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A common advanced radiochemical technique is the use of the AG® 1-X8 anion exchanger, Cl2− form (from Bio Rad), to separate uranium and/or thorium from a sample by ion exchange. This method is used to separate elements by chemical elution from an ion exchange column via a precipitate of substances (co-precipitation), with Nd3+ as a thin layer of smooth fluoride particles on a membrane filter, then using α-spectrometry to measure uranium and thorium. The obtained data showed that the column could be reused, at least twelve times, safely in separating uranium and thorium from environmental samples, before observing any change in the performance of the exchanger.

A method that does not require changing wire screens is proposed to achieve continuous measurement of unattached radon progeny. This method uses cumulative activity functions to deduct the influence of previous measurements from the current measurements on the sampling wire screen. The continuous measurement method was compared with a single measurement method, including relative deviations, uncertainties, and fluctuation range, which indicated the effectiveness of the cumulative activity functions applied to the continuous measurement method. The establishment of a continuous measurement method based on alpha spectroscopy provides technical support for the monitoring device.

The estimation of radioactivity level is vital for population health risk assessment and geological point of view and can be evaluated as rate of exhalation and source concentration (226Ra, 232Th and 40K). The present study deals with the soil samples for investigation of radionuclides content and exhalation rates of radon –thoron gas from different sites in northern Haryana, India. Absorbed dose and associated index estimated in the present study are the measures of environmental radioactivity to inhalation dose. Effective doses received by different tissues and organs by considering different occupancy and conditions are also measured. Exhalation rates of radon and thoron are measured with active scintillation monitors based on alpha spectroscopy namely scintillation radon (SRM) and thoron (STM) monitors respectively. Sample height was optimized before measurement of thoron exhalation rate using STM. Average values of radon and thoron exhalation are found 16.6 ± 0.7 mBqkg−1h−1 and 132.1 ± 2.6 mBqm−2s−1 respectively. Also, a simple approach was also adopted, to evaluate the thoron exhalation which accomplished a lot of challenges, the results are compared with the data obtained experimentally. The study is useful in the nationwide mapping of radon and thoron exhalation rates for understanding the environmental radioactivity status.

This article discusses outcome of research for deriving a methodology and apparatus for ascertaining for the presence of ultratrace-level actinides in air from their alpha emission signatures, while remaining blind to the relatively large (1000× higher activity) alpha emissions from Rn-progeny. Apparatus and techniques were developed to collect and characterize alpha-emitting nuclides of Rn-progeny and actinides in air on a polycarbonate 3 μm pore size continuous air monitor (CAM) filter. A wet-chemistry approach was developed and validated for successfully separating the Rn-progeny alpha emitting isotopes of Po-214 and Po-218, while extracting the actinides (U, Pu, Am) in a fluid mixture that is suitable for conduct of alpha spectroscopy with a centrifugally tensioned metastable fluid detector (CTMFD). The resulting α-TMFD technology was compared against the state-of-art “Alpha-Sentry™” Continuous Air Monitor (CAM) system commonly utilized world-wide. Results indicate that the α-TMFD technology can potentially offer complementary and superior performance in multiple performance categories, and ∼18× improvement in the time to detect (e.g., at 0.02 derived air concentration (DAC) within ∼3 h, versus ∼70 h for Alpha-Sentry) for actinides of interest while also remaining ∼100% blind to ∼103× higher Rn-progeny background—with the added potential for offering few keV scale energy resolution without resorting to peak shape fitting, versus ∼300–400 keV for existing CAM systems.

The bioassay of urine and fecal samples has been used since the 1940s to determine an individual's uptake of uranium and actinide elements such as americium and plutonium. Over the years, several analytical separation methods and techniques have been employed for these types of analyses. Analytical separations, ranging from solvent extraction and anion exchange to chromatography, and analytical techniques, ranging from autoradiography to kinetic phosphorescence to fission-track analysis and high-resolution solid-state alpha spectroscopy, have been used at one time or another. Over the last few decades, there have been significant advances in radiochemical separations, as well as an increased use of mass spectroscopy, to determine trace and ultratrace levels of actinides in urine and fecal samples. This review summarizes and discusses developments in radiochemical separation methods and advancements in analytical techniques for actinide bioassay since the early 1940s to the present, followed by a recent development and trend in the bioassay of actinides-particularly in urine and fecal samples.

