Journal articles: 'UV photon detector'

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Ambily, S., Mayuresh Sarpotdar, Joice Mathew, A. G. Sreejith, K. Nirmal, Ajin Prakash, Margarita Safonova, and Jayant Murthy. "Development of Data Acquisition Methods for an FPGA-Based Photon Counting Detector." Journal of Astronomical Instrumentation 06, no. 01 (March 2017): 1750002. http://dx.doi.org/10.1142/s2251171717500027.

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MCP-based detectors are widely used in the ultraviolet (UV) region due to their low noise levels, high sensitivity and good spatial and temporal resolution. We have developed a compact near-UV (NUV) detector for high-altitude balloon and space flights, using off-the-shelf MCP, CMOS sensor, and optics. The detector is designed to be capable of working in the direct frame transfer mode as well in the photon counting mode for single photon event detection. The identification and centroiding of each photon event are done using an FPGA-based data acquisition and real-time processing system. In this paper, we discuss various algorithms and methods used in both operating modes, as well as their implementation on the hardware.

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Melai, Joost, Alexey Lyashenko, Amos Breskin, Harry van der Graaf, Jan Timmermans, Jan Visschers, Cora Salm, and Jurriaan Schmitz. "An integrated Micromegas UV-photon detector." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 633 (May 2011): S194—S197. http://dx.doi.org/10.1016/j.nima.2010.06.165.

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Kuleshov, D. O., V. A. Simonyan, A. A. Bogdanov, E. E. Kholupenko, Yu V. Tuboltsev, Yu V. Chichagov, and A. M. Krassilchtchikov. "Measurement of the photon detection efficiency of silicon photomultipliers for the new detector cluster of the Cherenkov gamma-ray telescope TAIGA-IACT equipped with UV filters." Journal of Physics: Conference Series 2103, no. 1 (November 1, 2021): 012036. http://dx.doi.org/10.1088/1742-6596/2103/1/012036.

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Abstract This study was devoted to measurements of the UV-range photon detection efficiency (PDE) of OnSemi MicroFJ SiPM detectors use together with custom UV filters and of the transmission coefficient of these filters at 277 nm. The final goal of these measurements was to determine feasibility of the filters for the new detector cluster of the TAIGA-IACT telescope. PicoQuant PLS-270 UV source emitting pulses at 277 nm was calibrated. The obtained dependences of the registered radiation power on the distance between the emission source and the reference detector are well approximated by the inverse square function, hence no significant scattering or absorption influenced the PDE measurements. The dependences of the number of detected photons on the distance between the source and the detector were obtained. These dependencies are also well approximated by the inverse square function. The PDE of SiPM MicroFJ-60035 detector was measured at the level of 10.0 ± 0.7%. The transmission coefficients of the considered set of filters at the wavelength of 277 nm were also obtained. The SL 240-300 filter has a sufficiently high transmission coefficient and it is advisable to use it as a bandpass ultraviolet filter in the new detector cluster of the TAIGA-IACT telescope; the SL 290-590 filter absorbs ultraviolet light quite well and is applicable in the visible range.

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Drazdys, R., J. Jukonis, A. Skrebutėnas, V. Vansevičius, and G. Vilkaitis. "A Bidimensional Photon-counting Microchannel Plate Detector Using a Wedge and Strip Anode." International Astronomical Union Colloquium 136 (1993): 169–71. http://dx.doi.org/10.1017/s0252921100007521.

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AbstractA photon-counting detector with a 45 mm diameter active area has been developed using a microchannel plate (MCP) and the wedge and strip readout system. The detector uses a UV transparent glass input window proximity coupled to a stack of MCP. Quantum efficiency (QE) of the detector photo-cathode is ~ 20%. The resolution of ~ 60 μm FWHM at a gain of 5.107 has been achieved.

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Hamar, G., and D. Varga. "TCPD, a TGEM based hybrid UV photon detector." Journal of Instrumentation 8, no. 12 (December 23, 2013): C12038. http://dx.doi.org/10.1088/1748-0221/8/12/c12038.

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BU Shao-fang, 卜绍芳, 尼启良 NI Qi-liang, 何玲平 HE Ling-ping, 张宏吉 ZHANG Hong-ji, and 刘世界 LIU Shi-jie. "Microchannel plate photon counting detector in UV range." Chinese Journal of Optics and Applied Optics 5, no. 3 (2012): 302–9. http://dx.doi.org/10.3788/co.20120503.0302.

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Bidault, J. M., P. Fonte, T. Francke, P. Galy, V. Peskov, and I. Rodionov. "A Novel UV Photon Detector with Resistive Electrodes." Nuclear Physics B - Proceedings Supplements 158 (August 2006): 199–203. http://dx.doi.org/10.1016/j.nuclphysbps.2006.07.009.

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ABBAS, Istabrak A. Abed, and Omar A. IBRAHIM. "PREPARATION THE UV PHOTOCONDUCTIVE DETECTOR BY TPD:ZNO NPS BLEND." MINAR International Journal of Applied Sciences and Technology 03, no. 02 (June 1, 2021): 183–90. http://dx.doi.org/10.47832/2717-8234.2-3.23.

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Physical properties includes Hall measurement , UV NPs, (I –V Measurements) and (Electro - optic properties IPCE) of ZnO NPs:TPD :PMMA Photo detectors deposited on P Si by two methods ( phase segregation method and drop casting method) and compression with properties of the Presence of polymers (PMMA TPD) were distinguished using I-V Measurement by figures of merit .IPCE measures the absorption of the prepared photo detector in different wavelengths. This can be done according to the photon absorption of the monochromatic light of the incident radiation with a wavelength of 570 nm and 530 nm for the deposited film by phase segregation method and by drop casting method at current efficacy 0.09% and 0.56% respectively and for only polymers is 0.19% . In I-V characterization the photoconductive gain has improved by the method of deposition of device by drop casting method, then ZnO NPs embedded in TPD:PMMA polymer highly improved the photoconductive gain from 34 to 77 by phase segregation method and to 88 by drop casting method , The responsivity was increased from to 3.6*10-6 A/W for films prepared by phase segregation method to 8.4*10-6 A/W for films prepared by drop casting method and response time from 8.2*10-6 μs. to 8.8*10-7 μs respectively.

