Articoli di riviste: "Gamma rays"

1

Musser, George. "Gamma Rays". Scientific American 301, n. 3 (settembre 2009): 94. http://dx.doi.org/10.1038/scientificamerican0909-94b.

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2

Chi, X., e A. W. Wolfendale. "Extragalactic gamma rays". Journal of Physics G: Nuclear and Particle Physics 15, n. 9 (1 settembre 1989): 1509–18. http://dx.doi.org/10.1088/0954-3899/15/9/019.

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3

Zarifmahmoudi, Leili, e Ramin Sadeghi. "Scattered gamma rays". Nuclear Medicine Communications 36, n. 7 (luglio 2015): 755–56. http://dx.doi.org/10.1097/mnm.0000000000000324.

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4

Danilyan, G. V., J. Klenke, V. A. Krakhotin, V. L. Kuznetsov, V. V. Novitsky, V. S. Pavlov e P. B. Shatalov. "Scission gamma rays". Physics of Atomic Nuclei 72, n. 11 (novembre 2009): 1812–17. http://dx.doi.org/10.1134/s1063778809110027.

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5

May, M. "Hypernuclear gamma rays". Nuclear Physics A 450 (marzo 1986): 179–88. http://dx.doi.org/10.1016/0375-9474(86)90552-x.

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6

Sun, Y. K., H. T. Jing, B. B. Tian, X. L. Gao e X. Y. Yang. "Research on proton beam spot imaging based on pixelated gamma detector". Journal of Instrumentation 17, n. 02 (1 febbraio 2022): P02033. http://dx.doi.org/10.1088/1748-0221/17/02/p02033.

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Abstract The secondary particles from the spallation target of the China Spallation Neutron Source are mainly gammas and neutrons, which are related to the incident proton. The reconstruction of the proton beam spot could be implemented based on the distribution of the positions of secondary gammas or neutrons. The methods of pinhole imaging and Compton imaging are developed by measuring the position distribution of gammas based on the pixelated detector. The secondary gammas could be detected by the pixelated gamma detector directly. The neutron can be identified by detecting the characteristic (478 keV) γ-rays from the 10B(n, α) reactions. In order to detect secondary neutrons, a layer of 10B converter is added before the pixelated gamma detector. The pixelated gamma detector is sensitive to the characteristic (478 keV) γ-rays and then the neutron imaging could be achieved based on measuring the position distribution of the characteristic (478 keV) γ-rays.

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7

Kasztelan, M., K. Jȩdrzejczak e J. Szabelski. "Comparison of MC Geant4 simulation with the measurements of gamma photons produced by neutrons". Modern Physics Letters A 34, n. 06 (28 febbraio 2019): 1950046. http://dx.doi.org/10.1142/s0217732319500469.

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In this work, we have focused on results of measurements of the hydrogen line 2223 keV and compared them with the results of Geant4 simulations. The paraffin containing hydrogen was irradiated by neutrons produced by the weak AmBe source. Produced gammas were measured with the germanium detector. The experimental setup was placed inside a carbon chamber which provided the shielding from the external neutrons. The measurements were performed for different amounts of paraffin. The processes playing a role in the description of our measurements are transport and moderation of neutrons, production of gamma rays in neutron-hydrogen interactions, transport and detection of gamma rays. It has been shown that the correctly carried out Monte Carlo simulations reproduced the measured values of the intensity of the observed gamma line 2223 keV from the neutron capture on hydrogen. The absorption of gamma rays is also described correctly. This has been shown in comparing the measurements of gamma line 322 keV from [Formula: see text]Pb with the simulations.

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8

Koshikawa, N., A. Omata, M. Masubuchi, Y. Okazaki, J. Kataoka, K. Matsunaga, H. Kato, A. Toyoshima, Y. Wakabayashi e T. Kobayashi. "Activation imaging of drugs with hybrid Compton camera: A proof-of-concept study". Applied Physics Letters 121, n. 19 (7 novembre 2022): 193701. http://dx.doi.org/10.1063/5.0116570.

