 were measured by on-stream sensors. The baseline condition for the pulp distribution was defined by the valve settings in the feed distributor, which led to an unbalanced condition for two parallel rougher banks, with 34% of the pulp being fed to bank A and 66% to bank B. New valve configurations were evaluated, with a fraction of the feed being directed to the rougher bank C, which was not initially fed from the same distributor. The feed distribution was finally balanced with 49% of the pulp being fed to bank A versus 51% to bank B. Thus, the radioactive traces proved to be a powerful tool to industrially detect and improve feed distributions in parallel flotation circuits.

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Gorshkov, Nikolay Ivanovich, Andrei Yur'evich Murko, Yulia Igorevna Zolotova, Olga Vladimirovna Nazarova, Valerii Dmitrievich Krasikov, Sergei Vasilievich Shatik, and Evgenii Fedorovich Panarin. "Introduction of Re(CO)3+/99mTc(CO)3+ Organometallic Species into Vinylpyrrolidone-Allyliminodiacetate Copolymers." Polymers 13, no. 11 (June 1, 2021): 1832. http://dx.doi.org/10.3390/polym13111832.

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N-vinylpyrrolidone-co-allylamine copolymers (VP-co-AA) containing iminodiacetic (IDA) chelation units were prepared in the range of molecular masses of the copolymers from 9000 to 30,000 Da depending on polymerization conditions. Non-radioactive organometallic species Re(CO)3+ were introduced into polymeric carriers under mild conditions; the prepared metal–polymeric complexes were characterized by IR, NMR, ESI-MS and HPLC. IR spectra data confirmed the coordination of M(CO)3+ moiety to the polymeric backbone via IDA chelation unit (appearance of characteristic fac-M(CO)3+ vibrations (2005, 1890 cm−1), as well as the appearance of group of signals in 1H NMR spectra, corresponding to those inequivalent to methylene protons CH2COO (dd, 4.2 ppm), coordinated to metal ions. The optimal conditions for labeling the PVP-co-AA-IDA copolymers with radioactive 99mTc(CO)3+ species were determined. The radiochemical yields reached 97%. The obtained radiolabeled polymers were stable in blood serum for 3 h. In vivo distribution experiments in intact animals showed the high primary accumulation of technetium-99m MPC (MM = 15,000 Da) in blood with subsequent excretion via the urinary tract.

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Berndt, Alexander, Hartwig Kosmehl, Dino Celeda, and Detlef Katenkamp. "Reduced formamide content and hybridization temperature results in increased non-radioactive mRNA in situ hybridization signals." Acta Histochemica 98, no. 1 (January 1996): 79–87. http://dx.doi.org/10.1016/s0065-1281(96)80053-5.

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22

Alhamd, M. W., Sadeq Naeem Atiyah, Firas Taqi Almusawi, and Mazen Katea Al-Gharrawy. "Gamma Ray Spectrum by Software Methods for Radioactive Waste." Iraqi Journal of Industrial Research 10, no. 3 (December 14, 2023): 41–46. http://dx.doi.org/10.53523/ijoirvol10i3id323.

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The requirements of NTD (Neglected Tropical Diseases) and technological regulations for the operation of NPP (Nuclear Power Plant) power units (NP-001-97 (OPB-88/97), NP-082-07) define the requirements for monitoring the specific activity of iodine-131 (the amount of iodine) in the NPP primary circuit coolants. The advantages of laboratory control include accuracy of measurement and the radionuclide composition of the primary coolant, measured using high-precision laboratory equipment. Instrumental spectra were obtained for the detection units BDKG-205m with various options for the placement of waste in a container, their composition, mass of waste, average density, and various activity levels of waste. The basic idea behind gamma-ray spectroscopy is to detect and analyze the energy of incident gamma rays. Gamma rays of varying energy and intensity are emitted from radioactive sources. The gamma-ray energy spectrum is produced when gamma rays are detected and examined using a spectroscopy instrument. The initial stage in gamma-ray spectroscopy is to detect gamma rays using a suitable detector. The detector captures and measures the energy of incoming gamma rays. Scintillation detectors, semiconductor detectors, and gas-filled detectors are among the detectors used in gamma-ray spectroscopy. The incoming gamma-ray energy is converted into electrical signals that can be processed and studied by these detectors. The spectroscopic system measures and records the energy of gamma rays when they are detected. The derived energy spectrum depicts the intensity distribution of gamma rays as a function of energy. The spectrum is a visual representation of the different energy levels found in gamma-ray emission.

23

Hanus, Robert, Marcin Zych, Marek Jaszczur, Leszek Petryka, and Dariusz Świsulski. "Radioisotope measurements of the liquid-gas flow in the horizontal pipeline using phase method." EPJ Web of Conferences 180 (2018): 02032. http://dx.doi.org/10.1051/epjconf/201818002032.

