scholarly journals Mixed ZnSxSe1–x Crystals as a Possible Material for Alpha-Particle and X-ray Detectors

2018 ◽  
Vol 63 (6) ◽  
pp. 546 ◽  
Author(s):  
O. G. Trubaieva ◽  
M. A. Chaika ◽  
O. V. Zelenskaya
Keyword(s):  
Sulfur Content ◽  
Alpha Particle ◽  
Light Yield ◽  
Alpha Particles ◽  
Mixed Crystals ◽  
Luminescence Spectra ◽  
X Rays ◽  
X Ray ◽  
Stockbarger Method ◽  
Luminescence Light

A possibility to use ZnSxSe1−x as a material for the detection of X-rays and alpha particles has been studied. The influence of the sulfur content on the properties of bulk ZnSxSe1−x crystals is analyzed. Six specimens with different component contents were grown, by using the Bridgman–Stockbarger method: ZnS0.07Se0.93, ZnS0.15Se0.85, ZnS0.22Se0.78, ZnS0.28Se0.72, ZnS0.32Se0.68, and ZnS0.39Se0.61. The intensity of X-ray luminescence spectra of ZnSxSe1−x crystals is found to increase with the sulfur content and reaches a maximum for the composition ZnS0.22Se0.78. The luminescence light yield of mixed ZnSxSe1−x crystals is higher than that of commercial ZnSe(Te) and ZnSe(Al) crystals. The advantages of mixed crystals based onZnSxSe1−x over the ZnS(Te) and ZnSe(Al) crystals have been discussed.

Use Of A Solid-State Detector for the Analysis of X-Rays Excited in Silicate Rocks by Alpha-Particle Bombardment

1971 ◽  
Vol 15 ◽  
pp. 388-406 ◽  
Author(s):  
Ernest J. Franzgrote
Keyword(s):  
Alpha Particle ◽  
Particle Bombardment ◽  
Pulse Height ◽  
Silicon Detector ◽  
Alpha Particles ◽  
X Rays ◽  
Solid State Detector ◽  
X Ray ◽  
Alpha Scattering ◽  
Silicate Rocks

The analysis of alpha-excited X-rays has been studied as a possible addition to the alpha-scattering technique used on the Surveyor spacecraft for the first in situ chemical analyses of the lunar surface.Targets of pure elements, simple compounds, and silicate rocks have been exposed to alpha particles and other radiation from a curium-214 source and the resulting X-ray spectra measured by means of a cooled lithium-drifted silicon detector and pulse-height analysis.Alpha-particle bombardment is a simple and efficient means of X-ray excitation for light elements. Useful spectra of silicate rocks may be obtained in a few minutes with a source activity of 50 millicuries, a detector area of 0.1 cm2 and a sample distance of 3 cm. An advantage over electron excitation is the higher characteristic response relative to the bremsstrahlung continuum. Peak-to- background ratios of greater than 100 to 1 have been obtained for elemental targets. Relative efficiencies of X-ray excitation by alpha particles and by X-rays from the curium source have been determined.Resolution of the detector system used is approximately 150 eV for the lighter elements. This is sufficient to resolve the Kα X-rays of the geochemically important elements, Na, Mg, Al, and Si in silicate rocks. Although these and lighter elements are analyzed as well or better by the alpha-scattering and alpha-proton technique, the X-ray mode enables results to be obtained more quickly.The study shows that the addition of an X-ray mode to the alpha-scattering analysis technique would result in a significant improvement in analytical capability for the heavier elements. In particular, important indicators of geochemical differentiation such as K and Ca (which are only marginally separated in an alpha-scattering and alpha-proton analysis) may be determined quantitatively by measuring the alpha-excited X-rays. An X-ray detector is under consideration as an addition to an alpha-scattering instrument now under development for possible use on a Mars-lander mission.

scholarly journals Non-induction of radioadaptive response in zebrafish embryos by neutrons