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The visualization of drugs is essential for cancer treatment. Although several methods for visualizing drugs have been proposed, a versatile method that can be easily applied to various drugs has not yet been established. Therefore, we propose “activation imaging,” in which a drug is irradiated with thermal neutrons and becomes radioactive, enabling visualization using emitted x rays and/or gamma rays. Activation imaging does not require the conjugation of specific tracers with drugs. Therefore, it can be easily applied to a variety of drugs, drug carriers (e.g., metal nanoparticles), and contrast agents. In this study, neutron activation, gamma-ray spectroscopy, and imaging of drug carriers, anticancer drug, and contrast agents were performed. Gold nanoparticles (AuNPs) and platinum nanoparticles were used as drug carriers, cisplatin was used as an anticancer drug, and gadoteridol and iohexol were used as contrast agents. As a neutron source, the RIKEN accelerator-driven compact neutron source II (RANS-II) was utilized. The imaging was performed using a hybrid Compton camera (HCC). The HCC can visualize x rays and gamma rays ranging from a few keV to nearly 1 MeV, which enables the imaging of various x rays and gamma rays emitted from the activated drugs. As a result, the gamma-ray spectra indicated the generation of radioisotopes through neutron irradiation, and AuNPs and iohexol were visualized.

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9

Osborne, J. L., A. W. Wolfendale e L. Zhang. "Soft X-rays and cosmic gamma-rays". Monthly Notices of the Royal Astronomical Society 276, n. 2 (15 settembre 1995): 409–16. http://dx.doi.org/10.1093/mnras/276.2.409.

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10

Leising, Mark D. "Gamma-rays and X-rays from SN1987A". Nature 332, n. 6164 (aprile 1988): 516–18. http://dx.doi.org/10.1038/332516a0.

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11

Gan, Weiqun, Jin Chang, Youping Li e Chunmei Lin. "Solar hard X-rays and gamma-rays". Science in China Series A: Mathematics 45, S1 (ottobre 2002): 30–35. http://dx.doi.org/10.1007/bf02889681.

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12

López, J. A., S. S. Romero González, O. Hernández Rodríguez, J. Holmes e R. Alarcon. "GEANT4 Study of Proton–Body Interactions". Journal of Nuclear Physics, Material Sciences, Radiation and Applications 8, n. 2 (10 febbraio 2021): 121–27. http://dx.doi.org/10.15415/jnp.2021.82015.

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Proton therapy uses a beam of protons to destroy cancer cells. A problem of the method is the determination of what part of the body the protons are hitting during the irradiation. In a previous study we determine that by capturing the gamma rays produced during the irradiation one can determine the location of the proton-body interaction, in this work we investigate if by examining the gamma rays produced it is possible to determine the body part that produced the gamma rays by the proton collision. This study uses GEANT4 computer simulations of interactions of proton-tissue, protonbrain, proton-bone, etc., which produce gamma rays, to determine the characteristics of the gamma rays produced. We then analyze the characteristics of the gamma rays to find signatures that could be used to determine the source of the rays. In particular, we study the distribution of gamma ray energies, their full-width half-maximum, energy resolution, maximum height, and total number of counts. This study concludes that it is possible to use the gamma ray spectra to determine what body part produced it.

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13

Allison, Ron, e James P. Vaughan. "Gamma Rays Combat Restenosis". Science News 152, n. 15 (11 ottobre 1997): 235. http://dx.doi.org/10.2307/3981104.

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14

Pockley, Peter. "Gamma rays down under". Physics World 13, n. 5 (maggio 2000): 7. http://dx.doi.org/10.1088/2058-7058/13/5/8.

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15

Frahm, Ronald. "Science with Gamma Rays". Synchrotron Radiation News 22, n. 3 (giugno 2009): 2. http://dx.doi.org/10.1080/08940880902959726.

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16

SHAHAM, JACOB. "Galactic halo gamma rays". Nature 354, n. 6353 (dicembre 1991): 439. http://dx.doi.org/10.1038/354439a0.

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17

Benka, Stephen G. "Gamma rays from thunderclouds". Physics Today 60, n. 10 (ottobre 2007): 26. http://dx.doi.org/10.1063/1.4797447.

