Integration of the differential evolution algorithm and the Monte Carlo code to create a spectrometric detector model

A standard procedure for characterizing the high-purity germanium detector (HPGe), manufactured by Canberra Industries Inc [1], is performed directly by the company using patented methods. However, the procedure is usually expensive and must be repeated because the characteristics of the HPGe crystal change over time. In this work, the principles of a technique are developed for use in obtaining and optimizing the detector characteristics based on a cost-effective procedure in a standard research laboratory. The technique requires that the detector geometric parameters are determined with maximum accuracy by the Monte Carlo method [2] in parallel with the optimization based on evolutionary algorithms. The development of this approach facilitates modeling of the HPGe detector as a standardized procedure. The results will be also beneficial in the development of gamma spectrometers and/or their calibrations before routine measurements.

Radioactivity of long-lived gamma emitters in egg

Radioactivity in egg was investigated. The targeted radionuclides were the long-lived gamma emitters 228Ra, 226Ra, and 40K. Measurements were carried out using a high purity germanium detector. The calculated annual effective dose due to egg consumption was 79 μSv yr-1, which forms 1/4 of the 290 μSv yr-1 world average ingestion exposure from natural sources. Hence, no radiological hazards exist from egg consumption due to the presence of the investigated radionuclides.

Study the radioactive concentration for soil samples contaminated with depleted uranium in Al-Nahrawan site at Baghdad governorate using high purity germanium detector

This study is investigating the radioactivity in soil samples at the Al-Nahrawan site. The radiation survey appears there are 3000 square meters area are contaminated with DU in AL-Nahrawan site identified using Geiger–Müller (GM) for radiation survey and gamma spectrometry for 52 soil samples analysis taken from AL-Nahrawan site at different depths (0-70) cm and different locations. The results of gamma analysis using high-purity germanium show that the ratio between 235U/238U is less than 0.00720 (neutral ratio), and it has different values from 0.002-0.00588, and the average value of radioactive nuclides concentration for (238U, 235U and 40K) are (76019.61, 259.55 and 147.5) Bq/kg respectively, these values are higher than the (BG) radioactive concentration levels in Iraq for (238U and 235U) isotopes, and the analysis of 40K concentration appeared in the acceptable limits. The health effects of depleted uranium in the human body it is exposed to many health troubles through the entry of uranium oxide particles.

Natural Radioactivity in Soil and Bitumen in Al-Marj Spring and Abu-Jir Village, Anbar, Western Iraq

The aim of the present research is to illustrate γ-ray levels emitting from soil and bitumen producing from 238U, 232Th, and 40K along Abu-Jir Fault Zone. in the area extended from Al-Marj valley to Abu-Jir village using scintillometer device. Such study is important in environmental assessment to buildup data base about radioactivity. The concentration of natural radionuclides in the study area was determined to be occurring mostly in the clay minerals and organic matter. A high purity germanium spectrometer was used to detect the activity of these elements which ranged between 00.6±18.1- 1526±102, 0- 8.4±1.4, and 70.1±10.9- 328.2±73 in soil, and 28.2±5.6- 94±22.1, 0- 2.2±0.5, and 38.4±7.9- 70.1±10.9 in bitumen for 226Ra, 232Th, and 40K respectively. The anomaly of the Naturally occurring radioactive material was associated with hydrocarbon accumulation and springs. The source of 232Th and 40K came from the same source rock (illite), while 226Ra was associated with ascending fluids. The obtained results showed that the activity of 226Ra in soil has value above the world averages and other countries.

β-Delayed γ Emissions of 26P and Its Mirror Asymmetry

The study of the origin of asymmetries in mirror β decay is extremely important to understand the fundamental nuclear force and the nuclear structure. The experiment was performed at the National Laboratory of Heavy Ion Research Facility in Lanzhou (HIRFL) to measure the β-delayed γ rays of 26P by silicon array and Clover-type high-purity Germanium (HPGe) detectors. Combining with results from the β decay of 26P and its mirror nucleus 26Na, the mirror asymmetry parameter δ ( ≡ft+/ft−− 1) was determined to be 46(13)% for the transition feeding the first excited state in the daughter nucleus. Our independent results support the conclusion that the large mirror asymmetry is close to the proton halo structure in 26P.

Technology computer aided design based deep level transient spectra: Simulation of high-purity germanium crystals

Very often Deep Level Transient Spectroscopy (DLTS) specimens deviate from ideal textbook examples making the interpretation of spectra a huge challenge. This challenge introduces inaccurate estimates of the emission signatures and the lack of appropriate estimates for the concentrations of the observed trap levels. In this work it is shown with the example of high-purity germanium that Technology computer aided design including symbolic differentiation provides the necessary numerical stability over a wide temperature range to model DLTS spectra. Moreover this high-purity germanium is a quasi intrinsic semiconductor for which it is well-known that the original small signal theory can introduce strong errors. It is furthermore shown that the parasitic impact of fractional filling and high resistivity material can be modelled and that these modelled spectra can in the future assist the interpretation of experimental results.

Activity concentrations of 226^Ra, 232^Th, and 40^K in common maize meal consumed in Namibia and their potential radiation hazards

Gamma spectroscopy was performed to determine the concentrations of 40K, 226Ra and 232Th in maize meal samples collected from shop outlets and open markets in Namibia. The activity concentrations and Excess Lifetime Cancer Risk were determined using a high purity germanium (HPGe) detector. The average activity concentrations of 40K, 226Ra and 232Th were found to be 29.98 ± 4.05, 0.99 ± 0.40 and 0.35 ± 0.08 Bq.kg – 1 in the maize meal samples. The result showed the activity concentrations of 40K significantly higher than the other radionuclides in all the maize meal samples. The average excess life cancer risk varies from 1.33 x 10 – 13 to 6.05 x 10 – 13 for 40K, 8.76 x 10 -13 to 1.19 x 10 – 12 for 232Th and 2.43 x 10 -11 to 2.83 x 10 – 11 for 226Ra. Hence, when compared with internationally acceptable limits, all values fall within the safety limits. Thus, the study concludes that the maize meals consumed in Namibia are radiologically safe for consumption.

Support activities in Namie Town, Fukushima undertaken by Hirosaki University

This paper does not necessarily reflect the views of the International Commission on Radiological Protection. Several radiation monitoring research projects are underway on dose assessment, biological analysis, and risk communication under an agreement with Namie Town. Indoor radon and thoron progeny concentrations have been measured using passive-type monitors to estimate internal doses due to inhalation. In addition, airborne radiocaesium concentrations at five points in Namie Town have been analysed using a high-purity germanium detector to estimate internal doses for comparison with radon. External radiation doses from natural and artificial radionuclides have also been estimated using an in-situ gamma-ray spectrometer. Other support activities are mentioned briefly in this article,