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Finazzi, M., A. Bastianon, G. Chiaia, and F. Ciccacci. "High-sensitivity bandpass UV photon detector for inverse photoemission." Measurement Science and Technology 4, no. 2 (February 1, 1993): 234–36. http://dx.doi.org/10.1088/0957-0233/4/2/017.

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Scholze, Frank, Heike Henneken, Peter Kuschnerus,, Hans Rabus, Mathias Richter, and Gerhard Ulm. "High-accuracy detector calibration in the 3–1500 eV spectral range at the PTB radiometry laboratory." Journal of Synchrotron Radiation 5, no. 3 (May 1, 1998): 866–68. http://dx.doi.org/10.1107/s0909049597014076.

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State-of-the-art detector calibration in the UV/VUV and soft X-ray spectral ranges at the Physikalisch-Technische Bundesanstalt (PTB) is based on the primary detector standard SYRES, a cryogenic electrical substitution radiometer capable of measuring radiant power of a few µW. At the PTB radiometry laboratory at the synchrotron radiation facility BESSY, two dedicated beamlines are operated, providing monochromatic radiation of high spectral purity, high radiant power and tunable photon energy in the 3–1500 eV range. The spectral responsivity of detectors, e.g. photodiodes, can be measured with a relative uncertainty of about 1% by direct comparison with SYRES, as will be demonstrated for PtSi/Si and GaAsP/Au Schottky and silicon n-on-p photodiodes. The calibration of photon-counting detectors traceable to SYRES can by accomplished by exploiting the unique capability to scale the spectral photon flux over several orders of magnitude by changing the stored electron current. Calibrations of CCDs and photomultipliers are presented as examples.

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Breskin, A., A. Buzulutskov, R. Chechik, E. Shefer, and B. K. Singh. "Sealed gas UV-photon detector with a multi-GEM multiplier." IEEE Transactions on Nuclear Science 48, no. 3 (June 2001): 417–20. http://dx.doi.org/10.1109/23.940091.

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Ho, Ching-Hwa, and Yi-Ping Wang. "NIR and UV enhanced photon detector made by diindium trichalcogenides." Optical Materials Express 3, no. 9 (August 21, 2013): 1420. http://dx.doi.org/10.1364/ome.3.001420.

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Lavigne, Claire, Antoine Roblin, and Stéphane Langlois. "Solar-blind UV imaging photon detector with automatic gain control." Measurement Science and Technology 13, no. 5 (March 28, 2002): 713–19. http://dx.doi.org/10.1088/0957-0233/13/5/309.

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Breskin, A., R. Chechik, and D. Sauvage. "A 3-stage gated UV-photon gaseous detector with optical imaging." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 286, no. 1-2 (January 1990): 251–61. http://dx.doi.org/10.1016/0168-9002(90)90229-y.

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15

Miyamoto, Hiroko, Matteo Battisti, Dario Barghini, Alexander Belov, Mario Bertaina, Marta Bianciotto, Francesca Bisconti, et al. "An end-to-end in-flight calibration of Mini-EUSO detector." EPJ Web of Conferences 283 (2023): 06017. http://dx.doi.org/10.1051/epjconf/202328306017.

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Mini-EUSO is a wide Field-of-View (FoV, 44°) telescope currently in operation from a nadir-facing UV-transparent window in the Russian Zvezda module on the International Space Station (ISS). It is the first detector of the JEM-EUSO program deployed on the ISS, launched in August 2019. The main goal of Mini-EUSO is to measure the UV emissions from the ground and atmosphere, using an orbital platform. Mini-EUSO is mainly sensitive in the 290–430 nm bandwidth. Light is focused by a system of two Fresnel lenses of 25 cm diameter each on the Photo-Detector-Module (PDM), which consists of an array of 36 Multi-Anode Photomultiplier Tubes (MAPMTs), arranged in blocks of 2 × 2 called Elementary Cells (ECs), for a total of 2304 pixels working in photon counting mode, in three different time resolutions of 2.5 µs (defined as 1 Gate Time Unit, GTU), 320 µs and 40.96 ms operating in parallel. In the longest time scale, the data is continuously acquired to monitor the UV emission of the Earth. It is best suited for the observation of ground sources and therefore has been used for the observational campaigns of the ground-based UV flasher in order to perform an end-to-end calibration of Mini-EUSO. In this contribution, the assembled UV flasher, the operation of the field campaign and the analysis of the obtained data are presented. The result is compared with the overall effi ciency computed from the expectations which takes into account the atmospheric attenuation and the parametrisation of different effects such as the optics effi ciency, the MAPMT detection effi ciency, BG3 filter transmittance and the transparency of the ISS window.

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Zimmer, C. M., K. T. Kallis, and F. J. Giebel. "Micro-structured electron accelerator for the mobile gas ionization sensor technology." Journal of Sensors and Sensor Systems 4, no. 1 (April 14, 2015): 151–57. http://dx.doi.org/10.5194/jsss-4-151-2015.

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Abstract. Mobile and economically priced gas monitoring and warning systems will become increasingly important for civil security, such as in fire brigade operations in undefined hazardous environments (Daum et al., 2006). Normally, photoionization detectors (PIDs) are used for the detection of gases. Hereby, the principle is based upon the ionization of the measured gas by photons, which are generated by a high-energetic gas discharge lamp with energy of 10–11 eV. Besides the detrimental unspecific gas detection because of the ionization of all gases with ionization potential (IP) below the provided photon energy, sensors also have a short lifetime combined with a high cost (http://www.intlsensor.com/pdf/photoionization.pdf). This can be remedied by the concept of an electronic supported photoionization detector (ePID; Zimmer et al., 2012) consisting of a durable UV-LED with an above-positioned electron accelerator chip manufactured on a glass substrate by planar technology. Photoelectrons are extracted by UV illumination out of the bottom electrode and will be accelerated to an energy matching the ionization potential of the gas by a downstream acceleration grid. Thereby, the stable honeycomb-structured grid acts as a porous separator between the evacuated electron acceleration path due to nm scaling and the ionization area of the detector. To enhance the emitting area yielding a higher photoelectron current, the grid structure almost levitates, realized by the use of compatible planar technological processes such as reactive ion etching (RIE) and isotropic wet etching of sacrificial layers, which will be explained in detail in this paper. Furthermore, the tunability of the grid's acceleration voltage would enable a substance-specific determination of the gas composition, where the ionization of the analytes is clearly performed by photoelectrons instead of photons.