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18

Shvets, Gennady. "Gamma-rays going cheap". Nature Physics 7, n. 11 (18 settembre 2011): 834–35. http://dx.doi.org/10.1038/nphys2110.

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19

Mukherjee, R. "High energy gamma rays". Nuclear Physics B - Proceedings Supplements 91, n. 1-3 (gennaio 2001): 480–86. http://dx.doi.org/10.1016/s0920-5632(00)00978-6.

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20

WALDROP, M. M. "Gamma Rays for Christmas". Science 239, n. 4835 (1 gennaio 1988): 26. http://dx.doi.org/10.1126/science.239.4835.26.

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21

Leising, M. D. "Focusing supernova gamma rays". Experimental Astronomy 20, n. 1-3 (16 settembre 2006): 49–55. http://dx.doi.org/10.1007/s10686-006-9052-3.

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22

Trubnikov, B. A. "Cosmic rays and gamma-ray bursts". Uspekhi Fizicheskih Nauk 167, n. 3 (1997): 345. http://dx.doi.org/10.3367/ufnr.0167.199703k.0345.

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23

Zuo, Yinghong, Maoyu Zhang, Guoxin Cheng e Shengli Niu. "Study on Induced Current of Iron Plate Irradiated by Pulsed Gamma Rays". E3S Web of Conferences 53 (2018): 01007. http://dx.doi.org/10.1051/e3sconf/20185301007.

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To obtain the transient current response law of the metal component irradiated by pulsed gamma rays, the pulsed gamma ray irradiation experiment of the iron plate was carried out on “Qiangguang-I” accelerator. The transient current of iron plate generated by pulsed gamma rays was measured and analysed, and the relationship between the amplitude of pulse current and the dose rate of gamma rays was obtained. The results show that the current response sensitivity of the iron plate is about 5.7×10-7(A/m2)/(Gy/s) when the gamma rays with the energy of 0.8 MeV irradiate the iron plate. The charge deposition rate in the iron plate can be obtained by Monte Carlo simulation, and then it can be converted to gamma ray induced current of the metal component irradiated by gamma rays.

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24

Song, Ruiqiang, Shuo Peng, Yufeng Tong, Qi Wu, Sen Qian, Zhigang Wang e Jifeng Han. "The Neutron-Gamma Pulse Shape Discrimination of CLLB Detector". EPJ Web of Conferences 295 (2024): 09031. http://dx.doi.org/10.1051/epjconf/202429509031.

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Cs2LiLaBr6: Ce (CLLB) scintillator with the size of Φ 21mm × 25 mm coupled with PMT was used to detect neutron and gamma rays. The pulse shape discrimination (PSD) of neutrons and gamma rays by charge comparison method, the neutrons and gamma rays from AmBe source and fast neutron beam can be separated with figure-of-merit (FOM) values of 0.9 and 1.3, respectively. However, some neutron and gamma rays are difficult to distinguish, so new algorithms need to be investigated to improve the PSD performance of neutron and gamma. Artificial neural networks (ANN) have a very good image recognition capability, thus the ANN model was constructed to discriminate the waveforms of neutron and gamma rays. After ANN model training, the neutron and gamma signals of the CLLB detector were recognized with an accuracy of 98%, and the FOM value of the ANN method was calculated to be 19.4. This result is much higher than the charge comparison method, indicating better discrimination between neutrons and gamma rays with the ANN method.

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25

Bharathi, T., S. Gnanamurthy, D. Dhanavel e M. Ariraman. "Induced Physical Mutagenesis and its Effect in Cytological Behavior of Ashwagandha (Withania somnifera (L.) Dunal)". International Letters of Natural Sciences 17 (giugno 2014): 152–61. http://dx.doi.org/10.18052/www.scipress.com/ilns.17.152.

