Beta Isotopes Research Articles

Background ionizing radiation and semen parameters of men with reproductive problems.

The male reproductive system constitutes a set of tissues which are particularly sensitive to external factors. The aim of the study was to analyze the relationship between background radioactivity and the quality of the semen of the men who have reported to the infertility treatment facility in 2000-2016 in the Lublin region of eastern Poland. The radioactivity of the ground-level air layer obtained from the Institute of Meteorology and Water Management in Włodawa in the Lublin region was analysed. 4,250 spermiograms of patients who reported to the treatment facility for the first time due to infertility were analysed and correlated to background radioactivity in the Lublin region in 2000-2016. A long-term decrease in the percentage of morphologically normal spermatozoa of the patients was observed (r=-0.970; p<0.001 in 2000-2009 and r=-0.925; p=0.003 in 2010-2016). Men's age correlated negatively with sperm motility (r=-0.164; p=0.009) and morphology (r=-0.186; p=0.009). The percentage of spermatozoa with normal morphology was lowered by beta-isotopes of artificial origin in the air in 2000-2009 (r=-0.655; p=0.040) and by the exposure to gamma radiation of the ground-level atmosphere in 2010-2016 (r=-0.676; p=0.048). The percentage of sperm vitality was lowered by gamma radiation in the atmosphere (r=-0.636; p=0.006), but improved by beta isotopes in precipitation (r=0.686; p=0.002) in the whole of the analyzed period. The percentage of morphologically normal spermatozoa in patients who reported to the infertility treatment depends not only on the age of patient, but also on beta-isotopes of artificial origin and gamma radiation in the atmosphere. Beta isotopes in precipitation affect the improvement of sperm vitality.

Energy response of diamond sensor to beta radiation

This paper demonstrates the ability of diamond sensors to respond to beta radiation. A Chemical Vapor Deposition (CVD) single crystal diamond was used in this work. The diamond crystal has a dimension of 4.5×4.5 by 0.5 mm thick. Metal contacts were fabricated on both sides of the diamond using titanium and palladium metals with thicknesses of 50 nm and 150 nm, respectively. The energy response of the diamond sensor was experimentally measured using three beta isotopes that cover the entire range of beta energy: 147Pm, a weak beta radiation with a maximum energy of 0.225 MeV, 2°4Tl, a medium energy beta radiation with a maximum energy of 0.763 MeV, and 9°Sr/9°Y, with both a medium energy beta radiation with a maximum energy of 0.546 MeV, and a high energy beta radiation with a maximum energy of 2.274 MeV. The beta measurements indicate that diamond sensors are sensitive to beta radiation and are suitable for beta spectroscopy. This is important in estimating dose since diamond is tissue equivalent, and the absorbed dose is easily determined from the energy and the mass of the active volume. The high energy betas from 2°4Tl and 90Sr/90Y penetrates the sensor without depositing sufficient energy in the active area because their range is larger than the thickness of sensor. The sensitivity of the detector is limited because of its small volume and can be improved by combining smaller area sensors since growing large size diamond is currently a challenge.

C-14 beta converter

The study discusses the prospects for the development of low-voltage power supply sources. Beta isotope sources present great advantages for autonomous uninterrupted operation of remote devices, which gives an impulse to rapid development of betavoltaics. Silicon carbide homo- and hetero-structures serve as the isotope-based energy converters. We propose a new technology for isotope-based converter fabrication using silicon carbide and carbon-14 heterostructure as the active substance.

Analytical method for the determination of gross beta, 90Sr, 226Ra and Pu isotopes in environmental samples

This study presents analytical methods for the determination of gross beta, 90Sr, 226Ra and Pu isotopes using samples in the IAEA-TEL-2015-04 ALMERA Proficiency Test exercise. Samples for gross beta were prepared by evaporation and then analyzed using a gas proportional counter. 90Sr in the liquid sample was concentrated as SrCO3 precipitates and purified by Sr resin. Pu isotopes and 90Sr in the soil sample were extracted from the sample by mineral acid leaching and separated using TEVA and Sr resin, respectively. Pu isotopes were determined by alpha spectrometry and 90Sr were determined with a liquid scintillation counter. Radium in the soil sample was extracted by LiBO2 fusion, and the radon-emanation method using LSC was applied for the determination of 226Ra.

