Search

We report on the quantitative nondestructive analysis of the natural isotopic abundances of hafnium and tungsten elements using nuclear resonance fluorescence. Metallic samples of hafnium and tungsten were irradiated to six quasi-monochromatic γ -ray beams generated by laser Compton scattering in the energy range of 2.4–3.2 MeV. Multiple nuclei were simultaneously excited at each of the six γ -ray beam energies. A high-purity germanium detector array detected deexcitations of the nuclei. In total, 51 transitions were unprecedentedly employed to estimate the isotopic abundances of heavy elements nondestructively. The estimated abundances of three hafnium isotopes and three tungsten isotopes are consistent with standard known natural abundances within the experimental uncertainties. The deviation from the standard values ranges from 0.18 % to 1.36 %. [ABSTRACT FROM AUTHOR]

Numerical calculations and experimental approaches are used to examine the slip characteristics of 1064 nm laser ablated single crystal germanium. The ablation and cooling processes are used to investigate the influence of laser power density on the creation of the slip process. A 1064 nm continuous laser and a nanosecond laser were used to ablate single-crystal germanium samples, and the damage to the surface was seen using an optical microscope. The results demonstrate that raising the laser power density to 107 W/cm2 efficiently suppresses slip production during laser processing. [ABSTRACT FROM AUTHOR]

Accurate quantum efficiency measurement not only provides crucial information for the photovoltaic cell industry but also supports experiments aimed at directly detecting dark matter and elastic neutrino interactions. The dark matter direct searches paradigm has recently expanded to include particles with masses below 1 , MeV / c 2 , where the expected signal in an electron–recoil interaction is approximately in the eV range, just above the energy gap for silicon and germanium. A robust calibration method for ionization signals in this lower energy region is essential. This paper presents a method for measuring quantum efficiency and yield (q/E) in semiconductors using phonon-mediated calorimetry. The Neganov–Trofimov–Luke phonon amplification method in low-temperature semiconductor crystals has been employed to indirectly measure ionization down to single-electron accuracy. Specifically, at zero bias, the phonon readout directly quantifies the total energy deposited within the detector, independent of the ionization yield. This eliminates a significant source of systematic uncertainty in quantum efficiency estimates associated with total energy uncertainty. The paper includes results from an updated ionization efficiency measurement in a germanium detector. [ABSTRACT FROM AUTHOR]

This work reports the first rotational bands observed in the neutron-deficient nucleus 231 U. Excited states were populated in the 232 Th(α ,5n) reaction at a beam energy of 52 MeV. Coincident decay γ -rays were measured with the high-purity germanium detectors of the afrodite spectrometer array, in conjunction with a recoil detector to discriminate against the fission background. The bands are interpreted as the ground-state band ν [ 633 ] 5 / 2 + , yrast band ν [ 752 ] 5 / 2 - , and an excited band ν [ 631 ] 3 / 2 + . Configuration assignments are supported by Cranked Shell Model and B(M1)/B(E2) calculations. The excitation energy of the ν [ 752 ] 5 / 2 - bandhead is suggested to be 113.0 keV. [ABSTRACT FROM AUTHOR]

The compound nucleus model is employed to calculate neutron capture on 76 Ge and the consecutive γ decay. Total, inelastic and capture cross sections are compared to experiments in order to restrict model parameters. The respective γ cascades are analyzed for possible background suppression schemes in future 0 ν β β decay searches with germanium detectors. Neutron energies in the range from 0.2 keV to 5 MeV are investigated. The spin dependence of the γ cascades is proposed to be employed for determining the spin of thermal resonances. [ABSTRACT FROM AUTHOR]

The sensitivities of light Dark matter particle searches with cryogenic detectors are mostly limited by large backgrounds of events that do not produce ionization signal. The CRYOSEL project develops a new technique, where this background in a germanium cryogenic detector is rejected by using the signals from a superconducting single electron device (SSED) sensor designed to detect the phonons emitted through the Neganov–Trofimov–Luke effect by the e - h + pairs as they drift in a nearby very high-field region. A tag on signals from this device should suppress the heat-only background. The measurement of the response to IR laser pulses of the first CRYOSEL prototype show the relevance of such sensor technology. [ABSTRACT FROM AUTHOR]

Here, we present a method for concentrating radiocesium in seawater using ammonium molybdophosphate-polyacrylonitrile (AMP-PAN) resin using custom-made sample-loading equipment. It was designed to reduce analytical time and labor with eight peristaltic pumps connected in parallel with eight columns, each packed with AMP-PAN. Eighty liters of seawater containing radiocesium were concentrated to 0.01 L in 6 h with the proposed method and Cs recovery was > 85%. The minimum detectable activity was 0.2 mBq L–1 at 160,000-s measurement with a high-purity germanium detector. [ABSTRACT FROM AUTHOR]

At the 3MV tandem accelerator of Sichuan University, monoenergetic neutrons were generated through the T(d,n)4He reaction by bombarding a Tritium–Titanium (T–Ti) target with a 2 MeV deuterium beam. The neutron activation method and offline gamma-ray spectroscopy were utilized to measure the cross sections of the 232Th(n,2n)231Th reaction at neutron energies of 12.49 ± 0.33 MeV, 16.38 ± 0.60 MeV, and 18.10 ± 0.23 MeV. Factors such as neutron scattering, neutron flux fluctuation, cascade coincidence effects in gamma-ray measurements, and gamma-ray self-absorption were analytically corrected. The TALYS-1.9 program was used to calculate the reaction cross sections of 232Th(n,2n)231Th within the 6–20 MeV neutron energy range. The experimental data were compared and analyzed against existing experimental data, evaluated data from CENDL-3.2, ENDF/B-VIII, JENDL-5, ROSFONDR-2010 and theoretical values computed by TALYS-1.9. [ABSTRACT FROM AUTHOR]