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The mitotic effect of physical mutagen gamma rays was observed in the root tip cells of Ashwagandha. The Chromosome analysis has been showed as an important tool for establish variability of the plant seed by use of physical mutagen gamma rays. The gamma rays have of low wavelength and high penetrable power. The plant has tremendous medicinal values and it is known from ancient times. The dry and well matured seeds of ashwagandha were irradiated with different doses of gamma rays viz., 5, 10, 15, 20, 25, 30, 35, 40, 45 and 50 KR respectively. The chromosome number of control plant is 2n = 48. The gamma rays affect the normal cytological behavior of ashwagandha species. The chromosomal aberrations increase with increase in the doses of gamma rays to optimum level of 30KR, because it causes changes in the chromosome structure, cellular structure and metabolism of plants. The chromosome aberration like, Sticky metaphase, Precocious moment chromosome, Fragments, Anaphasic bridge, Anaphasic laggard, Telophasic laggard. The present investigation was carried out to study the cytogenetic analysis of the species Withania somnifera. The chromosomal aberration increases with increase in the doses to optimum level (50 KR) of physical mutagen gamma rays.

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26

Bharathi, T., S. Gnanamurthy, D. Dhanavel e M. Ariraman. "Induced Physical Mutagenesis and its Effect in Cytological Behavior of Ashwagandha (<i>Withania somnifera</i> (L.) Dunal)". International Letters of Natural Sciences 17 (30 giugno 2014): 152–61. http://dx.doi.org/10.56431/p-44g1js.

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The mitotic effect of physical mutagen gamma rays was observed in the root tip cells of Ashwagandha. The Chromosome analysis has been showed as an important tool for establish variability of the plant seed by use of physical mutagen gamma rays. The gamma rays have of low wavelength and high penetrable power. The plant has tremendous medicinal values and it is known from ancient times. The dry and well matured seeds of ashwagandha were irradiated with different doses of gamma rays viz., 5, 10, 15, 20, 25, 30, 35, 40, 45 and 50 KR respectively. The chromosome number of control plant is 2n = 48. The gamma rays affect the normal cytological behavior of ashwagandha species. The chromosomal aberrations increase with increase in the doses of gamma rays to optimum level of 30KR, because it causes changes in the chromosome structure, cellular structure and metabolism of plants. The chromosome aberration like, Sticky metaphase, Precocious moment chromosome, Fragments, Anaphasic bridge, Anaphasic laggard, Telophasic laggard. The present investigation was carried out to study the cytogenetic analysis of the species Withania somnifera. The chromosomal aberration increases with increase in the doses to optimum level (50 KR) of physical mutagen gamma rays.

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27

Huang, Tian-Qi, e Zhuo Li. "Constraints on Hadronic Contributions to LHAASO Sources with Neutrino Observations". Astrophysical Journal 925, n. 1 (1 gennaio 2022): 85. http://dx.doi.org/10.3847/1538-4357/ac423d.

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Abstract The Large High Altitude Air Shower Observatory (LHAASO) detected 12 gamma-ray sources above 100 TeV, which are the possible origins of Galactic cosmic-rays. We summarize the neutrino measurements by IceCube and ANTARES in the vicinity of LHAASO sources to constrain the contribution of hadronic gamma-rays in these sources. We find that the current observations constrain hadronic gamma-rays to contribute no more than ∼60% of the gamma-rays from the Crab Nebula. Gamma-rays from two LHAASO sources, LHAASO J1825−1326 and LHAASO J1907+0626, are dominated by leptonic components up to ∼200 TeV, under the hypotheses in the analysis by IceCube. The uncertainties of the constraint on the hadronic gamma-ray emission are discussed. We also constrain the total 100 TeV gamma-ray emission from TeV pulsar wind nebulae by relying on the remarkable sensitivity of LHAASO at that energy.

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28

Alhamd, M. W., Sadeq Naeem Atiyah, Firas Taqi Almusawi e Mazen Katea Al-Gharrawy. "Gamma Ray Spectrum by Software Methods for Radioactive Waste". Iraqi Journal of Industrial Research 10, n. 3 (14 dicembre 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.

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29

Naqvi, A. A., F. Z. Khiari, F. A. Liadi, Khateeb ur-Rehman, M. Raashid e A. A. Isab. "Multiple Gamma-Ray Detection Capability of a CeBr3 Detector for Gamma Spectroscopy". Journal of Spectroscopy 2017 (2017): 1–8. http://dx.doi.org/10.1155/2017/5634384.