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The paper presents application of the gamma-absorption method to a two-phase liquid-gas flow investigation in a horizontal pipeline. The water-air mixture was examined by a set of two Am-241 radioactive sources and two NaI(Tl) scintillation probes. For analysis of the electrical signals obtained from detectors the cross-spectral density function (CSDF) was applied. Results of the gas phase average velocity measurements for CSDF were compared with results obtained by application of the classical cross-correlation function (CCF). It was found that the combined uncertainties of the gas-phase velocity in the presented experiments did not exceed 1.6% for CSDF method and 5.5% for CCF.

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Pan, Bolin, Paul K. Marsden, and Andrew J. Reader. "Dual-Tracer PET Image Separation by Deep Learning: A Simulation Study." Applied Sciences 13, no. 7 (March 23, 2023): 4089. http://dx.doi.org/10.3390/app13074089.

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Multiplexed positron emission tomography (PET) imaging provides perfectly registered simultaneous functional and molecular imaging of more than one biomarker. However, the separation of the multiplexed PET signals within a single PET scan is challenging due to the fact that all PET tracers emit positrons, which, after annihilating with a nearby electron, give rise to 511 keV photon pairs that are detected in coincidence. Compartment modelling can separate single-tracer PET signals from multiplexed signals based on the differences in bio-distribution kinetics and radioactive decay. However, the compartment-modelling-based method requires staggered injections and assumes that each tracer’s input function is known. In this paper, we propose a deep-learning-based method to simultaneously separate dual-tracer PET signals without explicitly knowing the input functions. We evaluate the proposed deep-learning-based separation method on dual-tracer [18F]FDG and [11C]MET PET simulations and compare its separation performance to that of the compartment-modelling-based method, assessing performance dependence on the time interval between tracer injections as well as on the amount of training data. It is shown that the proposed method implicitly denoises the separated images and offers reduced variance in the separated images compared to compartment modelling.

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Bauswein, A., S. Goriely, and H. T. Janka. "SYSTEMATICS OF DYNAMICAL MASS EJECTION, NUCLEOSYNTHESIS, AND RADIOACTIVELY POWERED ELECTROMAGNETIC SIGNALS FROM NEUTRON-STAR MERGERS." Astrophysical Journal 773, no. 1 (July 29, 2013): 78. http://dx.doi.org/10.1088/0004-637x/773/1/78.

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26

Farinelli, R., I. Balossino, G. Bencivenni, G. Cibinetto, G. Felici, S. Fiore, I. Garzia, et al. "µRANIA-V: an innovative solution for neutron detection in homeland security." EPJ Web of Conferences 253 (2021): 07009. http://dx.doi.org/10.1051/epjconf/202125307009.

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Detection of neutrons is becoming of the utmost importance, especially in the studies of radioactive waste and in homeland security applications. The crisis of 3He availability has required the development of innovative techniques. One solution is to develop light gas detectors for neutron counting to be used as portals for ports and airports. The neutron is converted on the Boron-coated cathode, releasing a charged particle, whose passage can be identified by the gas detector. While several technologies have been deployed in the past, the project μRANIA-V (μRwell Advanced Neutron Identification Apparatus) aims to detect thermal neutrons by means of the μRwell technology, an innovative gas detector. The goal is to produce tiles to operate as portals in homeland security or for radioactive waste management. The technological transfer towards the industry has started, thus the production can be cost-effective also owing to a construction process relatively easier compared to similar apparatus. By reading directly the signals from the amplification stage, the neutrons can be counted with simplified electronics further reducing the total cost. In this paper, the project will be described, with details on the μRwell technology and on the neutron counting, on the test beam performed, and on the future plans.

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Peiffer, P., T. Pollmann, S. Schönert, A. Smolnikov, and S. Vasiliev. "Pulse shape analysis of scintillation signals from pure and xenon-doped liquid argon for radioactive background identification." Journal of Instrumentation 3, no. 08 (August 27, 2008): P08007. http://dx.doi.org/10.1088/1748-0221/3/08/p08007.

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28

Swanson, John-David, John E. Carlson, and Mark J. Guiltinan. "Use of image analysis software as a tool to visualize non-radioactive signals in plantin situ analysis." Plant Molecular Biology Reporter 24, no. 1 (March 2006): 105. http://dx.doi.org/10.1007/bf02914051.

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29

Wen, Chenglong, Yiqian Li, and Guanghai Feng. "Investigate cosmic rays: Analysis of the air showers." Journal of Physics: Conference Series 2724, no. 1 (March 1, 2024): 012052. http://dx.doi.org/10.1088/1742-6596/2724/1/012052.

