Heavy Charged Particles Research Articles

Circuit Modeling of the Impact of Heavy Charged Particles on Transient Processes in Bipolar Analog Microcircuits

One of the factors causing the failure of spacecraft integrated circuits is exposure to heavy charged particles. The entry of heavy charged particles into electronic devices leads to the appearance of single event transients (short current pulses), which in analog microcircuits manifest themselves in distortion of the output signal shape, and in digital microcircuits can cause a single event upset. The article discusses a technique for circuit mode-ling of the effect of heavy charged particles on bipolar analog microcircuits, including the developed equivalent electrical circuit of a bipolar transistor for LTSpice and the procedure for modeling transient processes. Despite the simplifications adopted, namely: failure to take into account the dependence of the duration of the rise and fall of the current pulse generated by a charged particle on the parameters of the transistor structure, the assumption that the entire charge is generated in the active base and the space charge regions of the emitter and collector junctions, an equivalent circuit has been developed made it possible to determine that the shape of the collector current pulse for circuit with a common emitter when exposed to a heavy charged particle is determined by the speed of the transistor and its operating mode. Using the developed methodology, the “critical” transistors of the two studied analog microcircuits were determined, and the need to bypass the current-setting resistors with a small capacitor was justified.

Proton discrimination in CLYC for fast neutron spectroscopy

The Cs2LiYCl6:Ce (CLYC) elpasolite scintillator is known for its response to fast and thermal neutrons along with good γ-ray energy resolution. While the 35Cl(n,p) reaction has been identified as a potential means for CLYC-based fast neutron spectroscopy in the absence of time-of-flight (TOF), previous efforts to functionalize CLYC as a fast neutron spectrometer have been thwarted by the inability to isolate proton interactions from 6Li(n,α) and 35Cl(n,α) signals. This work introduces a new approach to particle discrimination in CLYC for fission spectrum neutrons using a multi-gate charge integration algorithm that provides excellent separation between protons and heavier charged particles. Neutron TOF data were collected using a 252Cf source, an array of EJ-309 organic liquid scintillators, and a 6Li-enriched CLYC scintillator outfitted with fast electronics. Modal waveforms were constructed corresponding to the different reaction channels, revealing significant differences in the pulse characteristics of protons and heavier charged particles at ultrafast, fast, and intermediate time scales. These findings informed the design of a pulse shape discrimination algorithm, which was validated using the TOF data. This study also proposes an iterative subtraction method to mitigate contributions from confounding reaction channels in proton and heavier charged particle pulse height spectra, opening the door for CLYC-based fast neutron and γ-ray spectroscopy while preserving sensitivity to thermal neutron capture signals.

Avoiding dust contamination by near-plasma chemical surface engineering

Dust contamination is a frequent problem when processing materials at the nanoscale by plasma technology. Various approaches have thus been applied to protect samples, however, requiring to adjust plasma properties which also imposes limitations on the process window. We therefore propose near-plasma chemical (NPC) surface engineering as a way to avoid dust contamination during and after plasma operation without altering the plasma environment by simply locating a polymeric mesh above the samples in the plasma sheath. Because of the electric potential acquired by the mesh, heavy charged particles cannot pass the open area of the mesh, avoiding their contact with the samples positioned below. Samples fabricated by NPC surface engineering are dust-free independently on the size or the origin of the powder nanoparticles. This neat approach can support many high-precision, dust-free applications of plasma technology on an industrial scale.