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O'Brien, Kieran, Ben Mazin, Sean McHugh, Seth Meeker, and Bruce Bumble. "ARCONS: a Highly Multiplexed Superconducting UV-to-Near-IR Camera." Proceedings of the International Astronomical Union 7, S285 (September 2011): 385–88. http://dx.doi.org/10.1017/s1743921312001159.

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AbstractARCONS, the Array Camera for Optical to Near-infrared Spectrophotometry, was recently commissioned at the coudé focus of the 200-inch Hale Telescope at the Palomar Observatory. At the heart of this unique instrument is a 1024-pixel Microwave Kinetic Inductance Detector (MKID), exploiting the Kinetic Inductance effect to measure the energy of the incoming photon to better than several percent. The ground-breaking instrument is lens-coupled with a pixel scale of 0″.23/pixel, each pixel recording the arrival time (< 2 μ sec) and energy of a photon (~10%) in the optical to near-IR (0.4–1.1 microns) range. The scientific objectives of the instrument include the rapid follow-up and classification of transient phenomena.

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Szécsényi-Nagy, Gábor. "Use of CCDs in Schmidt Telescopes for the Investigation of Hα Emission of Flare Stars." International Astronomical Union Colloquium 148 (1995): 60–64. http://dx.doi.org/10.1017/s0252921100021710.

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AbstractThe use of Schmidt telescopes in their traditional mode for the detection of stellar flares and for the UV and PG photometry of these stars proved to be very productive. The fast optical system and reliable sensitivity of modern photographic emulsions resulted in a photometric time-resolution of several minutes even in the case of distant objects. One of the most important characteristics of flare stars may be the tendency for coexistence with more massive and more luminous member stars of young stellar aggregates (mainly open clusters). Although the vast majority of flare stars discovered seem to belong to clusters, a great many of them are neighbours of our sun. These can be investigated in depth because a sufficient number of their photons can be collected and recorded in narrow photometric bands or even in spectra of good resolution. The direct comparison of solar vicinity flare stars with flare-active members of distant clusters has been almost impossible. However recent developments in silicon-based photon-detecting technology offer the advantage of incredibly high detector quantum efficiency (DQE) in many spectral regions where photographic materials never reached an acceptable level. Hα emission is one of the most characteristic features of flare stars, and the wavelength of Hα photons fits extremely well with the peak of the spectral sensitivity curves of silicon photon detectors. CCD chips placed in the focal surface of Schmidt telescopes seem to be very promising for the future investigation of Hα emission of flare stars.

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Dangendorf, V., A. Breskin, R. Chechik, and H. Schmidt-Böcking. "A gas-filled UV-photon detector with CsI photocathode for the detection of Xe light." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 289, no. 1-2 (April 1990): 322–24. http://dx.doi.org/10.1016/0168-9002(90)90276-c.

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Peskov, V., M. Cortesi, R. Chechik, and A. Breskin. "Further evaluation of a THGEM UV-photon detector for RICH – comparison with MWPC." Journal of Instrumentation 5, no. 11 (November 22, 2010): P11004. http://dx.doi.org/10.1088/1748-0221/5/11/p11004.

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Bertacco, R., L. Duo, P. Vavassori, and L. Braicovich. "A high-efficiency photon detector for parallel acquisition of UV inverse photoemission spectroscopy." Measurement Science and Technology 5, no. 8 (August 1, 1994): 1015–17. http://dx.doi.org/10.1088/0957-0233/5/8/024.

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Liu Yong-An, Yan Qiu-Rong, Sheng Li-Zhi, Zhao Fei-Fei, Hu Hui-Jun, and Zhao Bao-Sheng. "Influence of charge cloud size on performance of UV photon-counting imaging detector." Acta Physica Sinica 60, no. 4 (2011): 048501. http://dx.doi.org/10.7498/aps.60.048501.

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Zimmer, C. M., C. Asbeck, D. Lützenkirchen-Hecht, P. Glösekötter, and K. T. Kallis. "Backside Illumination of an Electronic Photo Ionization Detector Realized by UV Transparent Thin Films." Journal of Nano Research 25 (October 2013): 55–60. http://dx.doi.org/10.4028/www.scientific.net/jnanor.25.55.

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LaB6/ITO films were prepared by magnetron sputtering technique on borosilicate glass substrates. The transmittance of ITO and LaB6/ITO films was analyzed by using UV/VIS spectrophotometer, whereby the sheet resistance of the ITO films was measured by four point probes. The effect of temperature and post-annealing processes on ITO film properties optimizing UV transparency and sheet resistance were investigated in detail. ITO films with an optimized thickness of 31 nm exhibited a low sheet resistance of 64 Ω/sq and a high ultraviolet transmittance of 81% at a wavelength of 365 nm. The additional LaB6 layer controls the UV transmittance behavior of the bilayer structure of LaB6/ITO by improving the photon absorption with thicker LaB6 films. The work function of LaB6 (32 nm)/ITO films with a value of 4.98 eV was measured by ultraviolet photoelectron spectroscopy (UPS).

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Hamar, M., V. Michálek, and A. Pathak. "Non-classical Signature of Parametric Fluorescence and its Application in Metrology." Measurement Science Review 14, no. 4 (August 1, 2014): 227–36. http://dx.doi.org/10.2478/msr-2014-0031.

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Abstract The article provides a short theoretical background of what the non-classical light means. We applied the criterion for the existence of non-classical effects derived by C.T. Lee on parametric fluorescence. The criterion was originally derived for the study of two light beams with one mode per beam. We checked if the criterion is still working for two multimode beams of parametric down-conversion through numerical simulations. The theoretical results were tested by measurement of photon number statistics of twin beams emitted by nonlinear BBO crystal pumped by intense femtoseconds UV pulse. We used ICCD camera as the detector of photons in both beams. It appears that the criterion can be used for the measurement of the quantum efficiencies of the ICCD cameras.