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Abstract In this lab report, the concept of cosmic rays and their components that can be detected on the earth’s surface is introduced. In this experiment, four CosmicWatch muon detectors were used to detect the components of cosmic rays. This report describes the setup of the experiment as well as the method and algorithms used to filter the true signals of cosmic rays out of the background radioactive noises. Some process of the algorithm is visualized using histograms. The rate of air showers was found to be 0.151 mHz ± 0.022 mHz for a separation of 6.73 cm ± 0.08 cm, and 0.096 mHz ± 0.015 mHz for a separation of 13.5 cm ± 0.1 cm. Other sources of uncertainties are also analyzed in this report.

30

Hennig, W., Hui Tan, W. K. Warburton, and J. I. McIntyre. "Single-channel beta-gamma coincidence detection of radioactive xenon using digital pulse shape analysis of phoswich detector signals." IEEE Transactions on Nuclear Science 53, no. 2 (April 2006): 620–24. http://dx.doi.org/10.1109/tns.2006.870447.

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31

CAÑAMÓN, I., F. J. ELORZA, A. MANGIN, P. L. MARTÍN, and R. RODRÍGUEZ. "WAVELETS AND STATISTICAL TECHNIQUES FOR DATA ANALYSIS IN A MOCK-UP HIGH-LEVEL WASTE STORAGE EXPERIMENT." International Journal of Wavelets, Multiresolution and Information Processing 02, no. 04 (December 2004): 351–70. http://dx.doi.org/10.1142/s0219691304000585.

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This work analyzes the physical processes occurring in the Mock-up test of the FEBEX I and II projects. FEBEX I and II is an European research project (1996–2004) led by ENRESA, that has financial support from the European Commission. This experiment is based in two large-scale heating tests ("in-situ" test and "Mock-up" test) simulating a radioactive waste repository, and tries to analyze the thermo-hydro-mechanical (THM) processes that could eventually happen in this kind of repositories.The main objectives of this study have been the following: to identify the physical processes occurring in the Mock-up experiment and to characterize them quantitatively; to understand the nature and consequences of several incidents happening in the Mock-up during the heating phase; and, finally, to analyze the data reliability of the sensors measurements and to predict possible failures.The analysis techniques used in this work are both statistical (time series correlation and spectral analysis, wavelets analysis, matching pursuit analysis) and non-statistical (spatial distribution analysis of data). These methods aim to establish the existing relationships between several data series registered in the experiment, corresponding to the measured parameters, and to characterize on time and frequency the non-stationary response of the series. A better understanding of the main THM processes affecting the engineered barriers used for the isolation of the radioactive waste is then available with the results obtained from those analyses.

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Steinitz, G., P. Kotlarsky, and O. Piatibratova. "Indications for influence of artificial (man-made) activity on radon signals, in simulation experiments." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 472, no. 2195 (November 2016): 20160311. http://dx.doi.org/10.1098/rspa.2016.0311.

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Radon (Rn-222; a radioactive noble gas) is characterized by large temporal variations that differ significantly from variations of (i) other trace elements in geogas (noble gases); (ii) variation patterns of other dynamic geophysical systems (atmospheric, tidal). Consensus exists that there is no simple and straightforward understanding of the phenomena and its behaviour. This lacuna in the understanding of the underlying principles hampers the development of applications—such as radon as a proxy of processes in the seismogenic context. Using results from field investigations and simulation experiments the GSI suggested that an unidentified extraterrestrial component, probably in solar radiation, drives periodic radon signals in the diurnal and annual frequency bands. Recent findings from experimental investigations shed additional perspectives allowing a new evaluation of the issue. Particular transient signals, measured with alpha and gamma detectors, are interpreted to reflect the influence of artificial activity. Criteria are (i) signals lasting several hours that occur around midday on workdays (Sunday–Thursday); (ii) signals composed of a train of around 10 strong pulses, each lasting less than 15 min, occurring within several hours once a week, from Wednesday afternoon/evening to Thursday morning. A first interpretation is that an unidentified artificial activity of some sort (industrial?) generates and emits an unidentified agent that reaches enhanced confined mode experiments at the GSI laboratory, which respond to the incoming agent in the form of radon signals. Developing the capability of identification of such an earth-bound source generating an influencing agent is a key step towards understanding of external influence on radioactivity of radon.

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Guo, Donghao, Jingjing Wang, Huanqing Liu, Yuxi Bai, Yongcheng Li, and Weihao Liu. "Multiplicative Improved Coherence Factor Delay Multiply and Sum Algorithm for Clutter Removal in a Microwave Breast Tumor Imaging System." Applied Sciences 14, no. 9 (April 30, 2024): 3820. http://dx.doi.org/10.3390/app14093820.