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The newly developed cerium tribromide (CeBr3) detector has reduced intrinsic gamma-ray activity with gamma energy restricted to 1400–2200 keV energy range. This narrower region of background gamma rays allows the CeBr3 detector to detect more than one gamma ray to analyze the gamma-ray spectrum. Use of multiple gamma-ray intensities in elemental analysis instead of a single one improves the accuracy of the estimated results. Multigamma-ray detection capability of a cylindrical 75 mm × 75 mm (diameter × height) CeBr3 detector has been tested by analyzing the chlorine concentration in water samples using eight chlorine prompt gamma rays over 517 to 8578 keV energies utilizing a D-D portable neutron generator-based PGNAA setup and measuring the corresponding minimum detection limit (MDC) of chlorine. The measured MDC of chlorine for gamma rays with 517–8578 keV energies varies from 0.07 ± 0.02 wt% to 0.80 ± 0.24. The best value of MDC was measured to be 0.07 ± 0.02 wt% for 788 keV gamma rays. The experimental results are in good agreement with Monte Carlo calculations. The study has shown excellent detection capabilities of the CeBr3 detector for eight prompt gamma rays over 517–8578 keV energy range without significant background interference.

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30

Eichler, David. "Particle Acceleration in High-Energy Gamma-Ray Sources". International Astronomical Union Colloquium 142 (1994): 877–81. http://dx.doi.org/10.1017/s0252921100078246.

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AbstractMany proficient gamma-ray sources show energy spectra that are consistent with E−2 primary spectra. Such sources include recently identified gamma-ray quasars and some gamma-ray bursts. Assuming thick target conversion, this is consistent with shock acceleration, and the dominance of the gamma rays of the luminosity is also consistent with previous predictions of high production efficiency of fresh cosmic rays in shocks. The spectral cutoffs in the gamma rays may offer clues as to whether the high-energy particles are electrons or protons. Resolution of this matter might have implications for the nature of the sources and for theory of shock accelerated electrons.Subject headings: acceleration of particles — gamma rays: bursts — shock waves

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31

Dai, Ben-Zhong, e Li Zhang. "Gamma-Ray-Bright Blazars: The Spectral Properties in X-Rays and Gamma-Rays". Publications of the Astronomical Society of Japan 55, n. 5 (25 ottobre 2003): 939–45. http://dx.doi.org/10.1093/pasj/55.5.939.

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32

GHISELLINI, GABRIELE. "EXTRAGALACTIC GAMMA-RAYS: GAMMA RAY BURSTS AND BLAZARS". International Journal of Modern Physics A 20, n. 29 (20 novembre 2005): 6991–7000. http://dx.doi.org/10.1142/s0217751x05030673.

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The extragalactic gamma-ray sky is dominated by two classes of sources: Gamma-Ray Bursts (GRBs) and radio loud active galactic nuclei whose jets are pointing at us (blazars). We believe that the radiation we receive from them originates from the transformation of bulk relativistic energy into random energy. Although the mechanisms to produce, collimate and accelerate the jets in these sources are uncertain, it is fruitful to compare the characteristics of both classes of sources in search of enlightening similarities. I will review some general characteristics of radio loud AGNs and GRBs and I will discuss the possibility that both classes of sources can work in the same way. Finally, I will discuss some recent exciting prospects to use blazars to put constraints on the cosmic IR-Optical-UV backgrounds, and to use GRBs as standard candles to measure the Universe.

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33

Dermer, C. D., e G. Powale. "Gamma rays from cosmic rays in supernova remnants". Astronomy & Astrophysics 553 (26 aprile 2013): A34. http://dx.doi.org/10.1051/0004-6361/201220394.

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34

Feder, Toni. "Duke Beams Hard Gamma Rays, Soft X Rays". Physics Today 55, n. 12 (dicembre 2002): 26–27. http://dx.doi.org/10.1063/1.1537901.

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Kane, P. P. "Elastic scattering of gamma rays and X-rays". Radiation Physics and Chemistry 74, n. 6 (dicembre 2005): 402–10. http://dx.doi.org/10.1016/j.radphyschem.2005.08.004.