Here we report the first spectroscopic alpha particle detection based on CsPbBr 3 detectors with asymmetric contacts. The CsPbBr3 single crystal was grown from the melt using Bridgman method and then fabricated into detectors with different contacts. The In/CsPbBr 3/Au detector presented a low dark current density ( ∼ 100 nA/cm2 ) and temporal stable performance under high electric field (1000 V/cm). Such detector demonstrated excellent gamma ray resolving capability with a full-width at half maximum (FWHM) of ∼ 5.9 keV for the 57Co 122 keV γ ray. The CsPbBr3 detector was capable of simultaneously resolving both the alpha particle (5.5 MeV) and γ ray (59.5 keV) peaks from 241Am radioactive isotope. The transport properties of CsPbBr3 were then determined based on the alpha particle spectra and corresponding rise time distributions. The equivalent values of electron and hole mobilities were indicated as 63 and 49 cm2/(V ⋅ s) respectively. The calculated electron and hole mobility-lifetime products were 4.5 × 10−4 and 9.5 × 10−4 cm2/V, respectively, demonstrating superior transport properties of holes over electrons in CsPbBr3 . This work widens the scope of perovskite detectors to encompass charged radiation as well as high energy X/ γ rays, and will significantly promote and guide further studies on perovskite materials for radiation detection applications.

This study is intended to assess the natural radioactivity in the drinking water in the southern region of Lebanon and to determine its suitability for human consumption. In this context, activity concentrations for gross alpha, gross beta, 238U, 234U, and radon from selected drinking water sources, wells, and springs and the corresponding tap water, in the area under investigation, were determined during both the wet and the dry seasons. The maximum recorded activities of gross alpha, gross beta, and radon measured using liquid scintillation counter were found to be 374.6 ± 11.5 mBq L−1 for gross alpha, 418 ± 12 mBq L−1 for gross beta, and 42,900 ± 370 mBq L−1 for radon. Whereas, alpha spectroscopy analysis for uranium content showed maximum activities of 53.7 ± 2.1 mBq L−1 for 238U and 55.9 ± 2.3 mBq L−1 for 234U. Significant seasonal activity variation between wet and dry season was noticed only in gross alpha concentrations. In addition, significant variation between sources and tap water was recorded only in radon concentrations. Whereas, no significant variation was noted in radioactivity concentrations in waters from springs and those from wells. In contrast to all sampled locations, the annual effective dose of only one sampled well (Aitaroun) exceeded the WHO individual dose criterion (IDC) level of 100 µSv year−1 and recorded an annual effective dose of 170 µSv year−1, 103 µSv year−1, and 127 µSv year−1 for infants, children, and adults, respectively.

Optimization algorithms are applied to resolve the second-order pileup (SOP) issue from high counting rates occurring in digital alpha spectroscopy. These are antlion optimizer (ALO) and particle swarm optimization (PSO) algorithms. Both optimization algorithms are coupled to one of the three proposed peak finder algorithms. Three custom time-domain algorithms are proposed for retrieving SOP peaks, namely peak seek, slope tangent, and fast array algorithms. In addition, an average combinational algorithm is applied. The time occurrence of the retrieved peaks is tested for an elimination of illusive pulses. Conventional methods are inaccurate and time-consuming. ALO and PSO optimizations are used for the localization of retrieved peaks. Optimum cost values that achieve the best fitness values are demonstrated. Thus, the optimum positions of the detected peak heights are achieved. Evaluation metrics of the optimized algorithms and their influences on the retrieved peaks parameters are established. Comparisons among such algorithms are investigated, and the algorithms are inspected in terms of their computational time and average error. The peak seek algorithm achieves the lowest average computational error for pulse parameters (amplitude and position). However, the fast array algorithm introduces the largest average error for pulse parameters. In addition, the peak seek algorithm coupled with an ALO or PSO algorithm is observed to realize a better performance in terms of the optimum cost and computational time. By contrast, the performance of the peak seek recovery algorithm is improved using the PSO. Furthermore, the computational time of the peak optimization using the PSO is much better than that of the ALO algorithm. As a final conclusion, the accuracy of the peaks detected by the PSO surpasses that for the peaks detected by the ALO. The implemented peak retrieval algorithms are validated through a comparison with experimental results from previous studies. The proposed algorithms achieve a notable precision for compensation of the SOP peaks within the alpha ray spectroscopy at a high counting rate.

The chapter begins with a description of inorganic crystal scintillators and their properties, and the mechanisms of scintillation in inorganic crystals. This leads to a description of the various components of the solid scintillation analyzer including the crystal detector, photomultipliers, pulse height discriminators, and single- and multichannel analyzers. The general concepts and principles of solid scintillation analysis are described including gamma-ray spectra, counting and detection efficiencies, activity determinations, self-absorption, counting geometry, spectral resolution, and background measurements. Automated methods of solid scintillation analysis are described including automated gamma analysis and microplate scintillation techniques. Included is a treatment of the scintillation process in plastic media and the application of plastic scintillators to radionuclide analysis. The chapter also provides a comprehensive treatment on the measurement of neutrons with inorganic scintillators, solid organic neutron scintillators, and neutron detectors with scintillating and optical fiber. Neutron/gamma pulse shape discrimination and Bonner sphere neutron spectrometry are included in detailed discussions on the measurement of neutrons with solid scintillators. Current principles and practice in the application of the Lucas cell for the measurement of 222 Rn are included. Advances in the development of phoswich detectors are described for the simultaneous detection and measurement of alpha, beta, and gamma rays and neutrons, low-level counters, the simultaneous measurement of neutron/gamma/proton fields, and simultaneous beta- and gamma-spectroscopy. Other state-of-the-art applications of inorganic crystal scintillators described in the chapter include neutrino detectors, the detection and measurement of double beta ( ββ ) decay, and the use of scintillating bolometers for the search for neutrinoless double beta (0 νββ ) decay and the search for weakly interacting massive particles (WIMPs).