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In the medical field, microwave imaging technology has experienced rapid development due to its non-invasive and non-radioactive nature. The confocal algorithm is a method commonly used for microwave breast cancer imaging, with the key objective of removing clutter in images to achieve high-quality results. However, the current methods are facing challenges in removing clutter. In order to reduce the clutter in images, a multiplicative improved coherence factor delay multiply and sum algorithm based on the maximum interclass differencing method is proposed. The algorithm compares the starting and ending moments of tumor signals in different channels to determine whether the tumor-scattered signals in different channels overlap in time. An improved coherence coefficient is obtained by summing the non-overlapping signals and multiplying the time window. The multiplicative improved coherence factor, which is obtained by multiplying the coherence coefficients of the improved multi-pair signals, is then multiplied by the focal point intensity obtained using the delay multiply and sum algorithm to reduce clutter in an image. To evaluate the performance of the proposed algorithm, several low-cost uniform and non-uniform models of human breast and tumor tissue with dielectric properties were prepared for testing. The experimental results show that, compared to the existing algorithm, the proposed algorithm can greatly reduce the clutter in images, with a signal-to-clutter ratio of at least 4 dB higher as well as contrast at least six-fold higher.

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Elekonawo, Fortuné M. K., Jan Marie de Gooyer, Desirée L. Bos, David M. Goldenberg, Otto C. Boerman, Lodewijk A. A. Brosens, Andreas J. A. Bremers, Johannes H. W. de Wilt, and Mark Rijpkema. "Ex Vivo Assessment of Tumor-Targeting Fluorescent Tracers for Image-Guided Surgery." Cancers 12, no. 4 (April 17, 2020): 987. http://dx.doi.org/10.3390/cancers12040987.

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Image-guided surgery can aid in achieving complete tumor resection. The development and assessment of tumor-targeted imaging probes for near-infrared fluorescence image-guided surgery relies mainly on preclinical models, but the translation to clinical use remains challenging. In the current study, we introduce and evaluate the application of a dual-labelled tumor-targeting antibody for ex vivo incubation of freshly resected human tumor specimens and assessed the tumor-to-adjacent tissue ratio of the detectable signals. Immediately after surgical resection, peritoneal tumors of colorectal origin were placed in cold medium. Subsequently, tumors were incubated with 111In-DOTA-hMN-14-IRDye800CW, an anti-carcinoembryonic antigen (CEA) antibody with a fluorescent and radioactive label. Tumors were then washed, fixed, and analyzed for the presence and location of tumor cells, CEA expression, fluorescence, and radioactivity. Twenty-six of 29 tumor samples obtained from 10 patients contained malignant cells. Overall, fluorescence intensity was higher in tumor areas compared to adjacent non-tumor tissue parts (p < 0.001). The average fluorescence tumor-to-background ratio was 11.8 ± 9.1:1. A similar ratio was found in the autoradiographic analyses. Incubation with a non-specific control antibody confirmed that tumor targeting of our tracer was CEA-specific. Our results demonstrate the feasibility of this tracer for multimodal image-guided surgery. Furthermore, this ex vivo incubation method may help to bridge the gap between preclinical research and clinical application of new agents for radioactive, near infrared fluorescence or multimodal imaging studies.

35

Samani, N. J., A. K. Ruprai, W. J. Brammar, and J. D. Swales. "The renin gene in patients with malignant hypertension and raised plasma renin activity." Clinical Science 76, no. 2 (February 1, 1989): 151–55. http://dx.doi.org/10.1042/cs0760151.

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1. We have examined the hypothesis that the raised plasma renin activity in patients with malignant hypertension without an underlying cause is the consequence of expression of a duplicate renin gene. 2. DNA extracted from leucocytes of patients with malignant hypertension and of normotensive controls was digested with the restriction endonuclease PstI and hybridized with a radioactively labelled human renin complementary DNA probe. As an internal control the DNA was concurrently hybridized with a human c-myc protooncogene probe. 3. The signals for each subject from the two probes were quantitatively compared by densitometry. 4. There was no evidence of duplication of the renin gene in the patients with malignant hypertension.

36

Lei, Jian Ming, Xiin Zeng, and Xue Cheng Zou. "The System of Signal Detection Based on Sensing Needle." Advanced Materials Research 544 (June 2012): 218–22. http://dx.doi.org/10.4028/www.scientific.net/amr.544.218.

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Biologic systems frequently have electric activity associated with them. This activity can be a constant dc electric field, a constant flux of charge-carrying particles or current, or a time-varying electric field or current associated with some time-dependent biologic or biochemical phenomenon. The mechanism of electric conductivity in the body involves ions as charge carriers. Thus, picking up bioelectric signals involves interacting with these ionic charge carriers and transducing ionic currents into electric currents required by wires and electronic instrumentation. Calcium ion is so important in our body, which plays a crucial role in metabolism.The common methods of detecting calcium ion include radioactive tracer method, activation shine protein method, etc, we choose calcium ion sensing needle as a tool to detect the calcium ion in the acupoint.