Radiological hazard assessment is an important task. The natural radionuclides in 88 surface soil samples in/surrounding high-level natural radiation areas were measured using a high-purity germanium gamma-ray detector. The 226Ra, 238U, 232Th, and 40K activities varied from 60.4 to 655, 59.3 to 643, 71.2 to 886, and 252 to 745 Bq/kg respectively. The highest radionuclides concentration was found in rare earth element mines, followed by uranium and metallic mines. There was an equilibrium between 238U and 226Ra with 238U/226Ra ratios equal to 1.01. The radiation hazard indices in the study soil samples were far higher than the world average values. [ABSTRACT FROM AUTHOR]

The mid‐infrared (mid‐IR) region is attractive for spectroscopy because this range has molecular fingerprint information. Existing FTIR‐based systems are limited by their complex optical systems, highlighting the ongoing necessity to advance miniaturization and simplify these systems. Here, a compact mid‐IR spectroscopy is introduced in the mid‐IR range, utilizing a continuously variable mid‐IR filter. This filter is made from Germanium (Ge) and BaF2 and is produced using physical vapor deposition. Continuously varying wavelengths of mid‐IR light are transmitted from different areas of the filter. These different wavelengths of light enter each pixel of the microbolometer array. Calibration is conducted using a sample material to match each pixel of the microbolometer array to its corresponding wavelength. Additionally, a deconvolution algorithm is applied to sharpen the acquired spectrum. This results in acquisition of high signal‐to‐noise ratio mid‐IR spectra in the LWIR region. Using this technology, mid‐IR spectroscopy for several types of samples like polymer film, and gas molecules is possible. In addition, by adopting total internal reflection, it is possible to measure non‐uniform thickness samples, such as liquid droplets. [ABSTRACT FROM AUTHOR]

Recently, phase change chalcogenides, such as monochalcogenides, are reported as switching materials for conduction‐bridge‐based memristors. However, the switching mechanism focused on the formation and rupture of an Ag filament during the SET and RESET, neglecting the contributions of the phase change phenomenon and the distribution and re‐distribution of germanium vacancies defects. The different thicknesses of germanium telluride (GeTe)‐based Ag/GeTe/Pt devices are investigated and the effectiveness of phase loops and defect loops future application in neuromorphic computing are explored. GeTe‐based devices with thicknesses of 70, 100, and 200 nm, are fabricated and their electrical characteristics are investigated. Highly reproducible phase change and defect‐based characteristics for a 100 nm‐thick GeTe device are obtained. However, 70 and 200 nm‐thick devices are unfavorable for the reliable memory characteristics. Upon further analysis of the Ag/GeTe/Pt device with 100 nm of GeTe, it is discovered that a state‐of‐the‐art dependency of phase loops and defect loops exists on the starting and stopping voltage sweeps applied on the top Ag electrode. These findings allow for a deeper understanding of the switching mechanism of monochalcogenide‐based conduction‐bridge memristors. [ABSTRACT FROM AUTHOR]

All living creatures in nature are constantly exposed to ionising radiation, which is emitted from natural and artificial radiation sources. For this reason, it is important to monitor the levels of radioactivity in living spaces and visited areas. In this study, natural (238U, 232Th, 40K) and artificial (137Cs) radioactivity concentrations in sediment samples taken from Borçka Black Lake located on the Nature Park in Artvin province were determined using a high purity germanium detector (HPGe). It was determined that 238U, 232Th, 40K and 137Cs radioisotope concentrations in the sediment samples varied between 8.73 and 26.45, 7.01 and 22.98, 289.92 and 578.98, and 6.26 and 70.96 Bq kg−1, respectively. Mean radioactivity concentrations were found to be 14.99 ± 0.89 Bq kg−1 for 238U, 13.85 ± 1.10 Bq kg−1 for 232Th, 473.67 ± 14.21 Bq kg−1 for 40K and 35.06 ± 0.96 Bq kg−1 for 137Cs. In order to evaluate the radiological hazards, radium equivalent activity, external hazard index, absorbed dose rate in the air, the annual effective dose rate and excess life time cancer risk were calculated and compared with the values recommended by international organisations. As a result, it has been shown with this study that the radioactivity caused by the examined radioisotopes will not pose any health risk for the visitors of Borçka Black Lake. [ABSTRACT FROM AUTHOR]

In this study, 16 sediment samples were collected from Bree, Klein-Brak, Bakens and uMngeni rivers of South Africa and were prepared, analysed and evaluated for the activity concentration of 238U, 232Th and 40K concerning its radiogenic heat production using a high-purity germanium detector. The results show that 238U is the prevalent radionuclide in radiogenic heat production, with 232Th and 40K emerging as trace elements. The mean activity concentrations are 28.97%, 63.69% and 7.34% for uranium, thorium and potassium, respectively, from all sampling locations. This shows that a high radioactive concentration of a specific radionuclide does not necessarily imply its increased contribution to radiogenic heat production. The radionuclide contributions to radiogenic heat production at all sampled locations are 59.39%, 35.11% and 5.50% for uranium, thorium and potassium, respectively. The mean radiogenic heat production rate in the study area ranged from 0.0180 $\mu Wm^{-3}$ μW m − 3 in sediment samples from the Bree River in Western Cape to 0.0072 $\mu Wm^{-3}$ μW m − 3 in sediment samples of uMgeni River in KwaZulu-Natal. All values obtained for this study are five times lower than the average continental radiogenic heat production of 1 $\mu Wm^{-3}$ μW m − 3 . This study provides insight into the radiogenic heat production rate due to the presence of radionuclides in all river samples. [ABSTRACT FROM AUTHOR]