In this paper we compare suitability of three different semi-insulating bulk silicon carbide (SiC) materials for fabrication of radiation detectors. We prepared planar sensors with various metal contact combination and characterized detector quality by the alpha spectroscopy and I-V characteristic measurements. We observed that 4H-SiC material from the II-VI company is not suitable for radiation detector fabrication due to high concentration of vanadium doping. We also present a poor charge collection efficiency of the 4H-SiC Norstel material due to high concentration of residual impurities and we evaluated low mobility-lifetime product (alpha)= 3.5E-7 cm2/V from the alpha spectroscopy. We demonstrate that the 4H-SiC material from the Cree company is the best candidate for the production of radiation detectors. We evaluated mobility-lifetime product (alpha)= 5.4E-6 cm2/V using AuTi/SiC/TiAu contact structure.

Direct measurements of radiation signatures can be utilized as a key functional component to verify a country’s commitments in a transparency agreement. Special nuclear material comprises isotopes of uranium and plutonium, where each has unique signatures that differentiate it from the other isotopes when measured with radiation detection equipment. Depending on the type of confirmatory information desired, a wide range of radiation detection methods are available including several nondestructive methods of gamma spectroscopy, neutron and gamma counting, multiplicity counting, and imaging, and some destructive methods of alpha spectroscopy and mass spectrometry. Each method provides information indicative of material composition, isotopic composition, or processing method where radiation detection equipment is often utilized in the laboratory and field to perform these analyses. This chapter aims to provide a brief introduction to the radiation signatures of interest for radiation detection, an overview of how these signatures are utilized for standard radiation detection-based verification techniques utilized in non-proliferation and arms control monitoring and verification, as well as a description of some of the challenges associated with implementation of these techniques into international agreements.

Two kinds of measuring methods were described for the determination of Plutonium-241 in low level wastes in this study. Plutonium isotopes were separated and purified by highly selective UTEVA and TRU resin. LSC, alpha spectrometry, and ICP-MS were applied and compared for determination of Plutonium-241. There is a good agreement with the analytical results and also shows that the different analytical methods have high chemical recovery yields.

Alpha spectroscopy chamber backgrounds are routinely measured using blank plates. Operator time spent moving blank plates in and out of chambers is significant. If chamber backgrounds are measured in empty chambers, time spent moving blank plates can be reclaimed for other uses. This study compares results of chamber backgrounds measured with and without plates. Five hundred fourteen chamber backgrounds measured with plates are paired with 514 chamber backgrounds measured without plates. The total counts within 13 spectral regions of interest are compared statistically. Chamber backgrounds measured without blank plates are found statistically equivalent to chamber backgrounds measured with blank plates.

Alpha spectrometry is used for qualitative and quantitative analysis of actinides in biological and environmental samples. This technique requires a thin, homogenous and carrier-free deposit. Numerous methods for source preparation are electrolytic deposition, spontaneous deposition, micro-precipitation, direct evaporation, vacuum sublimation, etc. The most widely used method for preparation of actinides for alpha spectrometry is electro-deposition of actinides onto a stainless steel planchette. This procedure is time consuming, requires elaborate equipment and is expensive. Micro-precipitation method on the other hand is comparatively faster and more reliable. Thus, the present study was taken-up to optimize various parameters for rapid alpha source preparation of actinides by micro-precipitation method.

GaAs Schottky barrier detectors for α particle spectrometry have been tested. Detectors had an input window area of 80 mm2 and a working barrier layer thickness of 40–50 μm. The energy resolution (FWHM) measured on 5.499 MeV α line of 238Pu source amounted to 17.5 keV at a generator peak width of 7.8 keV. In the measurements on a 226Ra source, detectors showed linear response and nearly 100% charge collection efficiency at reverse bias above 65 V for all energies of α particles emitted from the source. Tests for thermal stability showed that the proposed detectors can be used in alpha-spectrometry of radionuclides at temperatures up to 120°C.