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J.Höhne, M. Altmann, G. Angloher, M. Bühler, F. v. Feilitzsch, T. Frank, P. Hettl, et al. "Cryogenic Microcalorimeters for High Resolution Energy Dispersive X-Ray Spectrometry." Microscopy and Microanalysis 5, S2 (August 1999): 604–5. http://dx.doi.org/10.1017/s1431927600016342.

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AbstractCryogenic detectors with excellent energy resolution and low energy threshold far beyond the level of semiconducting detectors open a variety of new. applications in physics including search for Dark Matter in the universe [2], neutrino physics [3], and IR-, UV- and X-ray astrophysics [4, 9]. Interdisciplinary fields where cryogenic detectors have already shown promising results are the detection of biomolecules [5] and X-ray spectroscopy at synchrotron beam lines [6] and in scanning electron microscopes (SEMs) [7]. For both, astrophysical and analytical use, the development of high resolution microcalorimeters based on iridium/gold phase transition thermometers and aluminum tunnel junctions for use in a compact and universal detector system was initiated.Our cryogenic microcalorimeters consist of an absorber, a temperature sensor and a weak coupling to a heat sink. An X-ray photon interacts with the absorber and raises its temperature. The sensor measures the temperature increase and the system then, mediated by the coupling, relaxes back to its operating temperature.

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Putignano, O., G. Croci, A. Muraro, S. Cancelli, F. Caruggi, G. Gorini, G. Grosso, et al. "Conceptual design of a GEM (gas electron multiplier) based gas Cherenkov detector for measurement of 17 MeV gamma rays from T(D, γ)⁵He in magnetic confinement fusion plasmas." Review of Scientific Instruments 94, no. 1 (January 1, 2023): 013501. http://dx.doi.org/10.1063/5.0101761.

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The only method for assessing the fusion power throughput of a deuterium–tritium (DT) reactor presently relies on determining the absolute number of 14 MeV neutrons produced in the DT plasma. An independent method, developed and investigated during the recent DT campaign at the Joint European Torus, is based on the absolute counting of 17 MeV gamma rays produced by the competing T(D, γ)5He reaction that features a very weak branching ratio (about 3–6 × 10−6) when compared to the main T(D, n)4He reaction. The state-of-the-art spectrometer used for gamma-ray measurements in magnetic confinement fusion plasmas is LaBr3(Ce) scintillator detectors, although they require significant neutron shielding to extract a relatively weak gamma-ray signal from a much more abundant neutron field. A better approach relies on a gamma-ray detector that is intrinsically insensitive to neutrons. We have advanced the design of a gamma-ray counter based on the Cherenkov effect for gamma-rays whose energy exceeds 11 MeV, optimized to work in the neutron-rich environment of a steady-state, magnetically confined fusion plasma device. The gamma-rays interact with an aluminum window and extract electrons that move into the radiator emitting photons via the Cherenkov effect. Since the Cherenkov light consists of few photons (25 on average) in the far UV band (100–200 nm), a pre-amplifier is required to transport the photons to the neutron-shielded location, which may be a few meters away, where the readout elements of the detector, either a silicon or standard photomultiplier tube, are placed. The present work focuses on the development of a scintillating GEM (Gas Electron Multiplier) based pre-amplifier that acts as a Cherenkov photon pre-amplifier and wavelength shifter. This paper presents the result of a set of Garfield++ simulations developed to find the optimal GEM working parameters. A photon gain of 100 is obtained by biasing a single GEM foil to 1 kV.

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Sudjai, T., J. S. Lapington, and S. A. Leach. "Picosecond imaging at high spatial resolution using TOFPET2 AISC v2d and microchannel plate detector." Journal of Instrumentation 17, no. 09 (September 1, 2022): C09016. http://dx.doi.org/10.1088/1748-0221/17/09/c09016.

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Abstract Microchannel plate-based detectors provide advantages over their solid-state counterparts for applications where a combination of virtually zero noise photon-counting, large format, short wavelength sensitivity with high resolution timing and imaging are required. Solar-blind applications, Cherenkov detectors for high energy physics, and UV astronomy are such fields. The application to Cherenkov detection is particularly demanding, requiring time resolution below 100 picoseconds combined with imaging and high throughput. This requires the readout to combine high spatial and temporal event resolution at high rates necessitating a parallel readout approach. We describe a readout design comprising a pixellated readout array instrumented using multi-channel fast timing electronics and incorporating charge centroiding to achieve sub-pixel spatial resolution. We present experimental results of the relationship between time-over-threshold and signal amplitude and a centroiding image obtained with an MCP detector using a pixellated readout geometry. The readout was optimised for a fast electronics implementation based on the TOFPET system, a multi-channel all-in-one ASIC originally designed for time-of-flight PET using silicon photomultipliers.

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Bastian-Querner, Benjamin, Lucas S. Binn, Sebastian Böser, Jannes Brostean-Kaiser, Dustin Hebecker, Klaus Helbing, Timo Karg, et al. "The Wavelength-Shifting Optical Module." Sensors 22, no. 4 (February 11, 2022): 1385. http://dx.doi.org/10.3390/s22041385.

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The Wavelength-shifting Optical Module (WOM) is a novel photosensor concept for the instrumentation of large detector volumes with single-photon sensitivity. The key objective is to improve the signal-to-noise ratio, which is achieved by decoupling the photosensitive area of a sensor from the cathode area of its photomultiplier tube (PMT). The WOM consists of a transparent tube with two PMTs attached to its ends. The tube is coated with wavelength-shifting paint that absorbs ultraviolet photons with nearly 100% efficiency. Depending on the environment, e.g., air (ice), up to 73% (41%) of the subsequently emitted optical photons can be captured by total internal reflection and propagate towards the PMTs, where they are recorded. The optical properties of the paint, the geometry of the tube, and the coupling of the tube to the PMTs have been optimized for maximal sensitivity based on theoretical derivations and experimental evaluations. Prototypes were built to demonstrate the technique and to develop a reproducible construction process. Important measurable characteristics of the WOM are the wavelength-dependent effective area, the transit time spread of detected photons, and the signal-to-noise ratio. The WOM outperforms bare PMTs, especially with respect to the low signal-to-noise ratio with an increase of a factor up to 8.9 in air (5.2 in ice). Since the gain in sensitivity is mostly in the UV regime, the WOM is an ideal sensor for Cherenkov and scintillation detectors.

