scholarly journals Research and Selection of Prospective Materials for Activation Dosimetry of Intense Bremsstrahlung Radiation

2020 ◽  
Keyword(s):  
Gamma Radiation ◽  
Systematic Error ◽  
Gamma Ray ◽  
Gamma Spectrum ◽  
Equivalent Dose ◽  
Gamma Line ◽  
High Threshold ◽  
Bremsstrahlung Radiation ◽  
60Co Source ◽  
Wide Energy

Radiation technologies based on the use of powerful electron beams and gamma radiation are closely related to the need for dosimetry of these beams. Dosimetry based on the use of the inelastic gamma-ray scattering reaction on a number of nuclei with the formation of isomers with different half-lives and energies of radiation quanta is very successful for these purposes. An example of this application in dosimetry is the 115In (γ,γ')115mIn reaction, which results in the formation of the 115mIn isomer, having a gamma line with an energy of 336.24 keV and a half-life of 4.5 hours. There was a successful application of this technique in dosimetry in solving certain practical problems (irradiation complexes based on 60Co source- cobalt “guns”). In this work, it is shown that the use of In detectors for dosimetry of gamma-radiation with a wide energy spectrum (bremsstrahlung) is associated with significant uncertainty in measuring the equivalent dose of the gamma spectrum with an upper limit of 10 MeV. This uncertainty is due to the relatively high threshold of the aforementioned reaction of 1.08 MeV. The quantitative contribution to the total radiation flux of the region of the gamma spectrum below the threshold (γ,γ') of the reaction on the In nucleus was determined and it was shown that, depending on the direction of radiation, there is an systematic error in measuring the equivalent dose, reaching 20-60%. Investigated and proposed for use alternative materials detectors, allowing reducing the systematic error in measuring the equivalent dose to 2-3%, which is quite acceptable for practical use.

Effect of Gamma Radiation on Structural, Optical and Electrical Properties of nanostructured CdHgTe Thin Films

2018 ◽  
Vol 1 (1) ◽  
pp. 26-31 ◽  
Author(s):  
B Babu ◽  
K Mohanraj ◽  
S Chandrasekar ◽  
N Senthil Kumar ◽  
B Mohanbabu
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Gamma Radiation ◽  
Glass Substrate ◽  
Gamma Ray ◽  
Optical And Electrical Properties ◽  
Deposition Technique ◽  
Polycrystalline Structure ◽  
Dc Electrical Conductivity

CdHgTe thin films were grown onto glass substrate via the Chemical bath deposition technique. XRD results indicate that a CdHgTe formed with a cubic polycrystalline structure. The crystallinity of CdHgTe thin films is gradually deteriorate with increasing the gamma irradiation. EDS spectrums confirms the presence of Cd, Hg and Te elements. DC electrical conductivity results depicted the conductivity of CdHgTe increase with increasing a gamma ray dosage

sorbed dose must be measured by placing dose meters into the carriers, as described in Section V. If all of the gamma radiation coming from the 60Co source were absorbed by the irradiated goods, the radiation facility would have % irradiation efficiency. This is of course impossible because some of the radiation will be absorbed by the concrete shielding, by the carrier metal, and by the water below the source rack. Well-designed gamma facilities have an efficiency of about 30%. Designs differ­ ent from that shown in Figure 3 may use tote boxes on a conveyor belt instead of carriers hanging from a monorail, or the carriers may move around the source in a double loop instead of a single loop. Storage of the radioactive source in air in a concrete-shielded or lead-shielded cask instead of the water pool is also possible but is not often practiced. The outside appearance of a gamma irradiation facility is not much different from that of any other small or medium size industrial plant. A view of the first irradiation plant in the United States designed exclusively for the processing of foods (1) is shown in Figure 4. In principle, a 137Cs irradiator operates exactly like a 60Co irradiator. Some­ what less concrete shielding (1.2 m) is needed because the 0.66 MeV gamma rays of ,37Cs are less penetrating than the 1.33 MeV of Co. The longer half-life of

1995 ◽  
pp. 33-33
Keyword(s):  
United States ◽  
Gamma Radiation ◽  
Half Life ◽  
The United States ◽  
Conveyor Belt ◽  
Radioactive Source ◽  
Industrial Plant ◽  
Medium Size ◽  
Double Loop ◽  
60Co Source

scholarly journals Testing for presence of radioactivity in BC Pacific Ocean’s seafood supply

2014 ◽  
Author(s):  
Amy Luan ◽  
BCIT School of Health Sciences, Environmental Health ◽  
Bobby Sidhu ◽  
Abderrachid Zitouni
Keyword(s):  
Pacific Ocean ◽  
Gamma Radiation ◽  
Nuclear Power ◽  
Gamma Ray ◽  
Gamma Ray Spectrometer ◽  
The Pacific ◽  
Two Samples ◽  
Seafood Products ◽  
The Pacific Ocean ◽  
Fish And Shellfish

  Abstract: Due to the Fukushima Daiichi Nuclear power plant incident in March 2011, large quantities of contaminated water were released to the Pacific Ocean in Japan. The severity of contamination on the marine environment is unclear, therefore, the public is concerned with the possible internal radiation exposure from ingesting contaminated seafood products caught in the Pacific Ocean. This study was aimed to investigate the presence or absence of gamma radioactivity in commonly consumed seafood products from B.C. In total, ten different species of fish and three different species of shellfish were selected for analysis. For each species of fish, two samples were collected and each sample was from a different local seafood market. For each species of shellfish, ten samples were collected from three different sources. Using the portable GR-135 Plus gamma ray spectrometer, the samples were tested and analyzed for the presence of Fukushima radionuclides, particularly Cesium-137 (Cs-137) and Cesium- 134 (Cs-134).Based on the analyzed fish and shellfish, no gamma radiation was detected. The detector did not identify any gamma radiation over the normal background readings.  