37

Thangabalan Boovizhikannan, Jagadish Kuruba, Mahasweta Goswami, and Bhavya Maddineni. "Analytical estimation methods for determination of sorafenib." World Journal of Biology Pharmacy and Health Sciences 12, no. 2 (November 30, 2022): 016–26. http://dx.doi.org/10.30574/wjbphs.2022.12.2.0184.

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Sorafenib is an anticancer drug is used to treat late stage kidney and liver cancer. Sorafenib is used to treat advanced renal cell carcinoma (RCC; a type of cancer that begins in the kidneys). Sorafenib is also used to treat hepatocellular carcinoma (a type of liver cancer) that cannot be treated with surgery and a certain type of thyroid cancer that has spread to other parts of the body and cannot be treated with radioactive iodine. Sorafenib is in a class of medications called kinase inhibitors. It works by blocking the action of an abnormal protein that signals cancer cells to multiply. This helps stop the spread of cancer cells. There are many reported analytical methods for estimation of Sorafenib. The present work list outs the various analytical methods for the estimation of the drug.

38

Speel, E. J., B. Schutte, J. Wiegant, F. C. Ramaekers, and A. H. Hopman. "A novel fluorescence detection method for in situ hybridization, based on the alkaline phosphatase-fast red reaction." Journal of Histochemistry & Cytochemistry 40, no. 9 (September 1992): 1299–308. http://dx.doi.org/10.1177/40.9.1506667.

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We have used naphthol-ASMX-phosphate and Fast Red TR in combination with alkaline phosphatase (APase) to produce fluorescent precipitated reaction products in a non-radioactive in situ hybridization (ISH) method. To obtain optimal and discrete localization of the strongly red fluorescent ISH signals, the enzyme precipitation procedure was optimized. The optimal reaction time and the concentrations of substrate and capture agent were determined. Furthermore, polyvinyl alcohol (PVA) was used to increase the viscosity of the reaction mixture and thus to reduce diffusion of the reaction product. Our results show that the APase-Fast Red detection method has at least the same sensitivity as currently observed in other immunofluorescent detection systems. A single copy DNA sequence of 15.8 KB could be localized with high efficiency in metaphase spreads and in interphase nuclei. Double labeling procedures, in which the FITC- and azo-dye fluorescence are combined, are also feasible. The red fluorescent ISH signals showed hardly any fading as compared with FITC fluorescence on exposure to either light from the mercury-arc lamp or laser light. Therefore, these red fluorescent signals with a virtually permanent character allow a better analysis and three-dimensional localization of such cytochemically detected genomic fractions by means of confocal scanning laser microscopy as compared with the use of FITC, TRITC, or Texas Red as label.

39

Kim, Hye Mi, Hyeyeong Seo, Yooheon Park, Hee-Seok Lee, Seok-Hee Lee, and Kwang Suk Ko. "Development of a Human Estrogen Receptor Dimerization Assay for the Estrogenic Endocrine-Disrupting Chemicals Using Bioluminescence Resonance Energy Transfer." International Journal of Environmental Research and Public Health 18, no. 16 (August 23, 2021): 8875. http://dx.doi.org/10.3390/ijerph18168875.

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Endocrine-disrupting chemicals (EDCs) are found in food and various other substances, including pesticides and plastics. EDCs are easily absorbed into the body and have the ability to mimic or block hormone function. The radioligand binding assay based on the estrogen receptors binding affinity is widely used to detect estrogenic EDCs but is limited to radioactive substances and requires specific conditions. As an alternative, we developed a human cell-based dimerization assay for detecting EDC-mediated ER-alpha (ERα) dimerization using bioluminescence resonance energy transfer (BRET). The resultant novel BRET-based on the ERα dimerization assay was used to identify the binding affinity of 17β-estradiol (E2), 17α-estradiol, corticosterone, diethylhexyl phthalate, bisphenol A, and 4-nonylphenol with ERα by measuring the corresponding BRET signals. Consequently, the BRET signals from five chemicals except corticosterone showed a dose-dependent sigmoidal curve for ERα, and these chemicals were suggested as positive chemicals for ERα. In contrast, corticosterone, which induced a BRET signal comparable to that of the vehicle control, was suggested as a negative chemical for ERα. Therefore, these results were consistent with the results of the existing binding assay for ERα and suggested that a novel BRET system can provide information about EDCs-mediated dimerization to ERα.

40

Schimmel, Carmel, David Frazer, and Robb W. Glenny. "Extending fluorescent microsphere methods for regional organ blood flow to 13 simultaneous colors." American Journal of Physiology-Heart and Circulatory Physiology 280, no. 6 (June 1, 2001): H2496—H2506. http://dx.doi.org/10.1152/ajpheart.2001.280.6.h2496.