2016 ◽  
Vol 57 (3) ◽  
pp. 210-219 ◽  
Author(s):  
Candy Y.P. Ng ◽  
Eva Y. Kong ◽  
Alisa Kobayashi ◽  
Noriyoshi Suya ◽  
Yukio Uchihori ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Alpha Particles ◽  
Zebrafish Embryos ◽  
X Rays ◽  
X Ray ◽  
Challenging Dose ◽  
Neutron Exposure ◽  
Danio Rerio Embryos

Abstract In vivo neutron-induced radioadaptive response (RAR) was studied using zebrafish ( Danio rerio ) embryos. The Neutron exposure Accelerator System for Biological Effect Experiments (NASBEE) facility at the National Institute of Radiological Sciences (NIRS), Japan, was employed to provide 2-MeV neutrons. Neutron doses of 0.6, 1, 25, 50 and 100 mGy were chosen as priming doses. An X-ray dose of 2 Gy was chosen as the challenging dose. Zebrafish embryos were dechorionated at 4 h post fertilization (hpf), irradiated with a chosen neutron dose at 5 hpf and the X-ray dose at 10 hpf. The responses of embryos were assessed at 25 hpf through the number of apoptotic signals. None of the neutron doses studied could induce RAR. Non-induction of RAR in embryos having received 0.6- and 1-mGy neutron doses was attributed to neutron-induced hormesis, which maintained the number of damaged cells at below the threshold for RAR induction. On the other hand, non-induction of RAR in embryos having received 25-, 50- and 100-mGy neutron doses was explained by gamma-ray hormesis, which mitigated neutron-induced damages through triggering high-fidelity DNA repair and removal of aberrant cells through apoptosis. Separate experimental results were obtained to verify that high-energy photons could disable RAR. Specifically, 5- or 10-mGy X-rays disabled the RAR induced by a priming dose of 0.88 mGy of alpha particles delivered to 5-hpf zebrafish embryos against a challenging dose of 2 Gy of X-rays delivered to the embryos at 10 hpf.

scholarly journals Effect of sulfur on the scintillation properties of mixed ZnSxSe1–x crystals

2018 ◽  
pp. 36-42
Author(s):  
O. G. Trubaieva ◽  
M. A. Chaika ◽  
O. V. Zelenskaya ◽  
A. I. Lalayants ◽  
S. N. Galkin
Keyword(s):  
Directional Solidification ◽  
Sulfur Content ◽  
Light Output ◽  
Luminescent Properties ◽  
High Energy ◽  
Luminescence Spectra ◽  
Bulk Crystals ◽  
X Ray ◽  
Basic Properties ◽  
Better Than

ZnSxSe1–x based luminescent materials are promising for use as X-ray and g-ray detectors. The main advantage of ZnSxSe1–x crystals is the possibility of making of solid solutions over an entire X-range. It was found that varying the composition of ZnSxSe1–x crystals can change their luminescent properties. Many studies were focused on obtaining ZnSxSe1–x mixed crystals, most using a vapour phase growth methods, and only some of works used the directional solidification. The directional solidification techniques allow growing large ZnSxSe1–x crystals for high-energy particles detectors. Practical use, however, requires the knowledge about luminescent properties of ZnSxSe1–x bulk crystals. This study reports the effect of sulfur content on basic properties of ZnSxSe1–xx bulk crystals grown by Bridgman-Stockbarger method. Six different compounds were studied: ZnS0.07Se0.93, ZnS0.15Se0.85, ZnS0.22Se0.78, ZnS0.28Se0.72, ZnS0.32Se0.68, ZnS0.39Se0.61. The ZnSe(Al) and ZnSe(Te) crystals grown at the similar conditions were used as reference. X-ray luminescence was studied using РЕИС-И (REIS-I) X-ray source (Cu, U = 10—45 kV). КСВУ-23 (KSVU-23) spectrophotometer was used to analyse the emission spectra. The afterglow level h(%) was determined by Smiths Heimann AMS-1 spectrophotometer at excitation by such X-ray and g-ray sources as 123Cs and 241Am (59.5 keV). Light output is one of the main characteristics of the scintillator, which determines its quality as a detector. The ZnSxSe1-x crystals demonstrated increase in the intensity of X-ray induced luminescence spectra with increasing of sulfur content and reached maximum for ZnS0.22Se0.78 composition. Light output of ZnSxSe1–x bulk crystals are higher than those of ZnSe(Te) and ZnSe(Al) commercial crystals. Moreover, thermal stability of scintillation light output of ZnSxSe1–x bulk crystals are also better than those. This investigation has revealed that basic properties of ZnSxSe1–x based scintillation detectors are better than those of ZnSe(Te) and ZnSe(Al).