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Baishali, G., V. Radhakrishna, V. Koushal, K. Rakhee, and K. Rajanna. "Performance study of a cesium iodide photocathode-based UV photon detector in Ar/CH_4 mixture." Photonics Research 2, no. 3 (May 30, 2014): 92. http://dx.doi.org/10.1364/prj.2.000092.

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Niemela, V. S., S. R. Heathcote, and W. G. Weller. "A Search for High Excitation Nebulae Around Wolf-Rayet Stars in the Magellanic Clouds." Symposium - International Astronomical Union 143 (1991): 425–26. http://dx.doi.org/10.1017/s0074180900045575.

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We have serendipitously discovered that the WN+O binary Br 40a in the LMC is surrounded by a remarkable high excitation nebula, showing extended, narrow emission lines of HeII. This prompted us to make a systematic search for similar high excitation nebulae around other WR stars in the Magellanic Clouds. This survey revealed a second even more extreme example surrounding the WN+O binary AB-7 in the SMC, and one other marginal detection AB-5 (SMC). The detection of nebular HeII emission implies that these WN stars emit a much harder UV spectrum than is traditionally expected. For each of these nebulae we have taken narrow band CCD images at the CTIO 0.9-m telescope, and have obtained spectrophotometry with the 2D-Frutti photon counting detector on the CTIO 1.0-m telescope.

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He, Li Ping, Yu Fang, Shu Fan Chen, Xuan Luo, Zhi Jun Wei, Dong Xiao Liu, Lin Zhang, and Xin Li. "Measurement System of Decay Time for Liquid Scintillator." Applied Mechanics and Materials 513-517 (February 2014): 4285–86. http://dx.doi.org/10.4028/www.scientific.net/amm.513-517.4285.

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The fluorescence lifetime of the molecular excited states in the liquid scintillator determines the pulse shape of the events in a detector. The fluorescence decay times of the mixtures could be measured by UV light excitation, or via ionizing particles. Both of the setups are based on the time-correlated single photon technique. In this paper we described a setup in detail for testing the fluorescence lifetime under ionizing particle to render the relatively weak neutron or ion signals detectable. In addition, we presented the time resolution of system for the setup.

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Lampton, M., S. Bowyer, and J. M. Deharveng. "Imaging Large– and Small–Scale Structures of the Far Ultraviolet Background with the Faust Instrument." Symposium - International Astronomical Union 139 (1990): 449–52. http://dx.doi.org/10.1017/s0074180900241259.

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The FAUST telescope is an ultraviolet survey instrument that features a wide 8° field of view, ~1′ angular resolution, and a photon counting detector. Operating in the 1400–1800 Å band, it will be sufficiently sensitive to detect blue mv =17 objects in a single 20 minute night. The instrument is part of the ATLAS-1 shuttle mission, presently scheduled for flight in May 1991. A substantial number of high galactic latitude fields will be investigated, with particular emphasis on studies of the origin of the diffuse far UV background.

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Liu, Geng, Liang Yao, Ying Liu, Rongdun Hong, Ruijun Zhang, and Feng Zhang. "Study on SiC UV/EUV Coaxial Photodetector." Journal of Physics: Conference Series 2549, no. 1 (July 1, 2023): 012014. http://dx.doi.org/10.1088/1742-6596/2549/1/012014.

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Abstract In this paper, a novel 4H-SiC coaxial p-i-n ultraviolet photodetector with intense photon absorption and high quantum efficiency is studied. The spectral response and electric field distribution of the detector are calculated by TCAD software. The results showed that the innovative 4H-SiC ultraviolet coaxial p-i-n photodetector has a spectral response peak of 0.1998 A/W at 260 nm illumination wavelength and has more than twice response higher than the traditional 4H-SiC p-i-n photodetector, when the illumination wavelength is under 270 nm. The quantum efficiency of the coaxial photodetector reaches 95.3%. Moreover, in the wavelength range of EUV, the 4H-SiC ultraviolet coaxial photodetector shows a relatively high response, while the response is barely observed for the traditional 4H-SiC p-i-n photodetector. For the large area coaxial p-i-n photodetector, the problem of laterally undepleted i layer can be solved by multiple P+-type implanation. The new structure significantly enhances the rate of incident light absorption, prevents the light absorption of the conventional metal electrode and P+ layer, and provides an innovative approach for the construction of ultraviolet photodetectors in the future.

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Kozlov, A., I. Ravinovich, L. Shekhtman, Z. Fraenkel, M. Inuzuka, and I. Tserruya. "Development of a triple GEM UV-photon detector operated in pure CF4 for the PHENIX experiment." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 523, no. 3 (May 2004): 345–54. http://dx.doi.org/10.1016/j.nima.2003.12.018.

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Orlov, D. A., R. Glazenborg, R. Ortega, and E. Kernen. "UV/visible high-sensitivity MCP-PMT single-photon GHz counting detector for long-range lidar instrumentations." CEAS Space Journal 11, no. 4 (June 19, 2019): 405–11. http://dx.doi.org/10.1007/s12567-019-00260-0.

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Seljak, A., H. S. Cumming, G. Varner, J. Vallerga, R. Raffanti, and V. Virta. "Prototype readout system for a multi Mpixels UV single-photon imaging detector capable of space flight operation." Journal of Instrumentation 13, no. 02 (February 7, 2018): T02003. http://dx.doi.org/10.1088/1748-0221/13/02/t02003.

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Li, Gaoming, Xiaolong Zhao, Xiangwei Jia, Shuangqing Li, and Yongning He. "Characterization of Impact Ionization Coefficient of ZnO Based on a p-Si/i-ZnO/n-AZO Avalanche Photodiode." Micromachines 11, no. 8 (July 30, 2020): 740. http://dx.doi.org/10.3390/mi11080740.