Ultra-low-radioactivity titanium alloys are promising materials for the manufacture of low-background detectors which are being developed for experiments in astroparticle physics and neutrino astrophysics. Structural titanium is manufactured on an industrial scale from titanium sponge. The ultra-low-background titanium sponge can be produced on an industrial scale with a contamination level of less than 1 mBq/kg of uranium and thorium isotopes. The pathways of contaminants during the industrial production of structural titanium were analyzed. The measurements were carried out using two methods: inductively coupled plasma mass spectroscopy (ICP-MS) and gamma spectroscopy using high-purity germanium detectors (HPGes). It was shown that the level of contamination with radioactive impurities does not increase during the remelting of titanium sponge and mechanical processing. We examined titanium alloy samples obtained at different stages of titanium production, namely an electrode compaction, a vacuum arc remelting with a consumable electrode, and a cold rolling of titanium sheets. We found out that all doped samples that were studied would be a source of uranium and thorium contamination in the final titanium alloys. It has been established that the only product allowed obtaining ultra-low-background titanium was the commercial VT1-00 alloy, which is manufactured without master alloys addition. The master alloys in the titanium production process were found cause U/Th contamination. [ABSTRACT FROM AUTHOR]

Point-contact p-type high-purity germanium detectors (PPC HPGe) are particularly suited for detection of sub-keV nuclear recoils from coherent elastic scattering of neutrinos or light dark matter particles. While these particles are expected to interact homogeneously in the entire detector volume, specific classes of external background radiation preferably deposit their energy close to the semi-active detector surface, in which diffusion processes dominate that subsequently lead to slower rising pulses compared to the ones from the fully active bulk volume. Dedicated studies of their shape are therefore highly beneficial for the understanding and the rejection of these unwanted events. This article reports about the development of a data-driven pulse shape discrimination (PSD) method for the four 1 kg size PPC HPGe detectors of the Conus experiment in the keV and sub-keV regime down to 210 eV ee. The impact of the electronic noise at such low energies is carefully examined. It is shown that for an acceptance of 90% of the faster signal-like pulses from the bulk volume, approx. 50% of the surface events can be rejected at the energy threshold and that their contribution is fully suppressed above 800 eV ee. Applied to the Conus background data, such a PSD rejection cut allows to achieve an overall (15 - 25) % reduction of the total background budget. The new method allows to improve the sensitivity of future Conus analyses and to refine the corresponding background model in the sub-keV energy region. [ABSTRACT FROM AUTHOR]

The future Ricochet experiment aims to search for new physics in the electroweak sector by measuring the Coherent Elastic Neutrino-Nucleus Scattering process from reactor antineutrinos with high precision down to the sub-100 eV nuclear recoil energy range. While the Ricochet collaboration is currently building the experimental setup at the reactor site, it is also finalizing the cryogenic detector arrays that will be integrated into the cryostat at the Institut Laue Langevin in early 2024. In this paper, we report on recent progress from the Ge cryogenic detector technology, called the CryoCube. More specifically, we present the first demonstration of a 30 eVee (electron equivalent) baseline ionization resolution (RMS) achieved with an early design of the detector assembly and its dedicated High Electron Mobility Transistor (HEMT) based front-end electronics with a total input capacitance of about 40 pF. This represents an order of magnitude improvement over the best ionization resolutions obtained on similar phonon-and-ionization germanium cryogenic detectors from the EDELWEISS and SuperCDMS dark matter experiments, and a factor of three improvement compared to the first fully-cryogenic HEMT-based preamplifier coupled to a CDMS-II germanium detector with a total input capacitance of 250 pF. Additionally, we discuss the implications of these results in the context of the future Ricochet experiment and its expected background mitigation performance. [ABSTRACT FROM AUTHOR]

Background: The out‐of‐field radiation dose for boron neutron capture therapy (BNCT), which results from both neutrons and γ‐rays, has not been extensively evaluated. To safely perform BNCT, the neutron and γ‐ray distributions inside the treatment room and the whole‐body dose should be evaluated during commissioning. Although, certain previous studies have evaluated the whole‐body dose in the clinical research phase, no institution providing BNCT covered by health insurance has yet validated the neutron distribution inside the room and the whole‐body dose. Purpose: To validate the Monte Carlo model of the BNCT irradiation room extended for the whole‐body region and evaluate organ‐at‐risk (OAR) doses using the validated model with a human‐body phantom. Methods: First, thermal neutron distribution inside the entire treatment room was measured by placing Au samples on the walls of the treatment room. Second, neutron and gamma‐ray dose‐rate distributions inside a human‐body water phantom were measured. Both lying and sitting positions were considered. Bare Au, Au covered by Cd (Au+Cd), In, Al, and thermoluminescent dosimeters were arranged at 11 points corresponding to locations of the OARs inside the phantom. After the irradiation, γ‐ray peaks emitted from the samples were measured by a high‐purity germanium detector. The measured counts were converted to the reaction rate per unit charge of the sample. These measurements were compared with results of simulations performed with the Particle and Heavy Ion Transport code System (PHITS). A male adult mesh‐type reference computational phantom was used to evaluate OAR doses in the whole‐body region. The relative biological effectiveness (RBE)‐weighted doses and dose‐volume histograms (DVHs) for each OAR were evaluated. The median dose (D50%) and near‐maximum dose (D2%) were evaluated for 14 OARs in a 1‐h‐irradiation process. The evaluated RBE‐weighted doses were converted to equivalent doses in 2 Gy fractions. Results: Experimental results within 60 cm from the irradiation center agreed with simulation results within the error bars except at ±20, 30 cm, and those over 70 cm corresponded within one digit. The experimental results of reaction rates or γ‐ray dose rate for lying and sitting positions agreed well with the simulation results within the error bars at 8, 4, 11, 7 and 7, 4, 7, 6, 5, 6 out of 11 points, respectively, for Au, Au+Cd, In, Al, and TLD. Among the detectors, the discrepancies in reaction rates between experiment and simulation were most common for Au+Cd, but were observed randomly for measurement points (brain, lung, etc.). The experimental results of γ‐ray dose rates were systematically lower than simulation results at abdomen and waist regions for both positions. Extending the PHITS model to the whole‐body region resulted in higher doses for all OARs, especially 0.13 Gy‐eq increase for D50% of the left salivary gland. Conclusion: The PHITS model for clinical BNCT for the whole‐body region was validated, and the OAR doses were then evaluated. Clinicians and medical physicists should know that the out‐of‐field radiation increases the OAR dose in the whole‐body region. [ABSTRACT FROM AUTHOR]