In this work, we present and describe the program ALPHACAL, specifically developed for the calibration of alpha-particle sources. It is therefore more user-friendly and less time-consuming than multipurpose codes developed for a wide range of applications. The program is based on the recently developed code AlfaMC, which simulates specifically the transport of alpha particles. Both cylindrical and point sources mounted on the surface of polished backings can be simulated, as is the convention in experimental measurements of alpha-particle sources. In addition to the efficiency calculation and determination of the backscattering coefficient, some additional tools are available to the user, like the visualization of energy spectrum, use of energy cut-off or low-energy tail corrections. ALPHACAL has been implemented in C++ language using QT library, so it is available for Windows, MacOs and Linux platforms. It is free and can be provided under request to the authors.

This contribution describes a rapid, fieldable alpha spectroscopy sample preparation technique that minimizes consumables and decreases the nuclear forensics timeline. Functional ultrafiltration membranes are presented that selectively concentrate uranium directly from pH 6 groundwater and serve as the alpha spectroscopy substrate. Membranes were prepared by ultraviolet grafting of uranium-selective polymer chains from the membrane surface. Membranes were characterized by Fourier-transform infrared spectroscopy before and after modification to support functionalization. Membrane performance was evaluated using uranium-233 or depleted uranium in both deionized and simulated groundwater at pH 6. Functionalized membranes achieved peak energy resolutions of 31 ± 2 keV and recoveries of 81 ± 4% when prepared directly from pH 6 simulated groundwater. For simulated groundwater spiked with depleted uranium, baseline energy resolution was achieved for both isotopes (uranium-238 and uranium-234). The porous, uranium-selective substrate designs can process liters per hour of uranium-contaminated groundwater using low-pressure (

Structured illumination microscopy (SIM) for the imaging of alpha particle tracks in fluorescent nuclear track detectors (FNTD) was evaluated and compared to confocal laser scanning microscopy (CLSM). FNTDs were irradiated with an external alpha source and imaged using both methodologies. SIM imaging resulted in improved resolution, without increase in scan time. Alpha particle energy estimation based on the track length, direction and intensity produced results in good agreement with the expected alpha particle energy distribution. A pronounced difference was seen in the spatial scattering of alpha particles in the detectors, where SIM showed an almost 50% reduction compared to CLSM. The improved resolution of SIM allows for more detailed studies of the tracks induced by ionising particles. The combination of SIM and FNTDs for alpha radiation paves the way for affordable and fast alpha spectroscopy and dosimetry. Journal compilation

The paper contains a description of a method for the analysis of the complex alpha spectra generated during the measurement of the activity of filters outside of a vacuum chamber under environmental conditions. The peaks corresponding to the energies of alpha particles emitted by the specific isotopes are particularly large on the low-energy side of the peak maximum, and the energy resolution strongly depended on the applied filters. The analysis was based on the non-linear regression to a function designed for four, six and eight parameters. Satisfactory results were obtained for each of these functions, and the best-fitting results were achieved for the eight-parameter function. In addition, the uncertainties related to the estimated parameters, as well as the signals corresponding to functions that describe the shape of the energy peak, have been evaluated. There are also examples of the implementation of the method with respect to short-lived radon progeny and thoron decay products.

This work presents a new technique for discriminating between alpha particles of different energy levels. In a first study, two groups of alpha particles emitted from radium-226 and americium-241 sources were successfully separated using a CR-39 microfilm of appropriate thickness. This thickness was adjusted by chemical etching before and after irradiation so that lower-energy particles were stopped within the detector, while higher-energy particles were revealed on the back side of the detector. The number of tracks on the front side of the microfilm represented all alpha particles incident on that side from the two sources. However, the number of tracks on the back side of the microfilm represented only the long-range alpha particles of higher energy that arrived at that side. Therefore, by subtracting the number of tracks on the back side from the number of tracks on the front side, one could easily determine the number of tracks for the short-range alpha particles of lower energy that remained embedded in the microfilm. Discrimination of the two energy levels is thus achieved in a simple, fast, and reliable process.

The YAlO 3 :Ce scintillation crystal has excellent mechanical properties and is not affected if used in chemically aggressive environments. The detector with the diameter of Φ25.4 mm and thickness of 0.1 mm was coupled with the PMT, associated electronics and the MCA in order to study its alpha spectroscopy properties. The measured alpha spectra of the surface calibration sources of 241 Am and 230 Th were compared with results of a Monte Carlo simulation. The experiment and the simulation were carried out for three distances between the detector and the surface alpha source in order to assess the effect of the distance on the detected energy of alpha radiation. Finally, the detector was used for the monitoring of radon ( 222 Rn) decay products (radon daughters) in the air. It was concluded that the detector is suitable for the in-situ alpha spectroscopy monitoring under ambient atmospheric conditions. Nevertheless, in order to identify radionuclides and their activity from the measured alpha spectra a computer code would need to be developed.

