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Silicon detector

Daniela Poppinga, Jannik Halbur, Sarah Lemmer, Bjoern Delfs, Dietrich Harder, Hui Khee Looe, Bjoern Poppe
The aim of this test study is to check whether boron nitride (BN) might be applied as a detector material in high energy photon-beam dosimetry. Boron nitride is a compound of boron and nitrogen and exists in various crystalline forms. Hexagonal boron nitride (h-BN) possesses high mobility of the electrons and holes as well as a high volume resistivity, so that ionizing radiation in the clinical range of the dose rate can be expected to produce a measurable electrical current at low background current. Due to the low atomic numbers of its atomic constituents, its density (2...
July 25, 2017: Physics in Medicine and Biology
Jakub W Trzciński, Roberta Pinalli, Nicolò Riboni, Alessandro Pedrini, Federica Bianchi, Stefano Zampolli, Ivan Elmi, Chiara Massera, Franco Ugozzoli, Enrico Dalcanale
In this work we report a comprehensive study leading to the fabrication of a prototype sensor for environmental benzene monitoring. The required high selectivity and ppb-level sensitivity are obtained by coupling a silicon-integrated concentration unit containing the specifically designed EtQxBox cavitand to a miniaturized PID detector. In the resulting stand-alone sensor, the EtQxBox receptor acts at the same time as highly sensitive preconcentrator for BTEX and GC-like separation phase, allowing for the selective desorption of benzene over TEX...
April 28, 2017: ACS Sensors
Andrew J Wroe, Grant McAuley, Anthony V Teran, Jeannie Wong, Marco Petasecca, Michael Lerch, James M Slater, Anatoly B Rozenfeld
As technology continues to develop, external beam radiation therapy is being employed, with increased conformity, to treat smaller targets. As this occurs, the dosimetry methods and tools employed to quantify these fields for treatment also have to evolve to provide increased spatial resolution. The team at the University of Wollongong has developed a pixelated silicon detector prototype known as the dose magnifying glass (DMG) for real-time small-field metrology. This device has been tested in photon fields and IMRT...
July 18, 2017: Journal of Applied Clinical Medical Physics
Enrique Muñoz, John Barrio, Ane Etxebeste, Pablo Garcia Ortega, Carlos Lacasta, Josep Francisco Oliver, Carles Solaz, Gabriela Llosa
Compton imaging devices have been proposed and studied for a wide range of applications. We have developed a Compton camera prototype which can be operated with two or three detector layers based on monolithic lanthanum bromide (LaBr3) crystals coupled to silicon photomultipliers (SiPMs), to be used for proton range verification in hadron therapy. In this work, we present the results obtained with our prototype in laboratory tests with radioactive sources and in simulation studies...
July 18, 2017: Physics in Medicine and Biology
Jae Sung Lee, Gil Kovalski, Tali Sharir, Dong Soo Lee
Advances in imaging instrumentation and technology have greatly contributed to nuclear cardiology. Dedicated cardiac SPECT cameras incorporating novel, highly efficient detector, collimator, and system designs have emerged with the expansion of nuclear cardiology. Solid-state radiation detectors incorporating cadmium zinc telluride, which directly convert radiation to electrical signals and yield improved energy resolution and spatial resolution and enhanced count sensitivity geometries, are increasingly gaining favor as the detector of choice for application in dedicated cardiac SPECT systems...
July 17, 2017: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
Tobias Schmitz, Matthias Blaickner
A BNCT online neutron monitoring system was tested in a TRIGA reactor, using a silicon PIN-diode with a conversion foil. The setup was tested with different reactor powers at the hot and cold ends of the irradiation channel, using activation foils to compare with measured fluxes. The results demonstrate good reproducibility and show a linear correlation between signal of the PIN-diode and neutron flux at all positions, demonstrating this approach to be suitable for online monitoring of the neutron flux.
July 8, 2017: Applied Radiation and Isotopes
Jinglong Zhang, Michael E Moore, Zhonghai Wang, Zhou Rong, Chaowen Yang, Jason P Hayward
Choosing a digitizer with an appropriate sampling rate is often a trade-off between performance and economy. The influence of sampling rates on the neutron-gamma Pulse Shape Discrimination (PSD) with a solid stilbene scintillator coupled to a Silicon Photomultiplier was investigated in this work. Sampling rates from 125MSPS to 2GSPS from a 10-bit digitizer were used to collect detector pulses produced by the interactions of a Cf-252 source. Due to the decreased signal-to-noise ratio (SNR), the PSD performance degraded with reduced sampling rates...
June 23, 2017: Applied Radiation and Isotopes
Minyue Yang, Mingyu Li, Jian-Jun He
We proposed a large aperture push-broom static Fourier transform (FT) imaging spectrometer for hyper-spectral imaging. The spectroscopic system was based on the silicon-on-insulator (SOI) platform, consisting of spot size converters, a Mach-Zehnder interferometer (MZI) array, and a detector array. The arm length differences of the 201 MZI arrays are linearly varied. It is one on-chip FT spectrometer operating in a large spectral range from 1100 to 1700 nm with a resolution of 24  cm<sup>-1</sup> and small foot print (chip size: 11  mm×15  mm)...