Technologies of modern radiotherapy and development prospects. Quality assurance concept

At the clinic of the N.N. Blokhin National Medical Research Center of Oncology has been using the following conformal irradiation technologies for cancer patients that meet international standards for more than 13 years: 3D conformal radio therapy (3DCRT); intensity modulated radiotherapy (IMRT); volume modulated arc therapy (VMAT); stereotactic radiation technique (SRT); radiotherapy technique with breathing control, total therapeutic irradiation (TRT) technique followed by bone marrow transplantation. The technological complex with which these technologies are implemented has demonstrated an increase in the quality of radiation treatment for cancer patients. However, despite the “advancement” of technology, there are limitations in the ability to reduce dose loads on critical organs for a number of nosologies. Therefore, the prospects for the development of radiotherapy in Russia lie in the creation of several clinical centers for the use of heavy charged particles that have different physical and dosimetric characteristics and, from this point of view, carry other opportunities and prospects. There is great interest in flash therapy.

A comprehensive analysis of interaction with charged particles of Rene alloys

In this research, the mass stopping powers, projected range, effective atomic numbers, effective electron density, radiation yield and stopping time of light and heavy charged particles such as electron, proton and alpha in the Rene alloys which consist of Rene N4, Rene N5, Rene 41, Rene 65, Rene 80, Rene 88, Rene 95 and Rene 104 were calculated for the first time. The calculations were performed by using the programs, which are called as ESTAR, SRIM and PAGEX codes. Moreover, all the results were compared with each other, and a comprehensive and comparative study of the theoretical results were presented.

ОЦЕНКА ЭФФЕКТИВНОСТИ ПРОБИОТИКА, ПОДВЕРГНУТОГО СОЧЕТАННОМУ ВОЗДЕЙСТВИЮ ТЯЖЕЛЫХ ЧАСТИЦ И ГИПОМАГНИТНОЙ СРЕДЫ, В ЭКСПЕРИМЕНТЕ С ВЫВЕШИВАНИЕМ КРЫС

A probiotic food subjected to a combined exposure to hypomagnetism and heavy charged particles was tested for the ability to counteract the negative effects of these spaceflight factors. The experiment was conducted with 36 male Wistar rats. The experimental group of animals (n=18) was tail-suspended for 21 days in order to experience a modeled hypogravity. Their controls were held in individual cages without suspension. Both groups were divided into 3 subgroups depending on which supplement they consumed, i.e. placebo, a probiotic food that had been or had not been exposed to proton radiation and hypomagnetism. As a result, it was established that suspension, as a stressor, causes reductions in the majority of intestinal protective microflora and that the preventive food levels the negative changes significantly. The number of lactobacilli in the suspended group fed with the probiotic food exposed to radiation and hypomagnetism remained unchanged throughout the experiment. This fact points to the stabilizing effect of the food on intestinal microflora. Effectiveness of the exposed food was close to that of usual.

7Be and 22Na radionuclides for a new therapy for cancer.

10B isotopes have been almost exclusively used in the neutron-capture radiation therapy (NCT) of cancer for decades. We have identified two other nuclides suitable for radiotherapy, which have ca. ten times larger cross section of absorption for neutrons and emit heavy charged particles. This would provide several key advantages for potential NCT, such as the possibility to use a lower nuclide concentration in the target tissues or a lower neutron irradiation flux. By detecting the characteristic γ radiation from the spontaneous decay of the radionuclides, one can image their biodistribution. These advantages could open up new possibilities for NCT applications as a safer and more efficient cancer therapy.

Radiation shielding features of Na2O–P2O5 glasses doped with MnO experimentally and using FLUKA and Phy-X