Here, we present the fabrication details and functional tests of diamond-based α-spectroscopic sensors, dedicated for high-temperature experiments, targeting the chemistry of transactinide elements. Direct heating studies with this sensor material, revealed a current upper temperature threshold for a safe α-spectroscopic operation of T det = 453 K . Up to this temperature, the diamond sensor could be operated in a stable manner over long time periods of the order of days. A satisfying resolution of ≈ 50 keV FWHM was maintained throughout all conducted measurements. However, exceeding the mentioned temperature limit led to a pronounced spectroscopic degradation in the range of 453 − 473 K , thereby preventing any further α-spectroscopic application. These findings are in full agreement with available literature data. The presented detector development generally enables the chemical investigation of more short-lived and less volatile transactinide elements and their compounds, yet unreachable with the currently employed silicon-based solid state sensors. In a second part, the design, construction, and α-spectroscopic performance of a 4-segmented diamond detector, dedicated and used for transactinide element research, is given as an application example.

Occupational exposure to plutonium is generally monitored through analysis of urine samples. Typically, plutonium is separated from the sample and other actinides, and the concentration is determined using alpha spectroscopy. Current methods for separations and analysis are lengthy and require long count times. A new method for monitoring occupational exposure levels of plutonium has been developed, which requires fewer steps and overall less time than the alpha spectroscopy method. In this method, the urine is acidified, and a Pu internal standard is added. The urine is digested in a microwave oven, and plutonium is separated using an Eichrom TRU Resin column. The plutonium is eluted, and the eluant is injected directly into the Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). Compared to a direct "dilute and shoot" method, a 30-fold improvement in sensitivity is achieved. This method was validated by analyzing several batches of spiked samples. Based on these analyses, a combined standard uncertainty plot, which relates uncertainty to concentration, was produced. The MDA95 was calculated to be 7.0 × 10 μg L, and the Lc95 was calculated to be 3.5 × 10 μg L for this method.

Negative-ion neutral-beam injection (NNBI) is an important source of heating and current drive for next-step fusion devices where the injected energy can range from hundreds of keV to 1 MeV. Few diagnostics are suitable for phase-space resolved measurements of fast ions with energy in excess of 100 keV. A study to assess the feasibility of fast-ion deuterium-alpha (FIDA) spectroscopy to diagnose high-energy ions produced by NNBI is presented. Case studies with the Large Helical Device (LHD) and JT-60SA illustrate possible solutions for the measurement. The distribution function of fast ions produced by NNBI is calculated for both devices, and the FIDA spectrum is predicted by synthetic diagnostic simulation. Results with 180 keV NNBI in LHD show that, with a judicious choice of viewing geometry, the FIDA intensity is comparable to that obtained with the existing FIDA system. The measurement is more challenging with the 500 keV NNBI in JT-60SA. Simulations predict the FIDA intensity to be about 1% of the background bremsstrahlung, which is small compared to existing FIDA implementations with positive neutral-beam injection where signal levels are an order of magnitude larger. The sampling time required to extract the small FIDA signal is determined using a probabilistic approach. Results indicate that long averaging periods, from ones to tens of seconds, are needed to resolve the FIDA signal in JT-60SA. These long averaging times are suitable in long-pulse (∼100 s), steady-state devices like JT-60SA where an important measurement objective is the spatial profile of the slowing-down distribution of fast ions.

Radioactivity dispersed in indoor environment is a consequence of exhalation of radioactive gas radon from soil, building materials, and rocks containing primordial radionuclide. The health risk for population from the radionuclides and radon exhalation rates of soils from different places in vicinity of Kurukshetra in Northern India is estimated. Radionuclides content and radon exhalation rate of the soil samples are measured using gamma and alpha spectroscopy, respectively. Various doses (absorbed gamma dose and annual effective dose) and associated index (Alpha, Gamma, External, and Internal Radiation Hazard Indices) with radionuclide contents present in soil samples are also estimated. Radiological hazards are calculated by two different approaches; one based on radionuclides content and emanation factor and other on the basis of exhalation rates and room dimensions. The results of radioactivity content and exhalation rates are found below the level recommended by United Nation Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Alpha equivalent dose (HE) is also estimated as per the recommendations of UNSCEAR and found well below the safe limit. The study is helpful to determine the soil potential to exhale carcinogenic gas radon at the surface and also for radon and thoron mapping.

An intercomparison experiment of three radon progeny measurement methods, based on alpha spectrometry (Kerr method), alpha–beta spectrometry and liquid scintillation counter (LSC method), was carried out in the standard radon chamber at NIM. Both the consistency and the uncertainty analysis of three different methods were studied in detail. Results show that, at the EEC level of 4000 Bq/m3, the uncertainties of the alpha–beta spectrometry, LSC method and Kerr method were 3.78%, 6.41% and 9.46%, respectively, which are mainly contributed by detection efficiency uncertainty, measuring time uncertainty and counting statistical uncertainty in sequence. The comparison results at different concentration levels show that the measurement values of three methods are consistent within the error range of 3%. The alpha–beta spectrometry can be used as a reference standard method to achieve the simultaneous measurement of RaA, RaB, RaC concentrations and EEC in the radon chamber.