THE TOTAL GAMMA RAY ACTIVITY OF SEDIMENTARY ROCKS AS INDICATED BY GEIGER COUNTER DETERMINATIONS

Geophysics ◽  
1944 ◽  
Vol 9 (2) ◽  
pp. 180-216 ◽  
Author(s):  
W. L. Russell
Keyword(s):  
Gamma Radiation ◽  
Frequency Distribution ◽  
Gamma Ray ◽  
Sedimentary Rocks ◽  
Geiger Counter ◽  
Rock Samples

Geiger counter determinations of the gamma ray intensity of 510 rock samples have been made to determine the average radioactivity and frequency distribution of radioactivities of the various types of sedimentary rocks. The results, expressed in units of gamma ray intensity, show that limestones, sandstones and dolomites are of relatively low radioactivity, shales much higher, and black bituminous shales highest of all. The new data on the gamma radiation of the sediments may be used to improve the interpretation of radioactivity logs and to determine the value of surface radioactivity surveys.

Leveling airborne gamma‐radiation data using between‐channel correlation information

Geophysics ◽  
1987 ◽  
Vol 52 (11) ◽  
pp. 1557-1562 ◽  
Author(s):  
A. A. Green
Keyword(s):  
Linear Regression ◽  
Gamma Radiation ◽  
Multiple Linear Regression ◽  
Linear Function ◽  
Gamma Ray ◽  
Background Correction ◽  
Channel Correlation ◽  
Radiation Data ◽  
Correlation Information ◽  
Correction Terms

A procedure for estimating background‐correction terms for the uranium channel of an airborne gamma‐ray survey has been developed. The residuals obtained from a multiple linear regression of flight‐line means for the uranium channel on the means for thorium and potassium are used to correct the uranium channel for each line. The procedure assumes that, were it not for these background errors, the uranium flight‐line means would be a linear function of the means for potassium and thorium. It also assumes that the background correction is the same for the whole of each line. In spite of these limitations, the method produces good background estimates consistent with those found by more sophisticated methods.

Detection of high-energy gamma radiation from quasar 3C 279 by the EGRET telescope on the Compton Gamma Ray Observatory

1992 ◽  
Vol 385 ◽  
pp. L1 ◽  
Author(s):  
R. C. Hartman ◽  
D. L. Bertsch ◽  
C. E. Fichtel ◽  
S. D. Hunter ◽  
G. Kanbach ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Gamma Ray ◽  
High Energy ◽  
High Energy Gamma ◽  
Energy Gamma

Detection of Prompt Gamma Radiation Near the LVR-15 Research Reactor

2019 ◽  
Vol 186 (2-3) ◽  
pp. 244-248
Author(s):  
Ladislav Viererbl ◽  
Vít Klupák ◽  
Antonín Kolros ◽  
Hana Assmann Vratislavská ◽  
Zdena Lahodová
Keyword(s):  
Gamma Radiation ◽  
Energy Range ◽  
Research Reactor ◽  
Reactor Core ◽  
Pulse Height ◽  
Wide Energy Range ◽  
Prompt Gamma ◽  
Reactor Building ◽  
Wide Energy ◽  
Prompt Gamma Radiation

Abstract The paper describes a method of pulse height spectrum measurement in a wide energy range. The LVR‑15 research reactor building was chosen to demonstrate this method. Pulse height spectra were measured on the third floor of the reactor building. Two types of scintillation detectors, NaI (Tl) and a plastic scintillator, were used. The detectors were placed for about 25 m from the reactor core, thus, separated from the primary circuit water in the reactor pool, biological shielding, building wall and other constructional materials. Spectra were measured in a wide energy range from 30 keV to 1000 MeV, in which signals were recorded from natural and man-made radionuclides, prompt gamma radiation and cosmic radiation. Experimental data were collected both while the reactor was in operation and while it was out of operation. This study confirms that differences in these spectra can be detected remotely over relatively large distances from the reactor core by adequately simple detection means.

scholarly journals Low Velocity Impact and Compression after Impact Properties on Gamma Irradiated Kevlar/Oil Palm Empty Fruit Bunch Hybrid Composites

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 646
Author(s):  
Siti Madiha Muhammad Amir ◽  
Mohamed Thariq Hameed Sultan ◽  
Ain Umaira Md Shah ◽  
Mohammad Jawaid ◽  
Syafiqah Nur Azrie Safri ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Oil Palm ◽  
Composite Structures ◽  
Gamma Ray ◽  
Hybrid Composites ◽  
Low Velocity Impact ◽  
Empty Fruit Bunch ◽  
Low Velocity ◽  
Velocity Impact ◽  
Compression After Impact

This work investigates the dynamic impact response of Kevlar/oil palm empty fruit bunch (EFB) hybrid composite structures with/without gamma radiation under low velocity impact (LVI) and compression after impact (CAI) test. The layering pattern Kevlar/oil palm EFB/Kevlar (K/OP/K) was applied in this work. Irradiation with gamma ray with various doses were applied from 25–150 kGy. LVI results shows that hybrid Kevlar/oil palm EFBs (Kevlar/OPEFB) that were not irradiated have greater impact resistance as compared to irradiated hybrid Kevlar/OPEFB. It was also observed that the hybridization of Kevlar/OPEFB with gamma irradiation helped to improve the compressive residual strength of the composites. It was found that Kevlar/OPEFB hybrid composites with the layering sequence K/OP/K can withstand up to 35 J of impact energy, with the optimum gamma radiation dose at 50 kGy.

Sign in / Sign up

Export Citation Format

Share Document