The GERmanium Detector Array (Gerda) experiment operated enriched high-purity germanium detectors in a liquid argon cryostat, which contains 0.33% of 36 Ar, a candidate isotope for the two-neutrino double-electron capture (2 ν ECEC) and therefore for the neutrinoless double-electron capture (0 ν ECEC). If detected, this process would give evidence of lepton number violation and the Majorana nature of neutrinos. In the radiative 0 ν ECEC of 36 Ar, a monochromatic photon is emitted with an energy of 429.88 keV, which may be detected by the Gerda germanium detectors. We searched for the 36 Ar 0 ν ECEC with Gerda data, with a total live time of 4.34 year (3.08 year accumulated during Gerda Phase II and 1.26 year during Gerda Phase I). No signal was found and a 90% CL lower limit on the half-life of this process was established T 1 / 2 > 1.5 · 10 22 year. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine activity concentrations of Naturally Occuring Radioactive Materials (NORM) products and artificial radioisotopes in foods, and Brazil nut and Turkish hazelnut were selected from food products to be examined. The activity concentrations of 238U, 232Th, 40K, and 137Cs radioisotopes in Brazil nut and Turkish hazelnut products purchased from 4 different brands operating in the UK were determined by a high purity germanium detector (HPGe) that performs gamma-ray counting. Ethically; all brands were encoded as A, B, C, and D. Activity concentrations of 238U and 232Th in Brazil nut samples were found to lie in the range of 33.9 ± 0.4 ↔ 35.5 ± 0.4 Bq/kg and 19.0 ± 0.3 ↔ 31.3 ± 0.4 Bq/kg, respectively, whereas the activity concentrations of 238U and 232Th in Turkish hazelnut samples were below minimum detectable activity (MDA) values. In all samples, the most dominant sources of radioactivity were 40K in range of 220.0 ± 3.4 ↔ 242.0 ± 3.4 Bq/kg, and very low activity concentrations of 137Cs were detected only in Turkish hazelnut samples purchased from D and A brands as 1.1 ± 0.2 and 1.8 ± 0.1 Bq/kg, respectively. [ABSTRACT FROM AUTHOR]

The Laboratory of Analysis by Nuclear Reaction (LARN) at the University of Namur (Belgium) is equipped with a low background γ-ray detection system. This setup is made of one ton of lead as passive shielding and plastic scintillators as anti-cosmic active shielding that covers a large area around a 3.5 × 3.5 in.2 high purity germanium detector. This setup makes it possible to reduce the background level from two to three orders of magnitude, depending on the energy range of interest. In this work, this polyvalent detection system is described and used to refine the cross-section measurements of the 13C(p,γ)14N nuclear reaction at middle and low energies. The reaction 13C(p,γ)14N plays an important role in the carbon–nitrogen–oxygen cycle and s-process in stellar evolution. In this work, we studied more precisely the 13C(p,γ)14N ground transition (Eγ = 8.06 MeV) for incident energies ranging from 147 to 574.3 keV in the center-of-mass system generated by the 2 MV Tandetron accelerator ALTAÏS installed at the LARN. Our measurements performed both in reverse [i.e., 1H(13C,γ)14N] and direct kinematics are in good agreement with all the data available in the literature, validating our low background detection system. [ABSTRACT FROM AUTHOR]

A first search for rare decays of gadolinium isotopes was performed with an ultra-low background high-purity germanium detector at Gran Sasso Underground Laboratory (Italy). A 198 g Gd 2 O 3 powder sample was measured for 63.8 d with a total Gd exposure of 12.6 kg × d. 152 Gd is the most promising isotope for resonant enhanced neutrinoless double electron capture which could significantly increase the decay rate over other neutrinoless double beta decay processes. The half-life for this decay was constrained to > 4.2 × 10 12 year (90% credibility). This limit is still orders of magnitude away from theoretical predictions but it is the first established limit on the transition paving the way for future experiments. In addition, other rare alpha and double beta decay modes were investigated in 152 Gd, 154 Gd, and 160 Gd with half-life limits in the range of 10 17 - 20 year. [ABSTRACT FROM AUTHOR]

In an ideal germanium detector, fully-absorbed monoenergetic γ –rays will appear in the measured spectrum as a narrow peak, broadened into a Gaussian of width determined only by the statistical properties of charge cloud generation and the electronic noise of the readout electronics. Multielectrode detectors complicate this picture. Broadening of the charge clouds as they drift through the detector will lead to charge sharing between neighboring electrodes and, inevitably, low-energy tails on the photopeak spectra. We simulate charge sharing in our germanium cross strip detectors in order to reproduce the low-energy tails due to charge sharing. Our goal is to utilize these simulated spectra to develop an analytical fit (shape function) for the spectral lines that provides a robust and high-quality fit to the spectral profile, reliably reproduces the interaction energy, noise width, and the number of counts in both the true photopeak and the low-energy tail, and minimizes the number of additional parameters. Accurate modeling of the detailed line profiles is crucial for both calibration of the detectors as well as scientific interpretation of measured spectra. [ABSTRACT FROM AUTHOR]