This research focused on examining the radiation shielding performance of (50% - x/2)P2O5-(50%-x/2)Na2O-xMnO (where x = 0, 5, 15, 25, and 33 mol%) glass system. The shielding review covered the radiation of photons, electrons, particles of heavy-charged, and neutrons. Hence, multiple parameters such as coefficient of mass attenuation (μm), transmission and buildup factors (HVL, MFP, EBF, and EABF), effective atomic number for samples (Zeff), and removal cross-section for fast neutron (FNRCS) of the selected samples were investigated. The results are determined experimentally and by employing FLUKA Monte Carlo software and Phy-X (ZeXTRA and PSD) theoretical programs. A relative discrepancy (RD) and a root-mean-square error (RMSE) were applied to verify the deviation between FLUKA and Phy-X values. An excellent agreement is noticed between measured, simulated, and calculated results. The research revealed that increasing MnO content improves the gamma, electron and heavy charged particle shielding efficiency of studied glasses. Although the addition of MnO has an insignificant impact on FNRCS (from 0.086 to 0.092 cm−1), obtained results identified the relationship between the packing density and shield ability against neutrons for ternary phosphate glasses. We found that the HVL values dropped from 13.898 cm to 11.568 cm at 15 MeV. A range of 7–12 for gamma, 8–12 for electron, 10–11 for proton, 10–11 for alpha, and 9–11 for carbon ion was the maximum value of Zeff that could be obtained. These glasses' shielding behaviors were contrasted with those of conventional materials. Accordingly, the sample with the highest mole fraction (x = 33 %) has higher shielding efficiency than ordinary concrete, Pyrex, and RS253-G18. Finally, the studied glass system can be a good compromise between highest effectiveness of shielding, lowest fabrication cost and environment-friendly shield.

On Production of Heavy Charged Particles in γγ Fusion at Planned pp Colliders

Production of heavy fermions in ultraperipheral collisions ($$pp \to p + \gamma \gamma + p \to p + {{\chi }^{ + }}{{\chi }^{ - }} + p$$) and the semi-exclusive reaction ($$pp \to p + \gamma \gamma {\text{*}} + X \to p + {{\chi }^{ + }}{{\chi }^{ - }} + X$$) is considered. Differential and total cross sections for the energies of the planned pp colliders are presented.

Modeling of heavy charged particle tracks overlap by pair of Al2O3:C, Mg dosimeters

Modeling of heavy charged particle tracks overlap by pair of Al2O3:C, Mg dosimeters

Effective field theory for the bound states and scattering of a heavy charged particle and a neutral atom

Effective field theory for the bound states and scattering of a heavy charged particle and a neutral atom

Simulated galactic cosmic ray exposure activates dose-dependent DNA repair response and down regulates glucosinolate pathways in arabidopsis seedlings.

Outside the protection of Earth's magnetic field, organisms are constantly exposed to space radiation consisting of energetic protons and other heavier charged particles. With the goal of crewed Mars exploration, the production of fresh food during long duration space missions is critical for meeting astronauts' nutritional and psychological needs. However, the biological effects of space radiation on plants have not been sufficiently investigated and characterized. To that end, 10-day-old Arabidopsis seedlings were exposed to simulated Galactic Cosmic Rays (GCR) and assessed for transcriptomic changes. The simulated GCR irradiation was carried out in the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Lab (BNL). The exposures were conducted acutely for two dose points at 40 cGy or 80 cGy, with sequential delivery of proton, helium, oxygen, silicon, and iron ions. Control and irradiated seedlings were then harvested and preserved in RNAlater at 3 hrs post irradiation. Total RNA was isolated for transcriptomic analyses using RNAseq. The data revealed that the transcriptomic responses were dose-dependent, with significant upregulation of DNA repair pathways and downregulation of glucosinolate biosynthetic pathways. Glucosinolates are important for plant pathogen defense and for the taste of a plant, which are both relevant to growing plants for spaceflight. These findings fill in knowledge gaps of how plants respond to radiation in beyond-Earth environments.

Quantification of the light output anistropy in deuterated stilbene

Deuterated stilbene is an organic scintillator that is a desirable material for fast neutron spectroscopy using spectrum unfolding techniques without requiring time-of-flight information. Due to the crystal structure of the material, some anisotropy of the light output exists, which is dependent on the direction of heavy charged particle recoil relative to the crystal structure. The anisotropy of trans-stilbene (hereafter referred to as stilbene) has been well characterized in previous work, but for deuterated stilbene, the anisotropy has only been partially characterized along the a and b crystal axes, while the artificial c′ axis, which shows the largest anisotropy in stilbene, has not been characterized until this publication. In this work, two deuterated stilbene crystals were characterized with neutron energies up to 35 MeV at the Los Alamos Neutron Science Center. For one of the crystals, the response is characterized along the a, b, and c′ axes. This characterization shows a distinct anisotropy along the axes in deuterated stilbene, which is very similar to that found in regular stilbene, such that the a axis is the brightest, while the b and c′ axes are approximately 3% and 20%–35% lower relative to the a axis.