July 15, 2017: Optics Letters
Minsong Wei, Kaiyuan Yao, Yumeng Liu, Chen Yang, Xining Zang, Liwei Lin
An ultraviolet detector is demonstrated through a whole-wafer, thin diamond film transfer process to realize the heterojunction between graphene and microcrystalline diamond (MCD). Conventional direct transfer processes fail to deposit graphene onto the top surface of the MCD film. However, it is found that the 2 µm thick MCD diamond film can be easily peeled off from the growth silicon substrate to expose its smooth backside for the graphene transfer process for high-quality graphene/MCD heterojunctions. A vertical graphene/MCD/metal structure is constructed as the photodiode device using graphene as the transparent top electrode for solar-blind ultraviolet sensing with high responsivity and gain factor...
July 11, 2017: Small
Nikolina Vicoroski, Anthony Espinoza, Mitchell Duncan, Bradley Michael Oborn, Martin Carolan, Peter Metcalfe, David Menichelli, Vladimir L Perevertaylo, Michael L F Lerch, Anatoly B Rosenfeld, Marco Petasecca
PURPOSE: The aim of in-vivo skin dosimetry is to measure the absorbed dose to the skin during radiotherapy, when treatment planning calculations cannot be relied on. It is of particularly importance in hypo-fractionated stereotactic modalities, where excessive dose can lead to severe skin toxicity. Currently commercial diodes for such applications are with water equivalent depths ranging from 0.5 to 0.8 mm. In this study, we investigate a new detector for skin dosimetry based on a silicon epitaxial diode, referred to as the skin diode...
July 11, 2017: Medical Physics
Michal Košťál, Jaroslav Šoltés, Ladislav Viererbl, Zdeněk Matěj, František Cvachovec, Vojtěch Rypar, Evžen Losa
A well-defined neutron spectrum is an essential tool for calibration and tests of spectrometry and dosimetry detectors, and evaluation methods for spectra processing. Many of the nowadays used neutron standards are calibrated against a fission spectrum which has a rather smooth energy dependence. In recent time, at the LVR-15 research reactor in Rez, an alternative approach was tested for the needs of fast neutron spectrometry detector calibration. This process comprises detector tests in a neutron beam, filtered by one meter of single-crystalline silicon, which contains several significant peaks in the fast neutron energy range...
June 27, 2017: Applied Radiation and Isotopes
Linda Ahnen, Helene Stachel, Stefan Kleiser, Cornelia Hagmann, Jingjing Jiang, Alexander Kalyanov, Scott Lindner, Martin Wolf, Salvador Sanchez
Imaging brain oxygenation is crucial for preventing brain lesions in preterm infants. Our aim is to build and validate a near-infrared optical tomography (NIROT) sensor for the head of neonates. This sensor, combined with an optoacoustic device, will enable quantitative monitoring of the structural and functional information of the brain. Since the head of preterm infants is small and fragile great care must be taken to produce a comfortable and compact device in which a sufficient number of light sources and detectors can be implemented...
2017: Advances in Experimental Medicine and Biology
Aleksander Sesek, Andrej Zemva, Janez Trontelj
BACKGROUND: The THz sensors using microbolometers as a sensing element are reported as one of the most sensitive room-temperature THz detectors suitable for THz imaging and spectroscopic applications. Microbolometer detectors are usually fabricated using different types of the MEMS technology. The patent for the detection system presented in this paper describes a method for microbolometer fabrication using a standard CMOS technology with advanced micromachining techniques. The measured sensitivity of the sensors fabricated by the patented method is 1000 V/W at an optimal frequency and is determined by the performance of a double-dipole antenna and quarter-wavelength resonant cavity...
July 4, 2017: Recent Patents on Nanotechnology
T Masuda, S Okubo, H Hara, T Hiraki, S Kitao, Y Miyamoto, K Okai, R Ozaki, N Sasao, M Seto, S Uetake, A Yamaguchi, Y Yoda, A Yoshimi, K Yoshimura
We developed a fast X-ray detector system for nuclear resonant scattering (NRS) experiments. Our system employs silicon avalanche photo-diode (Si-APD) as a fast X-ray sensor. The system is able to acquire both timing and energy of a single X-ray photon simultaneously in a high rate condition, 10(6) counts per second for one Si-APD. The performance of the system was investigated in SPring-8, a synchrotron radiation facility in Japan. Good time resolution of 120 ps (FWHM) was achieved with a slight tail distribution in the time spectrum by a level of 10(-9) at 1 ns apart from the peak...