The search for neutrinoless double-beta decay remains today one of the most important areas in particle and nuclear physics. Germanium detectors are an excellent technology for this search because of their state-of-the-art energy resolution, but a dead layer in a germanium crystal can reduce the active volume, which can affect both exposure and half-life sensitivity. In this work, we used machine learning methods to study the dead layer in enriched germanium crystals. 1000 sets of events were simulated with various combinations of dead layer parameters. A fully connected neural network was used to determine these parameters from the energy spectra of a germanium detector exposed to a gamma calibration source Barium-133. [ABSTRACT FROM AUTHOR]

Huge amount of coal combustion residue (CCR) is being generated in India every year. Since coal contains some natural radionuclides, the CCR may contribute to the enhanced natural radiation background. Hence, it is important to monitor the natural radioactivity levels in Indian CCR samples. The present study aims to estimate the natural radioactivity levels in CCRs produced in Indian thermal power plants. Accordingly, six CCR samples from different thermal power plants were collected and packed to achieve secular equilibrium among daughter products of 226Ra. The samples were counted for activity of gamma radionuclides using high purity germanium detector based high resolution gamma spectrometer. Results show that 40K is the most abundant among analyzed radionuclides, and the lowest was observed for 226Ra. Secular equilibrium was observed between 228Ra and 228Th, whereas no equilibrium was observed between 226Ra and 238U. The activity concentration for 226Ra and its daughter products (214Pb and 214Bi) was found to be similar in CCR sample before and after equilibrium, indicating that progenies are in secular equilibrium in CCR. The X ray diffraction analysis of CCR indicates the presence of aluminosilicate as major fraction, which has potential of trapping of 226Ra and daughter products. The values observed are very low and similar to those observed in naturally occurring radioactive materials such as coal, soil, and sediment, hence are not of radiological concern with respect to human/environment. [ABSTRACT FROM AUTHOR]

Oat is a nutritious healthy type of food that is widely consumed by various athletes and diet food in Iraq. This study aims to measure the natural radioactivity of potassium-40, Radium-226, and Radium-228 in rolled oat brands that are widely consumed in Iraq. Five types of oat brands retailed in Baghdad markets were collected and analyzed. A high-purity germanium detector was used for the gamma spectroscopy analysis. The mean activity concentration values of 226Ra, 228Ra, and 40K ranged from 6.9-10.6, 3.9-6.7, to 210-484 Bq/kg, respectively. The annual effective dose was the highest for a Ukrainian brand with 36.02 µSv/year, while the radium equivalent activity values range from 31.43 to 56.1 Bq/kg. The results of the study have been compared to a number of studies and showed good agreement. The findings of the paper show that regular consumption of these kinds of oats is radiologically safe for human health. [ABSTRACT FROM AUTHOR]

Objective. The results of a follow-up experiment investigating a novel method for sub-milimetre range verification (RV) in proton therapy (PT) are presented. Approach. The method consists of implanting a hadron tumour marker (HTM) near the planned treatment volume, and measuring the γ -ray signals emitted as a result of activation by the proton beam. These signals are highly correlated with the energy of the beam impinging on the HTM and can provide an absolute measurement of the range of the beam relative to the position of the HTM, which is independent of any uncertainties in beam delivery. Main results. Three candidate HTM materials were identified and combined into a single composite HTM, which makes use of the strongest reaction in each material. The setup of the previous experiment was improved on by using high-purity germanium detectors to measure the γ -ray signal with a higher resolution than was previously achieved. A PMMA phantom was also used to simulate the γ -ray background from tissue activation. HTM RV using the data collected in this study yielded range measurements whose average deviation from the expected value was 0.13(22)mm. Significance. Range uncertainty in PT limits the prescribed treatment plan for cancer patients with large safety margins and constrains the direction of the proton beam in relation to any organ at risk. The sub-milimetre range uncertainty achieved in this study using HTM RV, if implemented clinically, would allow for a reduction in the size of safety margins, increasing the therapeutic window for PT. [ABSTRACT FROM AUTHOR]

In Egyptian black sands, monazite is a precious mineral characterized by its composition, which includes crucial constituents such as thorium, trace amounts of uranium, and rare earth elements. It is essential to evaluate and quantify the extent of gamma-ray exposure resulting from the presence of primordial radionuclides. This necessity arises from human activities that extract and retrieve raw materials in uranium and thorium mining operations. The current study focuses on the radiological assessment of Monazite raw material in various grades and calculates the associated hazard indices. A hyper pure Germanium detector (HPGe) determined the particular activity. For grade, 90% Monazite samples, the average activities for 232Th, 238U, and 40K were 348,008 ± 1406, 69,299 ± 2086, and 27,510 ± 245 Bq/kg, respectively. For grade 75% Monazite samples, the average activities were 219,000 ± 901, 55,000 ± 500, and 18,300 ± 86 Bq/kg, while for grade 50% Monazite samples, it was 43,294 ± 1549, 9593 ± 629, and 4000 ± 211 Bq/kg for the same element, respectively. Also, 138La's inherent radioactivity was taken into account. The computed effective and absorbed dosages exceed the worker's exempt limit of 20 mSv/y. The calculated hazard parameters are higher than the maximum recommended limits. Therefore, it is imperative to employ radiation safety measures to mitigate the potential hazards of ionizing radiation. [ABSTRACT FROM AUTHOR]