Non-decreasing monotonic effects of cerium and gadolinium on tellurite glasses toward enhanced heavy-charged particle stopping: alpha-proton particles as major a part of cosmic radiation

Non-decreasing monotonic effects of cerium and gadolinium on tellurite glasses toward enhanced heavy-charged particle stopping: alpha-proton particles as major a part of cosmic radiation

Relative efficiency of radiophotoluminescent glass dosimeters in a scanning pencil proton beam

The increasing role of hadron therapy, and particularly of proton therapy, in cancer treatment requires dosimetric characterization of luminescent detectors in heavy charged particle beams. The ionization density, which is related to the linear energy transfer (LET), is changing when heavy charged particle is penetrating through a material. Therefore, it is crucial to evaluate how efficiency of the used dosimeters depends on the change in LET.The aim of this study was to evaluate relative efficiency of radiophotoluminescent (RPL) glass dosimeters (type GD-352M) in a clinical scanning pencil proton beam of 100 MeV and compare it to the results obtained with thermoluminescent (TL) dosimeters (type TLD-100). LETf and LETd at the selected dosimeter's position were evaluated and compared by two Monte Carlo codes (MCNP and PHITS). Linear dose response is precondition for the evaluation of dosimeter efficiency and first, dose response in proton beam was evaluated and compared with those in 60Co gamma ray field.Linear dose response up to 9 Gy was confirmed for RPLs in proton beam, and gamma ray field. For TLDs, supralinearity from about 5 Gy was observed. A constant relative efficiency is observed along the plateau (corresponding to LETf from 0.7 keV/μm to 1.7 keV/μm) of non-modulated proton beam with an average value 1.00 ± 0.02 for RPL and 0.97 ± 0.02 for TL dosimeters. Relative efficiency decrease of 10 % is observed for RPLs within the Bragg peak with LETf = 2.3 keV/μm. Future work will be focused on the evaluation of the efficiency for higher LET values using more energetic proton beams and precise positioning along the Bragg peak.

Combined Gamma-Rays and Carbon-12 Nuclei Irradiation Modulates Brain Chemokine and Cytokine Production and Improves Spatial Learning in Tau P301S, but not 5xFAD Mouse Line.

Earlier we showed the pro-cognitive effect of low doses of combined irradiation (including heavy charged particles) on Wistar rats. In the present work we studied the effect of irradiation (gamma-rays, 0.24Gy; carbon-12, 0.18 Gy, 400 MeV/nucleon) on the course of neurodegenerative process using TauP301S and 5xFAD transgenic mice lines, experimental models of Alzheimer's disease. Irradiation led to an increase in pro- and anti-inflammatory cytokines and chemokines (IL-2, IL-6, IL-10, KC) in Tau P301S mice, but not in 5xFAD. At the same time, only the Tau P301S line was found to exhibit radiation-induced improvement in spatial learning.