Dose assessment of bremsstrahlung induced by beta-emitting radioisotopes of uranium-238 series and lead in human tissues

In the natural uranium-238 decay series, pure beta isotopes such as 234Th, 234Pa, 214Pb, 214Bi, 210Pb and 210Bi are released. The few lead isotopes such as 211Pb, 212Pb, 213Pb and 215Pb are good beta emitters. In certain nuclear reactions of reactor these isotopes are released. These beta isotopes have maximum beta energies, which induce the bremsstrahlung radiation. The bremsstrahlung component of these beta isotopes has been traditionally ignored in dosimetry calculations. The shapes of bremsstrahlung spectra are a basic ingredient in the understanding and quantification of beta-ray dosimetry. The bremsstrahlung spectra produced by these high-energy isotopes such as 234Th, 234Pa, 214Pb, 214Bi, 210Pb, 210Bi, 211Pb, 212Pb, 213Pb and 215Pb in bone, muscle and teeth are studied, and the computed spectral distributions are presented. The spectral shapes are primarily responsible for variations in the shapes of depth–dose distributions. They are intended to provide a quick and convenient reference for spectral shapes and to give an indication of the wide variation in these shapes. The evaluated beta bremsstrahlung dose as a function distance for the studied nuclides is also presented. The efficiency, intensity and dose rate of bremsstrahlung induced by beta isotopes of natural uranium-238 decay series and beta-emitting lead isotopes in human tissues such as brain, breast, heart, kidney, liver, muscle, pancreas and bone have also been studied in the present investigation. The values of bremsstrahlung dosimetric parameters are low for pancreas, but they are high for bone. For all studied tissues these parameters are high for 234Pa, but low for 210Pb.

Rejection of α-particle background for neutrinoless double beta decay search with pixel detectors

Experiments searching for the neutrinoless double beta decay require a very low level of background. Most experiments aim for a background rate of about 10−4 to 10−3events/kg ·keV ·yr. α-particles can be an important part of the background since they occur as decay products of many isotopes in the natural decay chains. They are emitted with kinetic energies of a few MeV and therefore produce background at the Q-value of most double beta isotopes. In this publication we demonstrate experimentally that α-particle background can be reduced by about six orders of magnitude exploiting its topology of triggered pixels which is different from neutrinoless double beta decay of 116Cd.

The NEMO-3 Experiment

The NEMO-3 (Neutrino Ettore Majorana Observatory) experiment, located in the Modane Underground Laboratory, is currently searching for neutrinoless double beta decay (0νββ). The experiment has been taking data since 2003 with seven double beta isotopes and is scheduled to complete data acquisition in late 2010. Two neutrino double beta decay (2νββ) results for the main isotopes (7 kg of 100Mo and 1 kg of 82Se), new results for 150Nd, as well as results for 96Zr, 48Ca, 130Te and 116Cd are presented. NEMO-3 uses a unique technique that allows for the in situ measurement of background contamination. No evidence for neutrinoless double beta decay has been found to date. The data are also interpreted in terms of alternative models such as weak right-handed currents and Majoron emission.

An Apparatus to Search for Neutrinoless Double Beta Decay

Abstract The NEMO-3 (Neutrino Ettore Majorana Observatory) experiment, located in the Modane Underground Laboratory, searches for neutrinoless double beta decay. The experiment has been taking data since 2003 with seven double beta isotopes and completed data acquisition in January 2011. Two neutrino double beta decay results for the main isotopes (7 kg of 100 Mo and 1 kg of 82 Se), new results for 150 Nd and 130 Te, as well as results for 96 Zr and 48 Ca are presented. NEMO-3 uses a unique technique that allows for the in situ measurement of background contamination. No evidence for neutrinoless double beta decay has been found to date. The data are also interpreted in terms of alternative models such as weak right-handed currents and Majoron emission. In this proceeding, I discussed the measurements made with NEMO-3 and discussed the status, research and design of the next generation experiment, SuperNEMO.