A semi – integrating method and its implementation for spectroscopy measurement of radon activity in air is presented. No filters and electric field collection of the progeny are used. The realized device allows relatively quick and accurate determination of low radon concentrations both indoors and at open air. The device implementing the method can be used for other radon associated measurements as well as an ordinary alpha spectroscopy system.

Charged Particle Detectors of different sizes suitable for high resolution alpha spectroscopy have been designed and developed successfully in Bharat Electronics Limited. The electrical characteristics of the devices show close agreement with the designed values. The stringent requirements of high breakdown voltage and low leakage current have been fulfilled by making necessary modification to the standard process and device design.

MLLTRAP is a double Penning-trap designed for high precision mass measurements of exotic nuclei. It was built and commissioned off-line at the Maier-Leibnitz Laboratory (MLL) in Garching and is currently installed at the ALTO facility at IPNO, awaiting online commissioning. A complementary double-trap assembly dedicated to in-trap decay spectroscopy is being studied, in which the central electrode of the second trap has been replaced by an arrangement of four silicon-strip detectors (SSD) set at the trapping potential. By using the well-known buffer-gas cooling technique in the first trap we will be able to deliver a spot-like ion cloud of high purity to the detector trap. The decay products being emitted in-flight and not from an implantation material, we expect to achieve high-resolution decay spectroscopy of the confined ion bunch. In the case of heavy α emitters, α particles can be detected by the in-trap SSD, while conversion electrons are guided very efficiently by the magnetic field to another detector, thus allowing for unperturbed detection of both. In addition, once coupled with a position-sensitive electron detector, this spectroscopic trap will allow for indirect measurements of excited-state lifetimes in the region of heavy and super-heavy nuclei, via a new recoil distance measurement method.

In this work, the fabrication, electrical characterization and alpha spectral characterization of single-crystal (SC) diamond bulk radiation detector have been carried out. The performance metrics of the SC-diamond bulk detector such as the leakage current density, charge collection efficiency, spectral resolution and polarization effects are studied and are compared with a bulk detector fabricated using High-Pure Semi-Insulating (HPSI) 4H-SiC. It is found that the SC-diamond detector exhibits lower leakage current density, higher μτ product, better spectral resolution and no polarization effects in comparison to the HPSI 4H-SiC detector. The time response analysis of the SC-diamond detector is carried out to study the effect of alpha particles on the operation of the SC-diamond detector. Accordingly, the stability of the SC-diamond detector is tested by evaluating the total counts versus real time and the performance of the diamond detector is found to be stable during the alpha-time spectroscopy. Hence, diamond bulk detectors using commercially available electronic grade diamond may be better suited for alpha particle spectroscopy compared to HPSI 4H-SiC of nearly equivalent thickness.

The direct disposal of municipal solid waste such as nappies to the environment may create serious pollution problems. Based on the circular economy and waste management concepts, the conversion of nappies and/or their ingredients (such as super absorbent polymer (SAP)) to high added value products is of great importance. In this work, a modified SAP (MSAP) was examined as an adsorbent for treatment of contaminated waters and uranium recovery. Batch experiments and spectroscopic techniques were used to examine the effect of various parameters (pH, contact time, temperature, initial concentration, and ionic strength), and the mechanism of adsorption U(VI) and desorption process. The U(VI) concentration was determined by alpha spectroscopy after addition of 232U standard tracer solution to account for possible interferences during electrodeposition and alpha particle counting. The maximum adsorption monolayer capacity was found to be 217.4 mg/g at pH 4.0 and at 298 K. The adsorption of U(VI) on MSAP seems to occur mainly via the formation of inner-sphere surface complexes between U(VI) and the carboxylic surface moieties of MSAP. The MSAP could satisfactorily be regenerated with 0.1 M Na2CO3 (>90%) and it also shows a promising applicability to real wastewaters contaminated with U(VI).

A theoretical and experimental investigation of Bragg's rule in low energy loss region where charge exchange straggling can be ignored is presented. Energy-loss straggling of 5.486 MeV alpha particles in air and 5N purity constituent gases was measured using high-resolution alpha spectroscopy system. Measured values are compared with Bohr, Bethe-Livingston and Yang et al. formulations. An experimental investigation of Bragg's rule to estimate the energy-loss straggling in air using the experimental data of constituents is discussed.