Exploring the KERMA, mass stopping power and projected range values against heavy-charged particles: A focusing study on Sm, Yb, and Nd reinforced tellurite glass shields

In present study, the behavior of ytterbium (III) oxide, samarium (III) oxide and neodymium (III) oxide reinforced novel TeO2–B2O3–V2O5 (TBV groups, tellurite-vanadium–boro) glasses groups are investigated against heavy charged particles, on mass stopping power, projected range and KERMA parameters. SRIM and PAGEX codes are used for determination of the mass stopping power, projected range and KERMA parameters in a kinetic energy range of 0–10 MeV. The highest KERMA values of TBV(X) glasses were achieved at 0.6 MeV. Among TBV(X) glasses, the TBVY1.5 sample with the highest material density (i.e. 5.01038 g/cm3) had the highest KERMA value. The TBVY1.5 sample has the lowest projected range values for alpha and protons with the same kinetic energy. The lowest values of mass stopping power were reported for the TBVY and TBVS groups, which had the highest density values among the analyzed glass samples. The TBVY1.5 sample provides the greatest stopping and slowing characteristics for alpha and proton kinetic energies ranging from 0 to 10 MeV. In this case, it can be said that these two glass groups may slow down alpha particles with a certain kinetic energy the most effectively. It can be concluded that TBV(Y) and TBV(S) glass groups might be useful for stopping the alpha, proton and electron particles.

MEASUREMENT OF THE CROSS SECTIONS FOR THE YIELD OF CHARACTERISTIC X-RAY RADIATION FROM 1-MeV PROTONS

This article presents the results obtained by measuring the characteristic x-ray production cross sections arising from the interaction of accelerated protons with the target atoms (PIXE). The PIXE production data were measured at the excitation of the K-, L-, and M-shells of target atoms in the mass range from Mg to Bi by 1 MeV protons. We use the approach based on the calculation of the PIXE production cross sections through the Rutherford backscattering cross section, which can be calculated from the Rutherford formula with high accuracy. This approach makes it possible to reduce the errors in measuring of the PIXE production cross sections and, thus, to improve the accuracy of the data obtained. Further, it is planned to expand the research area including protons of other energies and heavy charged particles in the energy range of 0.5–1.7 MeV/nucleon.

COMBINED GAMMA-RAYS AND CARBON-12 NUCLEI IRRADIATION MODULATES BRAIN CHEMOKINE AND CYTOKINE PRODUCTION AND IMPROVES SPATIAL LEARNING IN TAU P301S, BUT NOT 5xFAD MOUSE LINE

Earlier we showed the pro-cognitive effect of low doses of combined irradiation (including heavy charged particles) on Wistar rats. In the present work we studied the effect of irradiation (gamma-rays, 0.24 Gy; carbon-12, 0.18 Gy, 400 MeV/nucleon) on the course of neurodegenerative process using Tau P301S and 5xFAD transgenic mice lines, experimental models of Alzheimer’s disease. Irradiation led to an increase in pro- and anti-inflammatory cytokines and chemokines (IL-2, IL-6, IL-10, KC) in Tau P301S mice, but not in 5xFAD. At the same time, only the Tau P301S line was found to exhibit radiation-induced improvement in spatial learning.

Relative efficiency of radiophotoluminescent glass detectors in low energy ion beams

In heavy charged particle dosimetry, the luminescence efficiency strongly depends on linear energy transfer (LET) and characterization of the detectors' efficiency as a function of the particle LET is very important. Available literature data for the efficiency of radiophotoluminescent (RPL) glass detectors are scarce and especially for low energy range no data was found. In this study, detectors made of the most widely known RPL material (silver activated phosphate glass) were exposed to various low energy ion beams (1H, 7Li, and 12C). For every ion beam, the linear dose (fluence) response of the RPL glass detectors was confirmed for the investigated dose (fluence) range and the RPL efficiency relative to 60Co gamma rays was evaluated. The relative efficiency decreased as LET increased but not as a unique function of LET, where the relative efficiency (expressed for doses in RPL glass) decreased from 0.85 ± 0.06 for the 5 MeV 1H ion beam (LETw = 8.1 keV/μm) to 0.017 ± 0.001 for the 15 MeV 12C ion beam (LETw = 673.8 keV/μm). More experimental data are still needed but results obtained in this study may motivate the application and testing of microdosimetric models for RPL glass detectors.