Neutrinoless double beta decay

The search for neutrinoless double beta decay is the only practical way to test whether neutrinos are Majorana or Dirac particles. The next generation of experiments aim to probe the effective Majorana neutrino mass down to few 10 meV, as predicted by oscillation experiments in case of the inverse mass hierarchy. According to recent nuclear matrix calculations, the predicted decay rates per mass of double beta isotope are varying within a factor of few when comparing them within the same theoretical model framework. The sensitivity of the upcoming experiments depend therefore primarily on the available mass of double beta isotopes and the experimental conditions. In particular, the achievable background suppression and the detection efficiency will be decisive for their success.

Dosimetry study for -radiation treatment of in-stent restenosis

Intravascular brachytherapy (IVBT) has been recognised as a treatment modality for reducing coronary restenosis after angioplasty and stent-implantation procedures. For the treatment of in-stent restenosis using beta-emitter (188)Re, delivering adequate doses to the entire vessel wall is not possible without the potential of overdosing tissues. A method to measure the dose distribution, perturbation and percentage depth dose using plane-parallel and cylindrical tissue-equivalent phantoms has been developed. Good agreement was found between experimental results and Monte Carlo simulation performed using MCNP4C code. The dose given to the affected area in the vascular region for intravascular radiation treatment was 15-30 Gy. Dose inhomogeneity beyond the stent surface decreased significantly with increasing radial distance. In the region close to the stent outer surface (>0.5-mm radial distance), a dose reduction of 11-17% due to the stent was observed. However, the dose perturbations due to the physical properties of metallic stents were found to be significant in IVBT for in-stent restenosis by using measured dose profiles in phantoms. The method can provide accuracy in beta isotope in vivo dosimetry results for treatments involving short-range dose distributions and provide a relatively high-level spatial resolution for detection.

A search for various double beta decay modes of Cd, Te, and Zn isotopes

Various double beta decay modes of Cd, Zn, and Te isotopes are explored with the help of CdTe and CdZnTe semiconductor detectors. The data set is splitted in an energy range below 1 MeV having a statistics of 134.5 g d and one above 1 MeV resulting in 532 g d. No signals were observed in all channels under investigation. New improved limits for the neutrinoless double beta decay of 70Zn of T 1/2>1.3×10 16 yrs (90% CL), the longest standing limit of all double beta isotopes, and 0 νβ +EC of 120Te of T 1/2>2.2×10 16 yrs (90% CL) are given. For the first time a limit on the half-life of the 2 νECEC of 120Te of T 1/2>9.4×10 15 yrs (90% CL) is obtained. In addition, limits on 2 νECEC for ground state transitions of 106Cd, 108Cd, and 64Zn are improved. The obtained results even under rough background conditions show the reliability of CdTe semiconductor detectors for rare nuclear decay searches.

Microcalorimeter measurements

The technique of calorimetric beta spectroscopy with Low Temperature Detectors (LTD) has been applied recently to the electron anti-neutrino mass search experiments. The best suited beta isotope for a calorimetric measurement is 187 Re, which is characterized by the lowest known end-point energy, about 2.5 keV. The experiments with 187 Re are designed in order to realize the “total energy dispersive beta spectroscopy”, that is sensitive to all the energy emissions of the beta decay, except that of the emitted anti-neutrino. This specific feature allows us to avoid the model dependent correction for the atomic and molecular final states, which are conversely applied in the electron impulse beta spectroscopy of Tritium. For the first time, a limit of 26 eV/c 2 (95% CL) to the anti-neutrino mass is obtained from high statistics spectra of 187 Re that are measured with this technique. In addition, the high accuracy of the actual measurements has remarkably increased our knowledge of the beta decay of this isotope. Currently three groups are engaged in different rhenium experiments. I present some historical hints and the main features of these experiments, the current status and the results.

