Proton Energy Range Research Articles

Measurement of the tensor analyzing power for the γd → ppπ− reaction in the low energy range of protons

All three components of the tensor analyzing power for the reaction of [Formula: see text]-meson photoproduction on a deuteron have been measured in photon energy range of 280–500[Formula: see text]MeV and proton energy range of 15–70[Formula: see text]MeV. The experiment has been conducted on an internal tensor-polarized deuterium gas target of the VEPP-3 electron storage ring using the method of detecting two final protons in coincidence. Measured components of the tensor analyzing power have been compared with calculations results obtained within the framework of diagrammatic approach.

Measurement of production cross sections in proton induced reactions on natural zirconium

The production cross sections of 90g,92m,95gNb, 86,88,89g,95Zr, 86g,87m,87g,88Y, 85gSr, and 83Rb in a proton induced nuclear reaction of natural zirconium were measured within the proton energy range of 35.7–66.6 MeV at the Korea Multi-purpose Accelerator Complex (KOMAC), Gyeongju, Korea. The excitation functions of radionuclides produced from the natZr(p,x) reactions were determined through a stacked-foil activation method and an off-line γ-ray spectroscopy. A high purity germanium (HPGe) detector was used to measure the induced activities of the radionuclides. The incident beam energy in each foil was calculated from the SRIM code. The proton flux was determined by using the natCu(p,x)62Zn monitor reaction. The measured data were compared with the experimental data in the literature and the data from the TENDL-2017 library based on the TALYS code. The present results are in general agreement with the literature data and in some cases with the calculated data from the TENDL-2017 library. However, in some of the cases, the calculated data from the TENDL-2017 library overestimate or underestimate the experimental data.

Results on radiation tolerance of diamond detectors

In sight of the luminosity increase of the High Luminosity-LHC (HL-LHC), most experiments at the CERN Large Hadron Collider (LHC) are planning upgrades for their innermost layers in the next 5–10 years. These upgrades will require more radiation tolerant technologies than exist today. Usage of Chemical Vapor Deposition (CVD) diamond as detector material is one of the potentially interesting technologies for the upgrade. CVD diamond has been used extensively in the beam condition monitors of BaBar, Belle, CDF and all LHC experiments. Measurements of the radiation tolerance of the highest quality polycrystalline CVD material for a range of proton energies, pions and neutrons obtained with this material are presented. In addition, new results on the evolution of various semiconductor parameters as a function of the dose rate are described.

Proton light yield in organic scintillators using a double time-of-flight technique

Recent progress in the development of novel organic scintillators necessitates modern characterization capabilities. As the primary means of energy deposition by neutrons in these materials is n-p elastic scattering, knowledge of the proton light yield is paramount. This work establishes a new model-independent method to continuously measure the proton light yield in organic scintillators over a broad energy range. Using a deuteron breakup neutron source at the 88-in. Cyclotron at Lawrence Berkeley National Laboratory and an array of organic scintillators, the proton light yield of EJ-301 and EJ-309, commercially available organic liquid scintillators from Eljen Technology, was measured via a double time-of-flight technique. The light yield was determined using a kinematically over-constrained system in the proton energy range of 1–20 MeV. The effect of the pulse integration length on the magnitude and shape of the proton light yield relation was also explored. This work enables accurate simulation of the performance of advanced neutron detectors and supports the development of next-generation neutron imaging systems.