Alpha spectroscopy can be used to quantify actinide (e.g., U, Pu) concentration in a molten salt electrorefining environment. One could electroplate actinide samples directly onto a semiconductor alpha particle detector to obtain representative isotopic concentrations from a measured alpha particle energy spectrum. In this work, we fabricated a SiC Schottky device that can be partially biased to a depletion depth of 8.8 µm that is able to measure the energy spectrum of 4.012 MeV alpha particles emitted from a thorium film with a thickness. We also present a method in calculating the thickness of a medium thick alpha source with a dE/dx detector.

A technique to determine the isotopic constituents of a mixed actinide sample has been proposed by a coincident alpha-conversion electron measurement. This presents a unique signature to allow the unfolding of isotopes that possess overlapping alpha particle energy and reduce backgrounds of an unseparated sample. The work presented here are results of conversion electron spectroscopy of 241 Am, 238 Pu and 239 Pu using a dual-stage peltier-cooled 25 mm 2 silicon drift detector and alpha spectroscopy with a passivated ion implanted planar silicon detector. The conversion electron spectra were evaluated from 20–55 keV based on fits to the dominant conversion electron emissions, which allowed the relative conversion electron emission intensities to be determined. These measurements provide crucial singles spectral information and calibration to aid in the coincident measurement approach. Furthermore, an alpha-conversion electron spectrometer was assembled using the silicon based detectors described and results of a coincident spectrum analysis is reported for 241 Am.

A new electronic radon/thoron monitor employing semiconductor detectors based on a passive diffusion chamber design has been recently developed at the Helmholtz Zentrum Munchen (HMGU). This device allows for acquisition of alpha particle energy spectra, in order to distinguish alpha particles originating from radon and radon progeny decays, as well as those originating from thoron and its progeny decays. A Monte-Carlo application is described which uses the Geant4 toolkit to simulate these alpha particle spectra. Reasonable agreement between measured and simulated spectra were obtained for both 220 Rn and 222 Rn , in the energy range between 1 and 10 MeV. Measured calibration factors could be reproduced by the simulation, given the uncertainties involved in the measurement and simulation. The simulated alpha particle spectra can now be used to interpret spectra measured in mixed radon/thoron atmospheres. The results agreed well with measurements performed in both radon and thoron gas environments. It is concluded that the developed simulation allows for an accurate prediction of calibration factors and alpha particle energy spectra.

Alpha spectrometry has been employed for the determination of the atom ratios of low enriched uranium samples. WinALPHA was used for the deconvolution and tail correction of the alpha spectra. The atom ratios calculated from alpha spectrometry were compared with that obtained by thermal ionisation mass spectrometry. The results are in good agreement and is encouraging. The tail correction methodology WinALPHA is shown to be applicable for deconvoluting when the alpha activity of high energy peak is more than 45 times the lower energy peaks for obtaining the correct alpha activity ratio which is very challenging and been done for the first time.

Using calculations and SRIM simulations of alpha particle energy spectroscopy, we show that it may be possible to determine the birth energies and concentrations of alpha-emitting radioisotopes from in situ measurements in fluid-filled rectangular microchannels. We quantify the effect of microchannel geometry on the alpha spectrum by comparing results for planar source volumes and rectangular microchannels. By reducing the dimensions of the microchannel, the contribution to the spectrum from low count rate, low energy radioisotopes may be revealed amongst the signal from higher count rate and higher energy alpha emitters.

Activity concentration of uranium isotopes (238U, 234U and 235U) were analyzed in drinking and surface water samples collected in the vicinity of the WIPP site using alpha spectroscopy. The purpose of this study was to investigate the changes in uranium concentrations (if any) in the vicinity of the WIPP site and whether the February 14, 2014 radiation release event at the WIPP had any detectable impact on the water bodies around the WIPP.

The European Union published in 2013 a new Drinking Water Directive with stricter requirements for measuring natural radioactivity. In order to adhere to this, a method for sequential separation of 210Pb, 210Po, 238U and 234U in drinking water was applied using UTEVA® and Sr resins. Polonium-210, 238U and 234U were quantified using alpha-particle spectrometry and 210Pb using liquid scintillation counting. Radium-226 and 228Ra were determined using 3M Empore Radium RAD Disks, and their quantification was done using a Quantulus™ 1220 liquid scintillation counter.

We present here energy straggling data for alpha particles from 241Am in air and its constituents, and an experimental investigation of Bragg’s rule. High resolution alpha spectroscopy system from ORTEC with an ultra-thin source, an ion implanted thin entrance window detector of small diameter, and state of the art counting electronics with a 4096 MCA is used. In the controlled experimental environment gases of 5N purity are used to measure energy straggling. Measured values are compared with the theoretical predictions of Bohr, Bethe-Livingston, Titeica and Yang et. al. An experimental investigation on using Bragg’s rule to estimate the energy straggling in air from the experimental obtained data of constituents is presented.

The purpose of this article is to describe the method used to determine the amount of 148Gd produced in the (α,γ) activation of enriched 144Sm samples. Advanced simulations are fitted to data to help constrain systematic uncertainties. The simulations are complimented with RBS measurements of the samples.