Investigation of Elemental Analysis of Water Samples by Radioalpha Induced X-Ray Emission Spectroscopy*

1974 ◽  
Vol 18 ◽  
pp. 333-342
Author(s):  
R. Hight ◽  
C. C. Foster
Keyword(s):  
Water Samples ◽  
Background Radiation ◽  
Trace Element Analysis ◽  
Alpha Particles ◽  
Particle Accelerators ◽  
X Rays ◽  
Element Analysis ◽  
Worst Case ◽  
Helium Atmosphere ◽  
X Ray

AbstractAlpha particles and protons from charged particle accelerators and photons from both x-ray tubes and radioactive sources have been shown to be useful for the excitation of characteristic x-rays for multi-element energy dispersive trace analysis of environmental samples to the few ppm range. We have investigated the use of 4.5 MeV alpha particles from a thin window Po-210 source of 5 mCi effective strength to directly excite x-rays from trace elements in 1 cc water samples evaporated on 1.75 mg/cm2 thick mylar backings in a helium atmosphere in a lucite enclosure. Minimum detectable amounts (MDA's) were established for 19 elements (22 ≤ Z ≤ 82) using K-, L- and M- radiation and 50 minute counting times. The smallest MDA determined was 0.11 μg for vanadium. Other representative MDA's, in μg, are Fe-0.54, Mo-0.31 and Pb-0.43. MDA's lower by an average factor of about 10 over an eight month source life would result from the use of 1 Ci of Po-210 for 50 minutes per sample. Thinner sample backings and improved source encapsulation will reduce background radiation and further improve sensitivity. Comparison of our MDA's (5 mCi-Po-210) with those of Blasius et al., who used radiophoton sources and 40,000 sec. counting times to determine trace metal pollutants in water samples, shows radioalpha excitation to have comparable sensitivity in the worst case, arsenic and better, by more than two orders of magnitude, sensitivity in the best case, vanadium.Radioalpha induced x-ray trace element analysis offers the same advantages of portability, ease of operation, low maintenance and cost, and "in house" availability as radiophoton induced analysis. Because of the availability of more intense sources (up to 10 Ci), the fact that the detected radiation (x-rays) differs from the excitation radiation (a-particles) and that K, L, and M x-ray emission cross-sections depend essentially only on the emitted x-ray energy, lower MDA's are obtainable for many elements in thin samples for comparable counting times, as well.

scholarly journals Photoluminescence and scintillation characteristics of Bi-loaded PVK-based plastic scintillators for the high counting-rate measurement of high-energy X-rays

RSC Advances ◽  
2021 ◽  
Vol 11 (26) ◽  
pp. 15581-15589
Author(s):  
Atsushi Sato ◽  
Arisa Magi ◽  
Masanori Koshimizu ◽  
Yutaka Fujimoto ◽  
Shunji Kishimoto ◽  
...  
Keyword(s):  
Counting Rate ◽  
Detection Efficiency ◽  
Light Yield ◽  
High Energy ◽  
X Rays ◽  
Rate Measurement ◽  
High Counting Rate ◽  
X Ray ◽  
Plastic Scintillators

Bi-loaded PVK-based plastic scintillators doped with bis-MSB are applicable for high counting-rate measurement of high-energy X-rays. They showed a higher detection efficiency and light yield than EJ-256 under 67.41 keV X-ray irradiation.

Hindsight 2020: X-ray Spectroscopy on Mars, Challenges, Results and Future.