Determination of Ne20(p,γ)Na21 cross sections from Ep=500−2000keV

Background: The reaction $^{20}\mathrm{Ne}(p,\ensuremath{\gamma})^{21}\mathrm{Na}$ influences the nucleosynthesis of Ne, Na, and Mg isotopes while contributing to hydrogen burning in several stellar sites, such as red giants, asymptotic giant branch (AGB) stars, massive stars, and oxygen-neon (ONe) novae. In the relevant temperature range for these environments ($T$ = 0.05--0.5 GK), the main contributions to this reaction rate are from the direct capture process as well as the high-energy tail of a subthreshold resonance in the ground-state transition at ${E}_{x}$ = 2425 keV in the $^{21}\mathrm{Na}$ compound nucleus.Purpose: The previous measurement of this reaction reports cross sections with large uncertainties for the ground-state transition. At higher energies, where the subthreshold resonance makes a smaller contribution to the total cross section, only upper limits are provided. This work aims to reduce the uncertainty in the cross section where direct capture dominates, as well as provide cross-section data in previously unmeasured regions.Method: The $^{20}\mathrm{Ne}(p,\ensuremath{\gamma})^{21}\mathrm{Na}$ reaction was measured over a wide proton energy range (${E}_{p}$ = 0.5--2.0 MeV) at ${\ensuremath{\theta}}_{\text{lab}}$ = ${90}^{\ensuremath{\circ}}$. Transitions to the ground state and to the 332 and 2425 keV excited states were observed. The primary transitions to these three bound states were utilized in an $R$-matrix analysis to determine the contributions of the direct capture and the subthreshold resonance to the total cross section.Results: The cross sections of the present measurements have been found to be in good agreement with the previous data at low energy. Significantly improved cross-section measurements have been obtained over the ${E}_{p}$ = 1300--1900 keV region. The narrow resonance at ${E}_{\text{c.m.}}$ = 1113 $\mathrm{keV}({E}_{x}$ = 3544.3 keV) has also been remeasured and its strength has been found to be in good agreement with previous measurements.Conclusions: An extrapolation of the $S$ factor of $^{20}\mathrm{Ne}(p,\ensuremath{\gamma})^{21}\mathrm{Na}$ has been made to low energies using the $R$-matrix fit. The reaction rate from the subthreshold resonance was found to be the main contributor to the reaction rate at temperatures below about 0.1 GK. The present rate is lower in the temperature range of interest than those presented in current reaction rate libraries by up to 20%.

Proton-induced activation cross section measurement for aluminum with proton energy range from 0.4 to 3 GeV at J-PARC

ABSTRACT We have started an experimental program to measure activation cross sections systematically in the proton-induced spallation reaction in structural materials commonly used in high-intensity proton accelerator-based facilities, such as Japan Proton Accelerator Research Complex (J-PARC). As the first step of the program, aluminum (Al) was chosen to verify the adequacy of the measurement technique implemented in a J-PARC proton beam environment because data of Al have been relatively well studied both by experimental measurement and simulation. Activation cross sections of 7Be, 22Na, and 24Na in Al were measured at proton energy points from 0.4, 1.3, 2.2 to 3.0 GeV, which could be delivered smoothly from the synchrotron. The validity of experimental data has been verified by introducing an effective proton numbers determination procedure. We compared the measured data with existing experimental data, the evaluated data (JENDL-HE/2007), and the calculations with several intra-nuclear cascade models by the Particle and Heavy Ion Transport code System (PHITS) code. Although the experimental data agreed with JENDL-HE/2007, the calculations underestimated about 40%. This could come from the evaporation model (generalized evaporation model) being implemented in the PHITS code. We found that the calculations agreed with the experimental data by an upgraded PHITS code.

Measurement of excitation functions and analysis of isomeric population in some reactions induced by proton on natural indium at low energy

The excitation functions for reaction residues populated via In115(p,p)115mIn, In115(p,pn)114mIn, In115(p,p2n)113mIn, In113(p,p)113mIn, In115(p,nα)111mCd, In115(p,3n)113Sn and In113(p,n)113Sn channels were measured over the proton energy range of 8–22 MeV using stacked foil activation technique. Theoretical analysis of the data were performed within the framework of two statistical model codes EMPIRE-3.2 and TALYS-1.8. Isomeric cross section ratio for isomeric pairs Inm,g115, Inm,g114, Inm,g113, S113nm,g and Cdm,g111 were determined for the first time. The dependence of isomeric cross section ratio on various factors are analysed.