June 2017: Review of Scientific Instruments
E Sahin, F L Bello Garrote, Y Tsunoda, T Otsuka, G de Angelis, A Görgen, M Niikura, S Nishimura, Z Y Xu, H Baba, F Browne, M-C Delattre, P Doornenbal, S Franchoo, G Gey, K Hadyńska-Klȩk, T Isobe, P R John, H S Jung, I Kojouharov, T Kubo, N Kurz, Z Li, G Lorusso, I Matea, K Matsui, D Mengoni, P Morfouace, D R Napoli, F Naqvi, H Nishibata, A Odahara, H Sakurai, H Schaffner, P-A Söderström, D Sohler, I G Stefan, T Sumikama, D Suzuki, R Taniuchi, J Taprogge, Z Vajta, H Watanabe, V Werner, J Wu, A Yagi, M Yalcinkaya, K Yoshinaga
The level structure of the neutron-rich ^{77}Cu nucleus is investigated through β-delayed γ-ray spectroscopy at the Radioactive Isotope Beam Factory of the RIKEN Nishina Center. Ions of ^{77}Ni are produced by in-flight fission, separated and identified in the BigRIPS fragment separator, and implanted in the WAS3ABi silicon detector array, surrounded by Ge cluster detectors of the EURICA array. A large number of excited states in ^{77}Cu are identified for the first time by correlating γ rays with the β decay of ^{77}Ni, and a level scheme is constructed by utilizing their coincidence relationships...
June 16, 2017: Physical Review Letters
J P Liu, J Kirchhoff, L Zhou, M Zhao, M D Grapes, D S Dale, M D Tate, H T Philipp, S M Gruner, T P Weihs, T C Hufnagel
A technique for measuring interdiffusion in multilayer materials during rapid heating using X-ray reflectivity is described. In this technique the sample is bent to achieve a range of incident angles simultaneously, and the scattered intensity is recorded on a fast high-dynamic-range mixed-mode pixel array detector. Heating of the multilayer is achieved by electrical resistive heating of the silicon substrate, monitored by an infrared pyrometer. As an example, reflectivity data from Al/Ni heated at rates up to 200 K s(-1) are presented...
July 1, 2017: Journal of Synchrotron Radiation
D S Schneider, A Bablich, M C Lemme
We report on the integration of large area CVD grown single- and bilayer graphene transparent conductive electrodes (TCEs) on amorphous silicon multispectral photodetectors. The broadband transmission of graphene results in 440% enhancement of the detectors' spectral response in the ultraviolet (UV) region at λ = 320 nm compared to reference devices with conventional aluminum doped zinc oxide (ZnO:Al) electrodes. The maximum responsivity of the multispectral photodetectors can be tuned in their wavelength from 320 nm to 510 nm by an external bias voltage, allowing single pixel detection of UV to visible light...
June 29, 2017: Nanoscale
Giacomo Reggiori, Antonella Stravato, Maria Pimpinella, Francesca Lobefalo, Vanessa De Coste, Antonella Fogliata, Pietro Mancosu, Fiorenza De Rose, Valentina Palumbo, Marta Scorsetti, Stefano Tomatis
PURPOSE: The increasing interest in SBRT treatments encourages the use of flattening filter free (FFF) beams. Aim of this work was to evaluate the performance of the PTW60019 microDiamond detector under 6MV and 10MVFFF beams delivered with the EDGE accelerator (Varian Medical System, Palo Alto, USA). A flattened 6MV beam was also considered for comparison. METHODS: Short term stability, dose linearity and dose rate dependence were evaluated. Dose per pulse dependence was investigated in the range 0...
June 2017: Physica Medica: PM
Q Ji, C-J Lin, C Tindall, M Garcia-Sciveres, T Schenkel, B A Ludewigt
Tagging of neutrons (2.45 MeV) with their associated (3)He particles from deuterium-deuterium (D-D) fusion reactions has been demonstrated in a compact neutron generator setup enabled by a high brightness, microwave-driven ion source with a high fraction of deuterons. Energy spectra with well separated peaks of the D-D fusion reaction products, (3)He, tritons, and protons, were measured with a silicon PIN diode. The neutrons were detected using a liquid scintillator detector with pulse shape discrimination...
May 2017: Review of Scientific Instruments
V Augustyns, M Trekels, H P Gunnlaugsson, H Masenda, K Temst, A Vantomme, L M C Pereira
We describe an experimental setup for conversion electron Mössbauer spectroscopy (CEMS) at low temperature. The setup is composed of a continuous flow cryostat (temperature range of 4.2-500 K), detector housing, three channel electron multipliers, and corresponding electronics. We demonstrate the capabilities of the setup with CEMS measurements performed on a sample consisting of a thin enriched (57)Fe film, with a thickness of 20 nm, deposited on a silicon substrate. We also describe exchangeable adaptations (lid and sample holder) which extend the applicability of the setup to emission Mössbauer spectroscopy as well as measurements under an applied magnetic field...
May 2017: Review of Scientific Instruments
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