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The avalanche photodiode is a highly sensitive photon detector with wide applications in optical communication and single photon detection. ZnO is a promising wide band gap material to realize a UV avalanche photodiode (APD). However, the lack of p-type doping, the strong self-compensation effect, and the scarcity of data on the ionization coefficients restrain the development and application of ZnO APD. Furthermore, ZnO APD has been seldom reported before. In this work, we employed a p-Si/i-ZnO/n-AZO structure to successfully realize electron avalanche multiplication. Based on this structure, we investigated the band structure, field profile, Current–Voltage (I-V) characteristics, and avalanche gain. To examine the influence of the width of the i-ZnO layer on the performance, we changed the i-ZnO layer thickness to 250, 500, and 750 nm. The measured breakdown voltages agree well with the corresponding threshold electric field strengths that we calculated. The agreement between the experimental data and calculated results supports our analysis. Finally, we provide data on the impact ionization coefficients of electrons for ZnO along the (001) direction, which is of great significance in designing high-performance low excess noise ZnO APD. Our work lays a foundation to realize a high-performance ZnO-based avalanche device.

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Seljak, A., H. S. Cumming, G. Varner, J. Vallerga, R. Raffanti, and V. Virta. "A fast, low power and low noise charge sensitive amplifier ASIC for a UV imaging single photon detector." Journal of Instrumentation 12, no. 04 (April 19, 2017): T04007. http://dx.doi.org/10.1088/1748-0221/12/04/t04007.

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Roesler, F. L., J. Harlander, and R. J. Reynolds. "An Observatory for Mapping the Far UV Diffuse Galactic Emission Line Background." International Astronomical Union Colloquium 123 (1990): 481–86. http://dx.doi.org/10.1017/s0252921100077502.

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AbstractA new instrumental concept for interference spectroscopy called Spatial Heterodyne Spectroscopy (SHS) is described. This instrument as currently demonstrated could provide important information on the structure, excitation, and dynamics of the ≃ 105 K component of the interstellar medium by providing velocity-resolved (20 km s−1) maps of the faint FUV emission line background over a hemisphere of the sky within a 5-6 year observation period. We are currently studying concepts expected to reduce this time by at least an order of magnitude.In the SHS technique, an all-reflection dispersive interferometer produces a Fourier transform of the spectrum as two-dimensional spatial frequencies on an imaging detector. The system does not require scanning, and measures its own internal alignment state. Although the system suffers the conventional Fourier transform multiplex disadvantage associated with the photon noise in the background FUV continuum, we estimate that for a broad-band survey Spatial Heterodyne Spectroscopy as currently demonstrated can provide 4-5 fold gains over practical grating spectrometers of similar dimensions and spatial and spectral resolution. Field widened methods currently being studied promise additional gains of two orders of magnitude.

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Klimov, Pavel, Gali Garipov, Boris Khrenov, Violetta Morozenko, Vera Barinova, Vitaly Bogomolov, Margarita Kaznacheeva, Mikhail Panasyuk, Kirill Saleev, and Sergey Svertilov. "Vernov Satellite Data of Transient Atmospheric Events." Journal of Applied Meteorology and Climatology 56, no. 8 (August 2017): 2189–201. http://dx.doi.org/10.1175/jamc-d-16-0309.1.

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AbstractData on transient atmospheric events (TAEs) were obtained from the Vernov satellite and are presented in this paper. The data are considered in conjunction with previous data obtained by the Universitetsky-Tatiana-1 and Universitetsky-Tatiana-2 satellites. The larger volume of stored scientific data in the Vernov mission and its advanced ultraviolet (UV) and red–infrared (R–IR) radiation detector (DUV) measurements allowed improved TAE-distribution data to be obtained over a wide range of photon numbers. The difference between features of luminous transients and “dim” transients, measured by the Universitetsky-Tatiana-2 satellite, is confirmed by Vernov’s data. There are also interesting dim UV events with no R–IR radiation. Such events are expected to be deep in the atmosphere at the level of thunderstorm clouds. They might be radiated by electric discharges of less power than lightning; in fact, at the preliminary stage of lightning. The observation of repeating dim TAEs in various time intervals, starting from tens of milliseconds and up to minutes, indicates that thunderstorm electric activity is much more variable than pure lightning strikes.

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Bertaina, Mario Edoardo, Dario Barghini, Matteo Battisti, Alexander Belov, Marta Bianciotto, Francesca Bisconti, Carl Blaksley, et al. "Implications of Mini-EUSO measurements for a space-based observation of UHECRs." EPJ Web of Conferences 283 (2023): 06008. http://dx.doi.org/10.1051/epjconf/202328306008.

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Mini-EUSO is the first mission of the JEM-EUSO program on board the International Space Station. It was launched in 2019 and it is currently located in the Russian section (Zvezda module) of the station and viewing our planet from a nadir-facing UV-transparent window. The instrument is based on the concept of the original JEM-EUSO mission and consists of an optical system employing two Fresnel lenses and a focal surface composed of 36 Multi-Anode Photomultiplier tubes, 64 channels each, for a total of 2304 channels with single photon counting sensitivity and an overall field of view of 44° × 44°. Mini-EUSO can map the night-time Earth in the near UV range (predominantly between 290 nm and 430 nm), with a spatial resolution of about 6.3 km and different temporal resolutions of 2.5 µ, 320 µs and 41 ms. Mini-EUSO observations are extremely important to better assess the potential of a space-based detector in studying Ultra-High Energy Cosmic Rays (UHECRs) such as K-EUSO and POEMMA. In this contribution we focus the attention on UV measurements, the observation of clouds and of certain categories of events that Mini-EUSO triggers with the shortest temporal resolution. We place them in the context of UHECR observations from space, namely the estimation of exposure and sensitivity to Extensive Air Showers.

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Kelly, Lisa A., John G. Trunk, Krzysztof Polewski, and John C. Sutherland. "Simultaneous resolution of spectral and temporal properties of UV and visible fluorescence using single‐photon counting with a position‐sensitive detector." Review of Scientific Instruments 66, no. 2 (February 1995): 1496–98. http://dx.doi.org/10.1063/1.1145953.