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Kane, P. P. "Inelastic scattering of X-rays and gamma rays". Radiation Physics and Chemistry 75, n. 12 (dicembre 2006): 2195–205. http://dx.doi.org/10.1016/j.radphyschem.2006.08.001.

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WACHTER, KERRI. "X-rays, Gamma Rays Added to Carcinogen List". Ob.Gyn. News 40, n. 6 (marzo 2005): 17. http://dx.doi.org/10.1016/s0029-7437(05)70093-8.

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38

Van Der Walt, D. J., e A. W. Wolfendale. "Gamma rays and the origin of cosmic rays". Space Science Reviews 47, n. 1-2 (marzo 1988): 1–45. http://dx.doi.org/10.1007/bf00223236.

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39

Szabelski, J., D. J. van der Walt, J. Wdowczyk e A. W. Wolfendale. "Gamma rays and the origin of cosmic rays". Advances in Space Research 9, n. 12 (gennaio 1989): 129–41. http://dx.doi.org/10.1016/0273-1177(89)90320-7.

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40

McLaughlin, Maura, e James Cordes. "Gamma Ray Pulsar Luminosities". International Astronomical Union Colloquium 177 (2000): 359–62. http://dx.doi.org/10.1017/s0252921100059996.

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AbstractWe apply a likelihood analysis to pulsar detections, pulsar upper limits, and diffuse background measurements from the OSSE and EGRET instruments to constrain theγ-rays pulsar luminosity law. We find a steeper dependence on period and magnetic field at OSSE than at EGRET energies. We also find that pulsars may be an important component of the OSSE diffuse flux, but are most likely not important for EGRET. We estimate that as many as half of the unidentified EGRET sources may beγ-rays pulsars. Furthermore, we predict that GLAST will detect roughly 1000γ-rays pulsars, only 100 of which are currently known.

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41

Sei, Norihiro, Hiroshi Ogawa e QiKa Jia. "Multiple-Collision Free-Electron Laser Compton Backscattering for a High-Yield Gamma-Ray Source". Applied Sciences 10, n. 4 (20 febbraio 2020): 1418. http://dx.doi.org/10.3390/app10041418.

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We observed multiple-collision free-electron laser (FEL)-Compton backscattering in which a multi-bunch electron beam makes head-on collisions with multi-pulse FELs in an optical cavity, using an infrared FEL system in the storage ring NIJI-IV. It was demonstrated that the measured spectrum of the multiple-collision FEL-Compton backscattering gamma rays was the summation of the spectra of the gamma rays generated at each collision point. Moreover, it was demonstrated that the spatial distribution of the multiple-collision FEL-Compton backscattering gamma rays was the summation of those of the gamma rays generated at each collision point. Our experimental results proved quantitatively that the multiple collisions in the FEL-Compton backscattering process are effective in increasing the yield of the gamma rays. By applying the multiple-collision FEL-Compton backscattering to high-repetition FEL devices such as energy recovery linac FELs, an unprecedented high-yield gamma-ray source with quasi-monochromaticity and wavelength tunability will be realized.

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42

U C, KAR, e SWAIN D. "Induced chlorophyll and macro-mutational spectrum and frequency in sesame cv.B 67". Madras Agricultural Journal 90, December (2003): 625–32. http://dx.doi.org/10.29321/maj.10.a00149.

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Seed treatment of sesame cv.B67, with EMS, NG, Gamma rays, Gamma rays EMS and Gamma rays+ NG induced five types of chlorophyll mutations and 17 types of viable macro-mutations in M,. Chlorophyll mutation frequency was the highest in 900 Gy gamma rays for single mutagen treatments and in 700 Gy + 0.04% NG for combined treatments. Macro-mutational frequencies for single and combined treatments were the highest in 0.25% EMS and 700 Gy 0.02% NG, respectively. Relative difference in mutability of gene loci for chlorophyll and macro-mutations with respect to different mutagens were clearly observed.

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43

Casanova, Sabrina. "On the Search for the Galactic PeVatrons by Means of Gamma-Ray Astronomy". Universe 8, n. 10 (26 settembre 2022): 505. http://dx.doi.org/10.3390/universe8100505.