We search for tri-nucleon decays of 76 Ge in the dataset from the GERmanium Detector Array (GERDA) experiment. Decays that populate excited levels of the daughter nucleus above the threshold for particle emission lead to disintegration and are not considered. The ppp-, ppn-, and pnn-decays lead to 73 Cu, 73 Zn, and 73 Ga nuclei, respectively. These nuclei are unstable and eventually proceed by the beta decay of 73 Ga to 73 Ge (stable). We search for the 73 Ga decay exploiting the fact that it dominantly populates the 66.7 keV 73 m Ga state with half-life of 0.5 s. The nnn-decays of 76 Ge that proceed via 73 m Ge are also included in our analysis. We find no signal candidate and place a limit on the sum of the decay widths of the inclusive tri-nucleon decays that corresponds to a lower lifetime limit of 1.2 × 10 26 yr (90% credible interval). This result improves previous limits for tri-nucleon decays by one to three orders of magnitude. [ABSTRACT FROM AUTHOR]

The materials characterization based on gamma measurements is one of the main features for verifying the radioactive materials for safeguards purposes. This work focuses on the optimization approach in order to find solutions that include some influence parameters, which should be taken into consideration during measurements. The considered samples in our work are certified reference nuclear materials of chemical composition (U3O8) with different enrichment ratios ranging from 0.31 wt.% to 4.46 wt.%. The gamma spectrometer based on a planar high-purity germanium detector of high-resolution was used in the current study. The study of various setups was experimentally carried out for different cans at different positions for different energy lines. The verified parameters influencing the characterization of the measured samples have been estimated. This approach for the measurement setup of the measured gamma spectra has been successfully explored to be very affected by different parameters such as the source to detector position and the various enrichment ratios. Consequently, the verified and characterized samples could be estimated based on this optimization approach. [ABSTRACT FROM AUTHOR]

The electric E1 and magnetic M1 dipole responses of the N = Z nucleus 24 Mg were investigated in an inelastic photon scattering experiment. The 13.0 MeV electrons, which were used to produce the unpolarised bremsstrahlung in the entrance channel of the 24 Mg( γ , γ ′ ) reaction, were delivered by the ELBE accelerator of the Helmholtz-Zentrum Dresden-Rossendorf. The collimated bremsstrahlung photons excited one J π = 1 - , four J π = 1 + , and six J π = 2 + states in 24 Mg. De-excitation γ rays were detected using the four high-purity germanium detectors of the γ ELBE setup, which is dedicated to nuclear resonance fluorescence experiments. In the energy region up to 13.0 MeV a total B (M 1) ↑ = 2.7 (3) μ N 2 is observed, but this N = Z nucleus exhibits only marginal E1 strength of less than ∑ B (E 1) ↑ ≤ 0.61 × 10 - 3 e 2 fm 2 . The B (Π 1 , 1 i π → 2 1 +) / B (Π 1 , 1 i π → 0 gs +) branching ratios in combination with the expected results from the Alaga rules demonstrate that K is a good approximative quantum number for 24 Mg. The use of the known ρ 2 (E 0 , 0 2 + → 0 gs +) strength and the measured B (M 1 , 1 + → 0 2 +) / B (M 1 , 1 + → 0 gs +) branching ratio of the 10.712 MeV 1 + level allows, in a two-state mixing model, an extraction of the difference Δ β 2 2 between the prolate ground-state structure and shape-coexisting superdeformed structure built upon the 6432-keV 0 2 + level. [ABSTRACT FROM AUTHOR]

The AGATA tracking detector array represents a significant improvement over previous Compton suppressed arrays. The construction of AGATA led to numerous technological breakthroughs in order to meet the requirements and the challenges of building a mobile detector across Europe. This paper focuses on the design and implementation of the data acquisition system responsible of the readout and control of the germanium detectors of AGATA. Our system is highly versatile, capable of instrumenting AGATA and seamlessly adapting it to various configurations with a wide range of ancillary detectors and/or spectrometers. It consists of three main components: an autonomous and independent infrastructure, a dedicated application core ensuring overall consistency, and a high-performance software package providing a fully integrated data flow management including the setting-up, the supervision and the slow control of the instrument. In this paper, we present a comprehensive analysis of the system's design and performance, particularly under high-counting rate conditions. [ABSTRACT FROM AUTHOR]

The article investigates the performance of germanium source doping-less tunnel FET (Ge DLTFET)-based digital integrated circuits. For this, the compact models have been developed for DLTFETs using Verilog-A approach. Furthermore, at circuit level, the performance of Ge DLTFET is compared with its conventional counterpart silicon source DLTFET (Si DLTEFT). Two digital benchmark circuits are considered for circuit simulation such as ring oscillator (RO) and conventional six-transistor static random-access memory (6 T SRAM). The simulation results depict that the operating frequency of Ge DLTFET RO is ~ 4.48 decade higher than Si DLTFET. Similarly, the performance of Ge DLTFET SRAM cell in terms of read and write delay is much better than its conventional counterpart Si DLTFET. Hence, Ge DLTFET can be considered as a promising device structure for high-speed digital circuit design and for its applications. [ABSTRACT FROM AUTHOR]

A software package for INAA (Instrumental Neutron Activation Analysis), developed at the Nuclear Metrology Laboratory of the IPEN-CNEN/SP, called k0-IPEN, is described. The package consists of a main program linked to nine subprograms designed to perform automatically most of the tasks necessary in order to obtain the mass fractions of the irradiated samples. External efficiency curves calculated by the Monte Carlo code MCNP6 can be read to extend the calibration curve to source to detector distances where only a few experimental points are available. Covariance analysis was used in all steps of the calculation. The validation of the code was tested in an intercomparison sponsored by the IAEA. [ABSTRACT FROM AUTHOR]