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Riethmüller, T. L., and S. K. Solanki. "The potential of many-line inversions of photospheric spectropolarimetric data in the visible and near UV." Astronomy & Astrophysics 622 (January 24, 2019): A36. http://dx.doi.org/10.1051/0004-6361/201833379.

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Our knowledge of the lower solar atmosphere is mainly obtained from spectropolarimetric observations, which are often carried out in the red or infrared spectral range and almost always cover only a single or a few spectral lines. Here we compare the quality of Stokes inversions of only a few spectral lines with many-line inversions. In connection with this, we have also investigated the feasibility of spectropolarimetry in the short-wavelength range, 3000 Å−4300 Å, where the line density but also the photon noise are considerably higher than in the red, so that many-line inversions could be particularly attractive in that wavelength range. This is also timely because this wavelength range will be the focus of a new spectropolarimeter in the third science flight of the balloon-borne solar observatory SUNRISE. For an ensemble of state-of-the-art magneto-hydrodynamical atmospheres we synthesize exemplarily spectral regions around 3140 Å (containing 371 identified spectral lines), around 4080 Å (328 lines), and around 6302 Å (110 lines). The spectral coverage is chosen such that at a spectral resolving power of 150 000 the spectra can be recorded by a 2K × 2K detector. The synthetic Stokes profiles are degraded with a typical photon noise and afterward inverted. The atmospheric parameters of the inversion of noisy profiles are compared with the inversion of noise-free spectra. We find that significantly more information can be obtained from many-line inversions than from a traditionally used inversion of only a few spectral lines. We further find that information on the upper photosphere can be significantly more reliably obtained at short wavelengths. In the mid and lower photosphere, the many-line approach at 4080 Å provides equally good results as the many-line approach at 6302 Å for the magnetic field strength and the line-of-sight (LOS) velocity, while the temperature determination is even more precise by a factor of three. We conclude from our results that many-line spectropolarimetry should be the preferred option in the future, and in particular at short wavelengths it offers a high potential in solar physics.

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Bisconti, F., H. Miyamoto, D. Barghini, M. Battisti, A. Belov, M. E. Bertaina, S. Blin-Bondil, et al. "Pre-flight qualification tests of the Mini-EUSO telescope engineering model." Experimental Astronomy 53, no. 1 (October 20, 2021): 133–58. http://dx.doi.org/10.1007/s10686-021-09805-w.

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AbstractMini-EUSO is part of the JEM-EUSO program and operates on board the International Space Station (ISS). It is a UV-telescope with single-photon counting capability looking at nighttime downwards to the Earth through a nadir-facing UV-transparent window. As part of the pre-flight tests, the Mini-EUSO engineering model, a telescope with 1/9 of the original focal surface and a lens of 2.5 cm diameter, has been built and tested. Tests of the Mini-EUSO engineering model have been made in laboratory and in open-sky conditions. Laboratory tests have been performed at the TurLab facility, located at the Physics Department of the University of Turin, equipped with a rotating tank containing different types of materials and light sources. In this way, the configuration for the observation of the Earth from space was emulated, including the Mini-EUSO trigger schemes. In addition to the qualification and calibration tests, the Mini-EUSO engineering model has also been used to evaluate the possibility of using a JEM-EUSO-type detector for applications such as observation of space debris. Furthermore, observations in open-sky conditions allowed the studies of natural light sources such as stars, meteors, planets, and artificial light sources such as airplanes, satellites reflecting the sunlight, and city lights. Most of these targets could be detected also with Mini-EUSO. In this paper, the tests in laboratory and in open-sky conditions are reported, as well as the obtained results. In addition, the contribution that such tests provided to foresee and improve the performance of Mini-EUSO on board the ISS is discussed.

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KUZANYAN, A., V. KUZANYAN, G. BADALYAN, V. NIKOGHOSYAN, M. KONOVALOV, V. GURIN, U. BURKHARDT, and Y. GRIN. "X-RAY MICROANALYSIS OF CeB6 CRYSTALS WITH ROUGH SURFACES." International Journal of Modern Physics: Conference Series 15 (January 2012): 67–75. http://dx.doi.org/10.1142/s2010194512006976.

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The influence of surface roughness on X-ray microanalysis results of cerium hexaboride crystals obtained by floating zone and flux methods is investigated. It is shown that the surface of crystals grown by the floating zone method is much rougher than the one of crystals obtained by the flux method. The correction one should apply to the experimental EDX results, depending on the standard arithmetic mean roughness amplitude R a and the inclination angle α of the studied surface area to the horizontal, i.e. the parameters determining the surface roughness, are calculated. The Ce / B ratio EDX data error due to surface roughness for a sample grown by the floating zone method is within the limits of ~2% and is less than for samples grown by the flux method. The obtained results have been used to determine the B / Ce ratio in the cerium hexaboride crystals with the purpose of developing the selection criteria of samples used in creating a single-photon thermoelectric detector of UV and X-ray ranges.

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Humayun, Qazi, Muhammad Kashif, and Uda Hashim. "Fabrication and characterization of a single-bridge nanorod between microgap electrodes." Microelectronics International 31, no. 2 (April 29, 2014): 104–7. http://dx.doi.org/10.1108/mi-12-2012-0084.

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Purpose – The purpose of this study was to investigate the performance of a single-bridge ZnO nanorod as a photodetector. Design/methodology/approach – The fabrication of the design sensor with ∼6-μm gap Schottky contacts and bridging of the ZnO nanorod were based on conventional photolithography and wet-etching technique. Prior to bridging, the ZnO nanorods were grown by the hydrothermal process. The 0.35 M seed solution was prepared by dissolving zinc acetate dihydrate in 2-methoxyethanol, and monoethanolamine, which acts as a stabilizer, was added drop-wise. Before starting the solution deposition, and oxide, titanium (Ti) and gold (Au) layer deposition, p-type (100) silicon substrate was cleaned with Radio Corporation of America (RCA1) and RCA2, followed by dipping in diluted hydrofluoric acid. The aged solution was dropped onto the surface of the Au microgap structure, using a spin coater at a spinning speed of 3,000 rpm for 45 seconds, and then dried at 300°C for 15 minutes, followed by annealing at 400°C for 1 hour. The hydrothermal growth was carried out in an aqueous solution of zinc nitrate hexahydrate (0.025 M) and hexamethyltetramine (0.025 M). Findings – In this study, ZnO nanorods were grown on a SiO2 substrate by the hydrothermal method. Microgap electrodes with ∼6-μm spacing were achieved by using the wet-etching process. After the growth process, an area-selective mask was utilized to reduce the number of rods between the nearby gap areas. The obtained single ZnO nanorod was tested for the UV-sensing application. The single ZnO nanorod photodetector exhibited a UV photoresponse, thereby indicating potential as a cost-effective UV detector. The response and recovery times of the fabricated device were 65 and 95 seconds, respectively. Structural analysis was captured using X-ray Diffraction (XRD), whereas surface morphology was determined using scanning electron microscopy. Originality/value – This paper demonstrates the effect of UV photon on a single-bridge ZnO nanorod between microgap electrodes.