In this present study, a color contrast approach was proposed to find a method for quantify uncertainty in alpha particle spectroscopy using nuclear track detectors (NTDs). According to this method, this color contrast approach was applied to NTDs as an alpha particle spectrometer. A comparison between the registration of 4.0 MeV alpha particles by Makrofol®DE1-1 and CR-39 NTDs using a color contrast method was carried out in alpha spectroscopy. The contrast of the alpha tracks of each single color channel whether red, green and blue resulting from split RGB image was determined. The measurements were proved that green color channel produced the highest contrast of the alpha tracks of about 85%, in both Makrofol® DE1-1 and CR-39 NTDs. The results of 4.0 MeV alpha particle etch-pits diameters in Makrofol® DE1-1 didn't show homogenous diameters for short etching time. The standard deviation of 4.0 MeV alpha-track diameters in Makrofol® DE1-1 went up to a maximum value of 2.23 μm at a removal thickness of 12.25 μm. When increasing the etching time, they decreased sharply to about 1.18 ± 0.02 μm at a ratio of change 0.047 that was less than 6%. The standard deviation of 4.0 MeV alpha particle etch-pit diameters in CR-39 detector was linearly correlated with the removal thickness at a ratio of change of 0.02 which was less than 5%. Results revealed that the etch-pit diameter in Makrofol® DE1-1detector, in alpha particle spectrometry was best measured around the end of the alpha particle range. Results of this study are discussed within the frame work of nuclear track formation theories and etching mechanism in nuclear track detectors (NTDs).

Deposition of $^{222}Rn$ daughters onto detector materials pose a risk to ultra-low background experiments. To mitigate this risk, a common approach is to enclose detector components in sealed plastic bags made of films known to be effective barriers against radon. We describe a new method to evaluate radon barriers which is unique in that (a) it gauges not only the intrinsic resistance to radon penetration of a plastic film but also the integrity of bags fabricated from the film and sealed following some protocol, and (b) it employs gamma spectroscopy rather than alpha spectroscopy. We report the results of applying this method to sealed bags fabricated from polypropylene, Nylon, Mylar, metallized Mylar, FEP, and PFA. Evaluation of the fluoropolymers FEP and PFA as radon barriers are the first such measurements., Comment: 16 pages, 5 figures, 4 tables

This paper describes the physics, design, and qualification of a novel, parallel-processing mode spectroscopy enabled sensor system architecture for the detection of fundamental nuclear particles interacting with fluids placed under tensioned metastable states. Our past studies have described gamma-blind spectroscopic detection of neutrons, alphas and fission events using the Centrifugally Tensioned Metastable Fluid Detectors (CTMFDs) allowing for high intrinsic efficiencies over 80% for neutron energies spanning 0.02eV to 15 MeV, and efficiencies of over 95% for detection of alpha and fission fragment recoils. As a novel advancement, the CTMFD was radically redesigned such that a single unit effectively works as several detectors operating in parallel — resulting in the Multi-Arm Centrifugally Tensioned Metastable Fluid Detectors (MAC-TMFDs). The MAC-TMFD now enables benefits such as several times faster data acquisition, and simultaneous, more rapid spectroscopic detection of neutrons-alphas-fission events within the same apparatus. As a first-of-kind prototype, the dual-arm, aka (2)MAC-TMFD effectively encompassing two TMFDs within one form factor has been designed, constructed and extensively tested for neutron-alpha detection. The MAC-TMFD was tested to show improvement over traditional liquid scintillation counters (LCSs) for alpha spectroscopy and exhibited ∼ 10-to-100 times greater efficiency than a Beckman LS6500 T M spectrometer. Gamma-insensitivity was demonstrated using Co-60 and Cs-137 sources (offering gamma ray exposure doses of up to ∼ 1 R/h (0.01 Sv/h) while showing high sensitivity for neutron detection [for hard Pu–Be(n, α ), and fission 252Cf fission derived neutron spectra; this is in addition to allow for energy profile difference identification. Analysis for neutron detection efficiency reveals that the detection efficiency varies non-linearly with the tension negative pressure (Pneg) ranging from 10% to over 50% of the theoretical interaction rates for the Pneg states tested. The resulting detection data has been shown to remain compatible with the underlying science and physics of a traditional TMFD system; however, with a 0.1 MPa reduced Pneg offset attributed to the tension state being maximized at the wall–fluid interface for the MAC-TMFD vs. in the bulk for the conventional CTMFD design. A follow-on (8)MAC-TMFD architecture (with 8 independent CTMFDs within a single enclosure) has also been constructed and proven promising in scoping studies. This paper presents the various steps involved in consideration of the underlying physics, technical challenges, design, construction, and benchmarking-vetting of the MAC-TMFD sensor architecture.