L shell X-ray production cross sections for Sr and Mo by proton impact

Total L X-ray production cross sections were measured for Sr and Mo by proton impact. Proton energies ranged from 200 keV to 3 MeV. K shell cross sections of Ti and Cu samples were obtained in order to normalize our results, bearing in mind that for those elements the cross sections have been vastly measured and modeled. The cross sections were obtained using the thick sample method and the results showed general agreement in the range of energies studied. The results obtained here for Sr and Mo are in well agreement with those predicted by the ECPSSR theory in the 500–3000 keV proton energy range. In the case of Sr and proton energies lower than 500 keV, the experimental results do not agree well to the calculated with ECPSSR, differing by values greater than 30%. This discrepancy may be due to an overstimation of the stopping power in oxides or secondary emissions that are not negligible in this energy range. All measured spectra were fitted by a novel open software for PIXE semi-quantitative analysis that take into account several physical phenomena related to X-ray production, absorption and detection.

10B/11B isotopic ratio and atomic composition of boron carbide: Determination by proton induced γ-ray emission and proton elastic backscattering spectrometry

The 10B/11B isotopic ratio and the atomic composition of boron carbide, an important non-metallic ceramic, have been determined non-destructively by the particle induced γ-ray emission (PIGE) and elastic backscattering spectrometry (EBS) techniques with proton beams. The analysis has been performed on powder as well as sintered ceramics containing boron in natural or 10B enriched composition. The PIGE technique, performed at a 4.0–4.2MeV proton energy, utilizes the 10B(p,αγ)7Be, 10B(p,p′γ)10B and 11B(p, p′γ)11B nuclear reactions for (a) the isotopic analysis of boron and (b) the determination of total boron, and the 13C(p,p′γ)13C nuclear reaction for the determination of carbon. The irradiation conditions were optimized by determining the thick targets yields of prompt γ-rays, characteristic of these reactions, in the 3.0–4.2MeV proton energy range. The quantitative analysis was performed by comparison with standards taking into account the attenuation of γ-rays in the specimens. The uncertainty in the determination of the 10B/11B isotopic ratio and the B/C atomic ratio is about 2% and about 5% respectively. The analysis by EBS, on the other hand, involves the 10B(p,p)10B, 11B(p,p)11B and 12C(p,p)12C elastic scatterings at the 2.0MeV proton energy. This method too yields satisfactory results. Between the two, PIGE is the method of choice for bulk analysis while EBS is useful in discerning compositional variations in surface regions.

Energy Production Demonstrator and Material Testing Station optimization for Megawatt proton beams

A simulation study of the Energy Production Demonstrator (EPD) concept – a solid heavy metal target irradiated by GeV-range intense proton beams and producing more energy than consuming – is carried out. Neutron production, fission, energy deposition, energy gain, testing volume and helium production are simulated using the MARS15 code for tungsten, thorium, and natural uranium targets in the proton energy range 0.5–120GeV. This study shows that the proton energy range of 2–4GeV is optimal for both a natU EPD and the tungsten-based testing station for proton accelerator facilities. Simulation-based conservative estimates not including breeding and fission of plutonium suggest the proton beam current sufficient to produce 1GW of thermal output power with the natU EPD while supplying a relatively small fraction of that power to operate the accelerator. The thermal analysis has been performed and has shown that the EPD with a parallel proton beam feeding the core has a potential problem due to a possible core meltdown. A scheme has been proposed with a beam steering on the outer surface of the target; its thermal analysis indicates that slicing the target in shorter parts and maintaining a temperature of 25°C on their surfaces would to avoid the target meltdown.

Measurement of [formula omitted] reaction cross-section within the proton energy range of 3.38 to 19.63 MeV

The Fe58(p,n)Co58 reaction cross-section within Giant Dipole Resonance (GDR) region i.e. from 3.38 to 19.63 MeV was measured by stacked-foil activation and off-line γ-ray spectrometric technique using the BARC-TIFR Pelletron facility at Mumbai. The present data were compared with the existing literature data and found to be in good agreement. The Fe58(p,n)Co58 reaction cross-section as a function of proton energy was also theoretically calculated by using the computer code TALYS-1.8 and found to be in good agreement, which shows the validity of the TALYS-1.8 program.