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Hamdan, S. A., I. M. Ibrahim, and I. M. Ali. "Photodetector based on Rutile and Anatase TiO₂ nanostructures/n-Si Heterojunction." Journal of Physics: Conference Series 2114, no. 1 (December 1, 2021): 012025. http://dx.doi.org/10.1088/1742-6596/2114/1/012025.

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Abstract Rutile and anatase titanium dioxide TiO2 nanostructures has been prepared successfully by hydrothermal technique. Also Rutile and anatase TiO2/n-Si heterojunction detector (HJ) has been fabricated. Hall Effect measurements confirmed that prepared films are n-type. The optical absorption spectra showed the prepared films have peak absorption in UV region. TiO2/n-Si heterojunction had exhibited diode-like rectifying I-V behaviour in the dark as well as under the illumination. Ideality factor greater than 2 and rectification factor for Rutile TiO2/n-Si HJ is equal 32.0961 higher than anatase TiO2/n-Si HJ. Photodetetor based on rutile TiO2/n-Si HJ showed higher responsivity and incident photon-to-current efficiency (IPCE) than photodetector based on anatase TiO2/n-Si HJ. Photodetetor based on rutile TiO2/n-Si HJ has responsivity is 69.11Amp/W at 570 nm and IPCE is 21.2%at 370nm and 1.38% at 570nm. For the purpose of investigating the impacts of TiO2 crystal phase upon the performance of the device despite the fact that rutile has a lower band gap compared to anatase, rutile exhibits better photovoltaic activity due to its higher specific surface area.

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Kontos, Antonios, and Rainer Weiss. "Photon emission spectrum of ion pumps." Review of Scientific Instruments 94, no. 3 (March 1, 2023): 034503. http://dx.doi.org/10.1063/5.0138917.

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As the sensitivity of gravitational-wave detectors increases, new sources of noise appear. A potential source of noise may arise from charge accumulating on the mirrors of the experiment, the origin of which can be related to UV photons from the surroundings. In order to test one hypothesis, we measured the photon emission spectrum from a type of ion pump that is used in the experiment, an Agilent VacIon Plus 2500 l/s. We found that there is significant emission of UV photons above 5 eV, capable of knocking electrons off mirrors or surrounding surfaces and charging them. Photon emission measurements were taken as a function of gas pressure, ion-pump voltage setting, and type of pumped gas. The overall emission and shape of the measured photon spectrum are consistent with bremsstrahlung as the mechanism for the production of the photons.

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Ueno, Go, Atsuhiro Shimada, Eiki Yamashita, Kazuya Hasegawa, Takashi Kumasaka, Kyoko Shinzawa-Itoh, Shinya Yoshikawa, Tomitake Tsukihara, and Masaki Yamamoto. "Low-dose X-ray structure analysis of cytochrome c oxidase utilizing high-energy X-rays." Journal of Synchrotron Radiation 26, no. 4 (June 14, 2019): 912–21. http://dx.doi.org/10.1107/s1600577519006805.

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To investigate the effect of high-energy X-rays on site-specific radiation-damage, low-dose diffraction data were collected from radiation-sensitive crystals of the metal enzyme cytochrome c oxidase. Data were collected at the Structural Biology I beamline (BL41XU) at SPring-8, using 30 keV X-rays and a highly sensitive pixel array detector equipped with a cadmium telluride sensor. The experimental setup of continuous sample translation using multiple crystals allowed the average diffraction weighted dose per data set to be reduced to 58 kGy, and the resulting data revealed a ligand structure featuring an identical bond length to that in the damage-free structure determined using an X-ray free-electron laser. However, precise analysis of the residual density around the ligand structure refined with the synchrotron data showed the possibility of a small level of specific damage, which might have resulted from the accumulated dose of 58 kGy per data set. Further investigation of the photon-energy dependence of specific damage, as assessed by variations in UV-vis absorption spectra, was conducted using an on-line spectrometer at various energies ranging from 10 to 30 keV. No evidence was found for specific radiation damage being energy dependent.

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Zhang, Min, Zhenjiang Li, Yunfei Zhao, Zhaofeng Wu, Jun Zhang, Linyu Yang, Shuying Wang, and Shiqing Li. "Solar-Blind Photodetector Based on NaTaO3/TiO2 Composite Film with Enhanced Photoelectric Performance." Coatings 11, no. 10 (September 28, 2021): 1178. http://dx.doi.org/10.3390/coatings11101178.

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In this study, ultraviolet detectors based on NaTaO3/TiO2 were fabricated with enhanced detection performance towards solar-blind (200–280 nm) light. A TiO2 seed layer was introduced and served as a buffer layer between the fluorine tin oxide (FTO)-coated glass substrate and the TiO2 film, which increased the adhesion between them. The periodic stability and photoelectric characteristics of the detectors were studied and analyzed. The detectors showed a high performance when illuminated by 265 nm and 254 nm UV light. At −15 V bias, the dark current of the detector was only 70 pA. Under the bias of −15 V and the illumination of 254 nm, the maximum photo-to-dark current ratio reached 20, and the response time was less than 300 ms. Moreover, the detector exhibited a fast response time and remained very stable after numerous testing cycles. These results demonstrate the potential application of NaTaO3/TiO2 composites in UV detection.

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Journal articles on the topic 'UV photon detector'

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