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Seven fluorescent microsphere colors can be used in a single experiment to estimate regional blood flow without correcting for spillover of emitted fluorescence. To extend the method to 13 colors, we compared the accuracy of three methods for spillover correction. Fixed wavelength intensities were corrected by matrix inversion, and synchronous scan spectra were corrected by least squares fit of an overdetermined system of linear equations and by least squares fit of a sum of Gaussian and Lorentzian functions. Correction methods were validated in pigs and sheep by simultaneous injections of radioactive microspheres and fluorescent microspheres of 7, 10, and 13 different colors. We induced extreme changes in flow to create regions with low fluorescent signals bound on either side by high fluorescent signals. Blood flow was determined by radioactivity and by fluorescence using both fixed excitation and emission wavelength pairs and synchronous scanning and then corrected for spillover. Correlation between fluorescent intensity and radioactivity were excellent for all three correction methods [ R 2 = 0.98 ± 0.02 (mean ± SD)]. Low-flow regions requiring large spillover correction had systematic errors for some color combinations in all methods. We conclude that for 13 fluorescent colors spillover error can be minimized so that all three correction methods provide accurate estimates of regional blood flow.

41

Prabhakara, Prathik, Frank Mielentz, Heiko Stolpe, Matthias Behrens, Vera Lay, and Ernst Niederleithinger. "Validation of Novel Ultrasonic Phased Array Borehole Probe by Using Simulation and Measurement." Sensors 22, no. 24 (December 14, 2022): 9823. http://dx.doi.org/10.3390/s22249823.

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Low-frequency ultrasonic testing is a well-established non-destructive testing (NDT) method in civil engineering for material characterization and the localization of cracks, reinforcing bars and delamination. A novel ultrasonic borehole probe is developed for in situ quality assurance of sealing structures in radioactive waste repositories using existing research boreholes. The aim is to examine the sealing structures made of salt concrete for any possible cracks and delamination and to localize built-in components. A prototype has been developed using 12 individual horizontal dry point contact (DPC) shear wave transducers separated by equidistant transmitter/receiver arrays. The probe is equipped with a commercially available portable ultrasonic flaw detector used in the NDT civil engineering industry. To increase the sound pressure generated, the number of transducers in the novel probe is increased to 32 transducers. In addition, the timed excitation of each transducer directs a focused beam of sound to a specific angle and distance based on the previously calculated delay time. This narrows the sensitivity of test volume and improves the signal-to-noise ratio of the received signals. In this paper, the newly designed phased array borehole probe is validated by beam computation in the CIVA software and experimental investigations on a half-cylindrical test specimen to investigate the directional characteristics. In combination with geophysical reconstruction methods, it is expected that an optimised radiation pattern of the probe will improve the signal quality and thus increase the reliability of the imaging results. This is an important consideration for the construction of safe sealing structures for the safe disposal of radioactive or toxic waste.

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RAPP, P. E., T. A. A. WATANABE, P. FAURE, and C. J. CELLUCCI. "NONLINEAR SIGNAL CLASSIFICATION." International Journal of Bifurcation and Chaos 12, no. 06 (June 2002): 1273–93. http://dx.doi.org/10.1142/s021812740200508x.

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In this contribution, we show that the incorporation of nonlinear dynamical measures into a multivariate discrimination provides a signal classification system that is robust to additive noise. The signal library was composed of nine groups of signals. Four groups were generated computationally from deterministic systems (van der Pol, Lorenz, Rössler and Hénon). Four groups were generated computationally from different stochastic systems. The ninth group contained inter-decay interval sequences from radioactive cobalt. Two classification criteria (minimum Mahalanobis distance and maximum Bayesian likelihood) were tested. In the absence of additive noise, no errors occurred in a within-library classification. Normally distributed random numbers were added to produce signal to noise ratios of 10, 5 and 0 dB. When the minimum Mahalanobis distance was used as the classification criterion, the corresponding error rates were 2.2%, 4.4% and 20% (Expected Error Rate = 89%). When Bayesian maximum likelihood was the criterion, the error rates were 1.1%, 4.4% and 21% respectively. Using nonlinear measures an effective discrimination can be achieved in cases where spectral measures are known to fail. Most classification errors occurred at low signal to noise ratios when a stochastic signal was misclassified into a different group of stochastic signals. When the within-library classification exercise is limited to the four groups of deterministic signals, no classification errors occurred with clean data, at SNR = 10 dB, or at SNR = 5 dB. A single classification error (Observed Error Rate = 2.5%, Expected Error Rate = 75%) occurred with both classification criteria at SNR = 0 dB.

43

Pinaroli, G., S. Herrmann, S. Miryala, V. Manthena, G. W. Deptuch, G. A. Carini, A. E. Bolotnikov, et al. "Multi-channel front-end ASIC for a 3D position-sensitive detector." Journal of Instrumentation 17, no. 02 (February 1, 2022): C02011. http://dx.doi.org/10.1088/1748-0221/17/02/c02011.