In order to establish the variation between results in mass fractions due to software implementation, as measured by the k0-method for INAA, the IAEA has organized a software intercomparison. A complete set of test spectra and associated information was assembled. Efficiency curves, neutron spectrum parameters, correction factors and mass fractions were calculated with the participating programs (k0-IPEN, k0-INRIM, k0-DALAT, k0-IAEA and KayWin) using identical peak areas. In this paper, we report on the observed discrepancies, causes, remedies and future software developments. The test data, as well as intermediate results and observed mass fractions of the certified reference material BCR-320R "channel sediment" are available through the IAEA on request. The variations in concentrations attributed to differences between the programs were initially found to be 5.6 and 7.9%, for certified and uncertified concentrations, respectively. After the certified concentrations had been made available to the participants and they had been allowed to improve their programs, the variations found were 2.7 and 3.4%, respectively. The main identified remaining causes of variation are differences in the procedures used for detector efficiency characterisation and neutron spectrum parameter determination. [ABSTRACT FROM AUTHOR]

This study investigates new technology for enhancing the sensitivity of low-mass dark matter detection by analyzing charge transport in a p-type germanium detector at 5.2 K. To achieve low-threshold detectors, precise calculations of the binding energies of dipole and cluster dipole states, as well as the cross sections of trapping affected by the electric field, are essential. The detector was operated in two modes: depleted at 77 K before cooling to 5.2 K and cooled directly to 5.2 K with various bias voltages. Our results indicate that the second mode produces lower binding energies and suggests different charge states under varying operating modes. Notably, our measurements of the dipole and cluster dipole state binding energies at zero fields were 8.716 ± 0.435 meV and 6.138 ± 0.308 meV, respectively. These findings have strong implications for the development of low-threshold detectors for detecting low-mass dark matter in the future. [ABSTRACT FROM AUTHOR]

Measurements of natural radioactivity in drinking water have been evaluated in most parts of the world to assess the dose rate and irradiation risk. This work aims to determine the natural radioactivity of bottled drinking water produced in Dire Dawa City and the surrounding area. Natural radioactivity water from nine different brandsis produced and commonly sold in bottles. The measurement was done by gamma-ray spectroscopy using a hyper-pure germanium detector. The water specific activity in 238U ranged from 2.91 ± 0.42 to 4.04 ± 0.42 Bq L-1; in 226Th, it ranged from 4.66 ±2.48 to 13.31 ± 0.2.48 Bq L-1, and in 40K, it ranged from 106. 52 ± 8.71 to 136.52 ± 8.71 Bq L-1. These results were compared with the reported values from other countries. Annual estimated effective doses from the intake of natural radionuclides in bottled drinking water were found to be below the limit of 0.1 mSv y-1 recommended by World Health Organization (WHO). The cumulative average annual effective doses of 238U for different age groups of (0 - 1), (1 - 2), (2 - 7), (7 - 12), (12 - 17) years, and above 17 years were estimated to be 3.01, 0.30, 0.60, 0.90, 2.88, and 0.66 mSv y-1, respectively. [ABSTRACT FROM AUTHOR]

Precise, highly reproducible control of the laser energy is required for high confidence laser–matter interaction research such as in dynamic compression science and high energy density physics. The energy must be adjustable without affecting the pulse shape (time varying intensity) or beam smoothness. We have developed a convenient two-stage energy tuning method for a nominal 100 J, 351 nm (UV) laser. The energy is adjusted in 10 J (10%) increments by operating the laser at full energy and inserting a beam splitter in the laser output. As the splitter is located after the final frequency tripling optics, the UV pulse shape is unchanged. The energy is varied by substituting a splitter of different reflectivity. For finer 3 J (3%) increments, the infrared pulse is attenuated inside the laser before the final amplifier. This requires modest tuning to preserve the pulse shape. The demonstrated variation in shot-to-shot reproducibility is less than +/−2.5 J (5% of the full energy), irrespective of the laser output energy. These approaches can be adapted to most ∼100 J class lasers. We describe these techniques and show two examples where they have elucidated the underlying physics in laser shock compression experiments. One used only the beam splitters to establish the pressure for melting in iron. The other combined both techniques to finely increment the peak stress (∼2 GPa steps) in germanium to precisely determine the onset and completion of melting—including the melting kinetics. These unambiguous results would not be possible without the developments described here. [ABSTRACT FROM AUTHOR]

To achieve more efficient and accurate measurement of low- and intermediate-level radioactive waste (LILW), a room-temperature semiconductor detector CdZnTe (CZT) can be used to replace the high-purity germanium detector. The traditional method cannot identify nuclides since the energy resolution of CZT detectors is poor, and the spectrum have more overlapping peaks, compared with HPGe detectors. Therefore, in this study, we proposed a gamma spectrum analysis method based on an intelligent dynamic library. Simulation spectrum experiment and standard-source spectrum experiment achieved LILW all-nuclide quantitative analysis based on a CZT detector for the first time globally. [ABSTRACT FROM AUTHOR]

We explore the possibility to use advanced germanium (Ge) detectors as a low-energy solar neutrino observatory by means of neutrino-nucleus elastic scattering. A Ge detector utilizing internal charge amplification for the charge carriers created by the ionization of impurities is a novel technology with experimental sensitivity for detecting low-energy solar neutrinos. Ge internal charge amplification (GeICA) detectors will amplify the charge carriers induced by neutrino interacting with Ge atoms through the emission of phonons. It is those phonons that will create charge carriers through the ionization of impurities to achieve an extremely low energy threshold of ∼0.01 eV. We demonstrate the phonon absorption, excitation, and ionization probability of impurities in a Ge detector with impurity levels of 3 × 1010 cm−3, 9 × 1010 cm−3, and 2 × 1011 cm−3. We present the sensitivity of such a Ge experiment for detecting solar neutrinos in the low-energy region. We show that, if GeICA technology becomes available, then a new opportunity arises to observe pp and 7Be solar neutrinos. Such a novel detector with only 1 kg of high-purity Ge will give ∼10 events per year for pp neutrinos and ∼5 events per year for 7Be neutrinos with a detection energy threshold of 0.01 eV. [ABSTRACT FROM AUTHOR]