Brachytherapy: Savior or Tease

Dating from the inception of percutaneous coronary angioplasty, restenosis has been the postprocedural Achilles heel. Despite a decade of research, with a myriad of mechanical devices and pharmacologic agents, this vexing problem has yet to be resolved. Although intracoronary stents have proved effective at restenosis reduction, they have yet to achieve an acceptable level and, in some cases, remain resistant to any treatment. Intracoronary radiation using gamma or beta isotopes, has generated tremendous excitement with promising results. Indeed, the SCRIPPS (Scripps Coronary Radiation to Inhibit Proliferation Post Stenting) trial, which employed gamma radiation, showed a statistically significant reduction in restenosis in a small patient population. Further studies with a variety of isotopes and delivery modalities are currently underway, bringing with them their own assemblage of issues.

The effect of scintillation pulse shape on the photomultiplier response curve

The photomultiplier tube (PM tube) used e.g. in scintillation counting is normally not a perfect light detector and therefore has individual response characteristics. As liquid scintillation counters are becoming more widely used as scintillation spectrometers, it is very important to understand how the PM tube behaves under different conditions. Among other things, we have noticed that the pulse height response, i.e. the electrical charge at the output in response to a certain illumination intensity on the cathode, not only varies between batches of PM tubes, but is also dependent on the shape of the scintillation pulse.One problem with PM tubes is that the response will not be linear when the illumination flux (i.e. number of photons reaching the cathode per unit time) exceeds a certain level. This can easily happen because scintillation pulses produced by a radioactive decay in a scintillation liquid are composed of two parts, a prompt part and a delayed part, and most of the photons produced are emitted in the prompt part. The width of the prompt part is typically below 5 ns, while the delayed part may extend up to several μs. When measuring a beta isotope with higher energy than 14C or any alpha isotope the intensity of the prompt part alone may exceed this critical level resulting in distortion in the pulse height distribution, or spectrum. This effect must also be taken into account when using an external standard for accurate quench determination and correction.In this report we describe the equipment used and measurements of the response curve for a number of photomultiplier tubes with different light sources.

Aspects of radioanalytical chemistry

A review is presented of recent progress in the more traditional techniques for radiochemical analysis, including solvent extraction, ion exchange and ion chromatography together with some isotope detection methods. Prominent in the detection studies are liquid scintillation spectrometry and its associated sample preparations. Less familiar approaches are also considered, for example, high-performance liquid chromatography of beta isotopes and inductively coupled plasma mass spectrometry.

Solid state counting system for high energy beta and gamma decay isotopes

The disclosure relates to a method and apparatus for quantitatively evaluating radiation emissions of radiolabeled laboratory samples. These radiation emissions frequently include high energy beta and gamma radiation emissions resulting from 32 P isotope decay. High energy beta and gamma radiation is detected by a solid state PIN photodiode and analyzed by a microprocessor to provide an indication of a radiation emission characteristic such as activity expressed in disintegrations per minute (DPM). An indication of sample activity is obtained from a detected sample count rate adjusted by a detector calibration constant which is determined by the microprocessor from a reference radiation emitting sample of known activity and volume. Indications of radiation emission characteristics may be displayed by an alpha-numeric liquid crystal display. Hard copy data may be produced from an expansion module in the form of a printer module adapted to receive data input from the microprocessor. Another expansion module, a high performance liquid chromatography (HPLC) flow detector, provides indications of radiation emissions of a sample flow passing through the flow detector. Radiation emission characteristics obtained from the sample flow may be printed by the printer module or displayed by the alpha-numeric liquid crystal display.