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Abstract Arrays of 3D position-sensitive detectors (3DPSD), operating at room temperature and using cadmium zinc telluride (CZT) and thallium bromide (TIBr) sensors, are suitable for gamma-ray spectrometry in many applications. One detector configuration, the 3D position-sensitive Virtual Frisch-Grid detector (VFG), is particularly advantageous for integrating into large area arrays. The signals generated inside each detector of the array are captured with the anode, cathode and four pads that enable the reconstruction of the position and energy of the ionizing interaction by measurements of amplitude and timing of the signals. For these applications, a low-noise front-end ASIC has been developed, capable of processing bipolar signals (needed because of AC-coupling of certain electrodes). The ASIC can be coupled to an ADC in order to form a compound “waveform digitizer” capable of post-processing the analog signals and determining amplitude and timing information. This paper describes a 32-channel front-end ASIC that is suitable for reading out a 3 × 3 or 4 × 4 element matrix in the VFG configuration. Each channel is composed of a low-noise charge amplifier with an adaptive continuous reset feedback circuit suitable for both positive and negative charge, a first order shaper and a single-to-differential converter output stage. Voltage and current references are all internally generated by 10-bit DACs and the chip is fully controllable with the I2C communication protocol. The readout channel response has been verified using the implemented injection circuit. Linear behavior up to ∼75 ke± with the gain of ∼80 mV/fC, and up to ∼200 ke± with the gain of ∼30 mV/fC was demonstrated. In conclusion, the first test result waveforms using a 137Cs radioactive source on a 5 × 5 × 12 mm3 TIBr crystal are reported.

44

Silva, Ricardo F., Jorge M. Sampaio, Pedro Amaro, Andreas Flörs, Gabriel Martínez-Pinedo, and José P. Marques. "Structure Calculations in Nd III and U III Relevant for Kilonovae Modelling." Atoms 10, no. 1 (February 7, 2022): 18. http://dx.doi.org/10.3390/atoms10010018.

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The detection of gravitational waves and electromagnetic signals from the neutron star merger GW170817 has provided evidence that these astrophysical events are sites where the r-process nucleosynthesis operates. The electromagnetic signal, commonly known as kilonova, is powered by the radioactive decay of freshly synthesized nuclei. However, its luminosity, colour and spectra depend on the atomic opacities of the produced elements. In particular, opacities of lanthanides and actinides elements, due to their large density of bound–bound transitions, are fundamental. The current work focuses on atomic structure calculations for lanthanide and actinide ions, which are important in kilonovae modelling of ejecta spectra. Calculations for Nd III and U III, two representative rare-earth ions, were achieved. Our aim is to provide valuable insights for future opacity calculations for all heavy elements. We noticed that the opacity of U III is about an order of magnitude greater than the opacity of Nd III due to a higher density of levels in the case of the actinide.

45

Yeom, Yun-Taek, Yeong-Won Choi, Hak-Joon Kim, Hun-Hee Kim, Jae-Suk Park, Sung-Woo Ryu, and Sung-Jin Song. "Containment Liner Plate Void Defect Detection Technique Using Phased Array Ultrasonic Testing and Acoustic Resonance Method." Materials 15, no. 4 (February 11, 2022): 1330. http://dx.doi.org/10.3390/ma15041330.

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The CLP (containment liner plate) of a nuclear power plant protects the internal system from the external environment and sudden changes in internal pressure or temperature, and it is a structure that blocks and protects radioactive materials leaking inside and outside in the event of a nuclear accident and is composed of a liner plate, reinforcing bars, tendons, and concrete. Recently, corrosion on the rear side of the liner plate and concrete voids has emerged as a severe defect in nuclear power plants across South Korea. Therefore, in this study, we proposed a new inspection method that a line-type inspection method applied phased array ultrasonic testing and the area inspection method applied acoustic resonance method using developed moveable tapper. The acoustic signals were signal-processed and reproduced to a mapping image following the inspection area, and with the image, it was possible to determine the type of defect. Furthermore, an automated inspection system for within the CLP was proposed.

46

Zych, Marcin. "Prospects for the application of radiometric methods in the measurement of two-phase flows." EPJ Web of Conferences 180 (2018): 01001. http://dx.doi.org/10.1051/epjconf/201818001001.

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The article constitutes an overview of the application of radiometric methods in the research of two-phase flows: liquid-solid particles and liquid-gas flows. The methods which were used were described on the basis of the experiments which were conducted in the Water Laboratory of the Wrocław University of Environmental and Life Sciences and in the Sedimentological Laboratory of the Faculty of Geology, Geophysics and Environmental Protection, AGH-UST in Kraków. The advanced mathematical methods for the analysis of signals from scintillation probes that were applied enable the acquisition of a number of parameters associated with the flowing two-phase mixture, such as: average velocities of the particular phases, concentration of the solid phase, and void fraction for a liquid-gas mixture. Despite the fact that the application of radioactive sources requires considerable carefulness and a number of state permits, in many cases these sources become useful in the experiments which are presented.