Fish plays an essential role in Bangladesh people's diet, being the leading and sometimes easily replaceable food of low-income households. Major and minor elements in fish are crucial for the biological process in the human body. The analyses of 18 distinct elements (Na, Mg, Al, Ca, V, Cr, Mn, Fe, Cu, Zn, Se, Br, Rb, Sr, Cd, I, Pb) in 6 selected fishes consumed by the people who live in the Savar region of Dhaka city in Bangladesh were conducted. The objective of the present analysis is to assess the concentration of heavy and trace elements in these fishes and provide up-to-date information if these fishes are safe to eat. The Proton-Induced Gamma Emission technique and the High Purify Germanium detector were used to detect the characteristic Gamma-rays from the target and then calculate the concentration of elements. In general, the highest concentrations range was typically found in K, Ca, and Fe, while the lowest concentrations range were found in V, Cd, and Pb. The findings were compared with the allowable limits of the International Atomic Energy Agency (IAEA-407) and the World Health Organisation/Food and Agriculture Organization (WHO/FAO).Fish are a key source of protein for millions of Bangladeshi citizens, particularly households with low incomes, so monitoring the toxicity level of fish is very crucial. The present analysis results indicate that these fishes are not entirely free of health hazards in consumption. Further study will provide crucial information on the relationship between the concentration of elements and human health. [ABSTRACT FROM AUTHOR]

γ -ray spectroscopy of fission fragments is a powerful method for studies of nuclear structure properties. Recent results on the spectroscopy of fission fragments, using the combination of the AGATA γ -ray tracking array and the VAMOS++ large acceptance magnetic spectrometer at GANIL, are reported. A comparison of the performance of the large germanium detector arrays EXOGAM and AGATA illustrates the advances in γ -ray spectroscopy of fission fragments. Selected results are highlighted for prompt γ -ray spectroscopy studies, measurements of short lifetimes of excited states with the Recoil Distance Doppler-Shift method, using both AGATA and VAMOS++ and prompt-delayed γ -ray spectroscopy studies using AGATA, VAMOS++ and EXOGAM. [ABSTRACT FROM AUTHOR]

The AGATA collaboration has a long-standing leadership in the development of front-end electronics for high resolution γ -ray spectroscopy using large volume high purity germanium detectors. For two decades, the AGATA collaboration has been developing state-of-the-art digital electronics processing with high resolution sampling ADC, high-speed signal transfer and fast readout to a high throughput computing (HTC) farm for on-line pulse shape analysis. The collaboration is presently addressing the next challenge of equipping a 4 π array with more than 6000 channels in high resolution mode, generating approximately 10 MHz of total trigger requests, coupled to a large variety of complementary instruments. A next generation of front-end electronics, presently under design, is based on industrial products (System on Module FPGA's), has higher integration and lower power consumption. In this contribution, the conceptual design of the new electronics is presented. The results of the very first tests of the pre-production electronics are presented as well as future perspectives. [ABSTRACT FROM AUTHOR]

The EDELWEISS collaboration aims for direct detection of light dark matter using germanium cryogenic detectors with low threshold phonon sensor technologies and efficient charge readout designs. We describe here the development of Ge bolometers equipped with high impedance thermistors based on a NbxSi1−x TES alloy. High aspect ratio spiral designs allow the TES impedance to match with JFET or HEMT front-end amplifiers. We detail the behavior of the superconducting transition properties of these sensors and the detector optimization in terms of sensitivity to a-thermal phonons. We report preliminary results of a 200 g Ge detector that was calibrated using 71Ge activation by neutrons at the LSM underground laboratory. [ABSTRACT FROM AUTHOR]

The K-shell characteristic X-ray intensity ratios of nickel (II) oxide thin films generated by chemical spraying with 1-6 percent boron doping were studied. An americium-241 radioisotope source generated 59.543 kilo-electron volt gamma rays at 50 mili Curie intensity for these samples. The distinctive X-rays of the samples were calculated using a Canberra ultra-low energy germanium detector (with a resolution of 150 electron volts at 5.96 keV). The results were interpreted based on the amount of boron doped in nickel (II) oxide thin films, and it was discovered that, with the exception of boron doping quantities of 5 percent and 6 percent, K-shell X-ray intensity ratios rose as boron doping amounts increased. The findings are given and compared to those of the previous study. The obtained results are provided and compared in the table to the other researchers' theoretical and experimental results. [ABSTRACT FROM AUTHOR]

A new study of double beta decay processes in natural Zr isotopes using Zr metal samples and an ultra-low-background high-purity germanium detectors was performed at Laboratori Nazionali del Gran Sasso of INFN (Italy). Two data sets were collected with a 736.35 g and a 129.94 g Zr metal over 59.7 days and 37.3 days, respectively, and were used for a detailed analysis. A new limit on the double beta decay of 94 Zr to the 1st excited level of 94 Mo was set as T 1 / 2 β β > 2.1 × 10 20 year , which is a factor of three better than the previous result. It is shown that the current radiopurity of Zr metal (tens of Bq/kg), produced via two methods, do not comply with the radiopurity requirements for low-background experiments. Hence, we propose to use a purified ZrCl 4 powder in an optimized geometry as a new approach for future experiments with extended sensitivity focused on studies of rare nuclear processes in Zr isotopes. [ABSTRACT FROM AUTHOR]