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Cosmic rays are ultra-relativistic particles that slam into the atmosphere from all directions in the sky. Gamma rays emitted when cosmic rays interact with Galactic gas and radiation fields are a powerful tool to investigate their origin. Many candidate CR sources have been discovered in GeV-to-PeV gamma rays. However, the major contributors to the CR population, especially at the highest energies, are still unknown. We give here a state of the art report on the search for the sources of Galactic cosmic rays by means of gamma-ray astronomical methods.

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44

Bhusari, Arjun V., Mangesh R. Deshmukh e Surdesh R. Bhagat. "EFFECT OF GAMMA IRRADIATION ON MORPHOLOGICAL CHARACTERS OF MARIGOLD (Tagetes erecta L.)". World Journal of Biology and Biotechnology 2, n. 3 (15 dicembre 2017): 165. http://dx.doi.org/10.33865/wjb.002.03.0109.

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Seeds of marigold cv. ‘Pusa Narangi Gainda’ were treated with different gamma irradiation treatments viz, control, 25 Gy, 50 Gy, 75 Gy, 100 Gy, 125 Gy and 150 Gy and evaluated for various morphological characters. Reduction in survival percentage, plant height, number of branches and plant spread was observed after irradiation and with increase in exposure of gamma rays. Early flower bud initiation and flower opening was observed in lower dose of gamma rays. Flower diameter, number of flowers and length of peduncle was significantly highest at the lowest dose of gamma irradiation. The stimulatory effect of gamma irradiation was observed at 25 Gy in almost all the characters, though the intensity of inhibition increased with increasing exposures of gamma rays. On the basis of present observation, it may be concluded that irradiation of gamma rays of 25 Gy was found to be beneficial for growth and flowering characters in African marigold cv. Pusa Narangi Gainda

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45

Cheung, W. M., e K. S. Cheng. "Unpulsed High-Energy Radiation from the Crab Pulsar and Nebula". International Astronomical Union Colloquium 142 (1994): 827–31. http://dx.doi.org/10.1017/s0252921100078167.

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AbstractGenerally, people believe that the unpulsed high-energy gamma rays from the direction of Crab Nebula and pulsar comes from the nebula. But it is entirely possible that the unpulsed high-energy gamma rays from the direction of the Crab Nebula and pulsar are actually emitted from a region extending to a couple of light cylinder radii from the pulsar instead of from the extensive nebula. In this conference paper, we study the possibility that the unpulsed high-energy gamma rays from 100 MeV to 10 GeV are emitted from the extensive nebula. In our model, two pulsed photon beams from two different outer gaps cross each other beyond the light cylinder and result in pair production. Since the pitch angles of these pairs do not correlate with the local magnetic field, and the typical mean free path for pair production is comparable to the local radius of curvature, the subsequent synchrotron radiation and inverse-Compton scattering produce unpulsed X-rays and gamma-rays respectively.Subject headings: acceleration of particles — gamma rays: theory — ISM: individual (Crab Nebula) — pulsars: individual (Crab) — radiation mechanisms: nonthermal

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46

Flam, Faye. "Quasars: Ablaze With Gamma Rays". Science 256, n. 5055 (17 aprile 1992): 311. http://dx.doi.org/10.1126/science.256.5055.311.b.

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47

Flam, Faye. "Quasars: Ablaze With Gamma Rays". Science 256, n. 5055 (17 aprile 1992): 311. http://dx.doi.org/10.1126/science.256.5055.311-b.

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48

Feitzinger, J. V., e J. A. Stuwe. "Gamma rays from dark clouds". Monthly Notices of the Royal Astronomical Society 242, n. 3 (1 giugno 1990): 395–98. http://dx.doi.org/10.1093/mnras/242.3.395.

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49

Bignami, Giovanni F. "Gamma rays from galactic 26A1". Nature 325, n. 6102 (gennaio 1987): 302–3. http://dx.doi.org/10.1038/325302a0.

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50

Gupta, Nayantara. "Gamma rays from Centaurus A". Journal of Cosmology and Astroparticle Physics 2008, n. 06 (20 giugno 2008): 022. http://dx.doi.org/10.1088/1475-7516/2008/06/022.

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