47

Choi, Sang Woo, and Joon Hyun Lee. "Application of Ultrasonic Phased Array Techniques for Inspection of Stud Bolts in Nuclear Power Plants." Solid State Phenomena 110 (March 2006): 97–104. http://dx.doi.org/10.4028/www.scientific.net/ssp.110.97.

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The reactor vessel body and closure head are fastened with the stud bolt that is one of crucial parts for safety of the reactor vessels in nuclear power plants. It is reported that the stud bolt is often experienced by fatigue cracks initiated at threads. Stud bolts are inspected by the ultrasonic technique during the overhaul periodically for the prevention of failure which leads to radioactive leakage from the nuclear reactor. The conventional ultrasonic inspection for stud bolts was mainly conducted by reflected echo method based on shadow effect. However, in this technique, there were numerous spurious signals reflected from every oblique surfaces of the thread. In this study, ultrasonic phased array technique was applied to investigate detectability of flaws in stud bolts and characteristics of ultrasonic images corresponding to different scanning methods, that is, sector and linear scan. For this purpose, simplified stud bolt specimens with artificial defects of various depths were prepared.

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Tanaka, Masaomi, Daiji Kato, Gediminas Gaigalas, Kyohei Kawaguchi, Laima Radžiūtė, Pavel Rynkun, Smaranika Banerjee, and Nanae Domoto. "Modeling kilonova emission from neutron star mergers." Proceedings of the International Astronomical Union 16, S363 (June 2020): 127–34. http://dx.doi.org/10.1017/s1743921322000850.

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AbstractCoalescence of binary neutron stars gives rise to kilonova, thermal emission powered by radioactive decays of newly synthesized r-process nuclei. Observational properties of kilonova are largely affected by bound-bound opacities of r-process elements. It is, thus, important to understand atomic properties of heavy elements to link the observed signals with nucleosynthesis of neutron star mergers. In this paper, we introduce the latest status of kilonova modeling by focusing on the aspects of atomic physics. We perform systematic atomic structure calculations of r-process elements to understand element-to-element variation in the opacities. We demonstrate that the properties of the atomic structure of heavy elements are imprinted in the opacities of the neutron star merger ejecta and consequently in the kilonova light curves and spectra. Using this latest opacity dataset, we briefly discuss implications for GW170817, expected diversity of kilonova emission, and prospects for element identification in kilonova spectra.

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Huang, Hanzhi. "Current status and applications of time-to-digital converters." Applied and Computational Engineering 53, no. 1 (March 28, 2024): 79–83. http://dx.doi.org/10.54254/2755-2721/53/20241275.

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Time-to-Digital Converter (TDC) is widely used to realize time interval measurement. The high-precision time measurement technique has important applications in the fields of laser ranging, particle identification, and radioactive nuclear medicine engineering. Based on the existing literature research and data, this paper studies the application areas of TDC in the present development and analyzes the future prospects of TDC applications. The research results showed that: TDC, based on signal screening, realizes time interval measurement as the ultimate purpose of building the system and, at the same time, completes the function of multi-pulse time interval measurement, which can meet the needs of more diversified measurements in the experiments. In the circuit structure, it can identify the feedback output in the all-digital phase-locked loop (ADPLL) and the reference clock phase and frequency information between the feedback output and the reference clock in an ADPLL. It is also promising for use in other areas of high-precision time measurement and processing of circuit signals.

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Guo, Cheng, Yan Zhang, Yuan Hu, Wanchang Lai, and Qing Zhao. "Pulse Signal Generator for Simulated Gamma-ray Spectrometer Detection." Journal of Physics: Conference Series 2747, no. 1 (May 1, 2024): 012053. http://dx.doi.org/10.1088/1742-6596/2747/1/012053.

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Abstract This paper introduces an integrated nuclear pulse generator aimed at simulating authentic radiation detection signals, allowing for the convenient calibration and testing of nuclear instruments without the need for radioactive sources. An innovative method is adopted, generating energy spectrum distributions via Monte Carlo simulation and deriving nuclear pulse waveforms using difference equations. This approach enables real-time computation of particle transport processes on a hardware platform, and generates pulse sequences that closely resemble the statistical characteristics of actual nuclear events. Compared to traditional nuclear signal generators, this new type of generator significantly enhances the flexibility and real-time capabilities of the equipment, as it no longer relies on pre-stored empirical data or simulation software to generate energy spectrum data. As a case for gamma-ray spectrometer detection, the signal waveforms and energy spectrum distributions produced closely match those obtained using a NaI scintillation detector in a lead chamber to detect a Cs-137 source.

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