2020 ◽  
Author(s):  
Ralf Gellert
Keyword(s):  
Large Scale ◽  
Landing Site ◽  
Ground Truth ◽  
Lessons Learned ◽  
Alpha Particles ◽  
Geochemical Data ◽  
X Rays ◽  
X Ray ◽  
The Past ◽  
Trade Offs

<p>Three generations of the Alpha-Particle-X-ray-Spectrometer (APXS) have been part of the science suite on all four landed NASA Mars rovers so far. Using x-ray spectroscopy following excitation with alpha particles and x-rays from <sup>244</sup>Cm radioactive sources, so far about 2000 samples have been investigated along the combined traverse of ~85km on the surface of Mars.</p><p>The APXS reports 16 standard elements in all samples and additional trace elements like Ge, Cu, Ga, Rb, Sr, As, Se, Y and Pb if at elevated levels. The sample spot of ~ 20 mm diameter is often large enough to represent bulk content, though small enough to reveal evidence for certain minerals through element correlations when oversampled in rasters. The results from all missions revealed large scale sedimentary formations, like Murray and Burns indicating specific environmental conditions in the past. The soil was found similar at all sites, representing a well mixed global crust component. APXS geochemical data were used for important constraints of complimentary mineralogy results, ground truth for orbiters and comparison to Martian meteorites.</p><p>Results from the ongoing Curiosity mission and the long living MER rovers will be discussed. Additionally, some very successful applications and investigations that were serendipitously developed after launch will be reviewed. Part of the presentation will be devoted to the unique challenges, trade-offs during design and lessons learned from the long operation of the instrument. The combination of APXS, XRD and Moesbauer results from MER and MSL with future fine scale XRF results of the soil at the Mars 2020 landing site might shed a light into the enigmatic amorphous phase, which could represent a record of the past alteration processes on Mars.</p>

Light yield sensitization by X-ray irradiation of the BaAl4O7:Eu2+ceramic scintillator obtained by full crystallization of glass

2014 ◽  
Vol 16 (45) ◽  
pp. 24824-24829 ◽  
Author(s):  
Gaël Patton ◽  
Federico Moretti ◽  
Andrei Belsky ◽  
Kholoud Al Saghir ◽  
Sébastien Chenu ◽  
...  
Keyword(s):  
Light Yield ◽  
X Rays ◽  
X Ray ◽  
Polycrystalline Ceramic ◽  
Crystallization Of Glass

We report the scintillation properties and light yield sensitization by X-rays of BaAl4O7:Eu2+, a transparent polycrystalline ceramic prepared by full and congruent crystallization of glass.

Monte Carlo simulations for the evaluation of various influence factors on projections in computed tomography

2010 ◽  
Vol 25 (2) ◽  
pp. 165-168
Author(s):  
B. Chyba ◽  
M. Mantler ◽  
M. Reiter
Keyword(s):  
Computed Tomography ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
National Laboratory ◽  
Light Yield ◽  
Thin Layers ◽  
Detector Response ◽  
X Rays ◽  
Los Alamos ◽  
X Ray

This paper presents Monte Carlo simulations considering all stages of the creation process of two-dimensional projections in a computed tomography (CT) device: excitation of angle dependent X-ray spectra within the X-ray tube using results from a previous study [Chyba et al. (2008). Powder Diffr. 23, 150–153]; interaction of these X-rays and secondary photoelectrons with a simple inhomogeneous sample; and interaction of X-rays and photoelectrons with the components (thin layers) of a matrix scintillation detector. The simulations were carried out by using custom software running on up to 50 nodes of a computer cluster. Comparative calculations were also made by using the software package MCNP [Booth et al. (2003). MCNP—A general Monte Carlo N-particle transport code, Report LAUR 03-1987, Los Alamos National Laboratory, Los Alamos, NM]. Tube spectra were calculated with algorithms proposed by Ebel [(2006). Adv. X-Ray Anal. 49, 267–273]. Measurements for the chosen setup made with an available CT device were in relatively good agreement with calculated results. It was shown that good knowledge of the tube spectra is of importance, but most differences between resulting projections and measurements are caused by uncertainties concerning detector response due to light yield of the scintillator and to internal scattering effects within the thin detector layers which lead to spreading of a detected point signal within the detector matrix into neighboring matrix elements.

Sign in / Sign up

Export Citation Format

Share Document