Quantitative analysis of Li by PIGE technique

In this work, the cross section of the reactions 7Li(p,pγ)7Li (γ – 478keV) at the proton energy range 2.0–4.2MeV was measured. The measurements were carried out at the 3MV Tandem Accelerator at the CTN/IST Laboratory in Lisbon. To validate the obtained results, calculated gamma-ray yields were compared, at several proton energy values, with experimental yields for thick samples made of inorganic compounds containing lithium. In order to quantify the light elements present in the samples, we used a standard free method for PIGE in thick samples, based on a code – Emitted Radiation Yield Analysis (ERYA), which integrates the nuclear reaction excitation function along the depth of the sample. We also demonstrated the capacity of the technique for analysis of Li ores, as Spodumene, Lithium Muscovite and Holmquistite, and Li-alloys for plasma facing materials showing that this is a reliable and accurate method for PIGE analysis of Li in thick samples.

Optimization of breeding properties of the spallation neutron source target for ADS

One of the main components of an ADS (accelerator-driven reactor systems) is the spallation target, generating neutrons for power plant. Neutrons are generated due in spallation reactions induced on heavy nuclei by accelerator beam of high-energy protons with subsequent multiplication of neutrons in the cascade process of interactions of secondary intermediate-energy particles with target nuclei, subcritical core and blanket.On average, from 20 (for Hg and Pb targets) to 50 (for U target) neutrons are produced per 1-GeV proton in spallation reactions in the target containing nuclei of heavy elements (for example, Hg, Ta, W, U,).Heavy elements such as lead, bismuth, mercury, tantalum, and tungsten are considered as suitable materials for the targets. Lead-bismuth eutectic targets are successfully developed.It is demonstrated in the present paper that there exist optimal size of the target material allowing obtaining for the given incident particle energy maximum number of “spallation” neutrons. Results of calculations of energy spectrum of neutrons generated in the proton interactions with heavy targets for the energy range of incident protons from 0.8 to 1.4GeV.Implemented analysis of variation of neutron generation rate for cylindrical target with 10cm diameter and length from 1 to 120cm at impinging proton energies from 0.8 to 1.4GeV allowed calculating optimal target dimensions consisting of heavy nuclei for the nuclear power installations under design.Optimization of dimensions of neutron generating targets consisting of natural natBi, natHg, natPb и natW isotopes was implemented.

Measurement of gamma-ray production cross sections in Li and F induced by protons from 810 to 3700 keV

Differential cross sections for the reaction channels 7Li(p,nγ1-0)7Be (Eγ=429keV), 7Li(p,pγ1-0) (Eγ=478keV), 19F(p,pγ1-0)19F (Eγ=110keV), 19F(p,pγ2-0)19F (Eγ=197keV) have been measured in the proton energy range 810–3700keV, with an energy step of 10keV. The reactions channels 19F(p,pγ3-1)19F (Eγ=1236keV), 19F(p,pγ4-1)19F (Eγ=1349keV), 19F(p,pγ5-2)19F (Eγ=1357keV) have also been investigated in the proton energy range 1915–3225keV. The experimental set-up, the uncertainty budget, the comparison with other data and the progress assured by new data in the analytical use of standard-less Particle Induced Gamma-ray Emission (PIGE) are discussed.

The Mushroom: A half‐sky energetic ion and electron detector

AbstractWe present a time‐of‐flight mass spectrometer design for the measurement of ions in the ~30 keV to 10 MeV range for protons (up to ~40 MeV and ~150 MeV for He and heavy ions, respectively) and ~30 keV to 1 MeV range for electrons, covering half of the sky with 80 apertures. The instrument, known as the “Mushroom,” owing to its shape, solves the field of view problem for magnetospheric and heliospheric missions that employ three‐axis stabilized spacecraft, yet still require extended angular coverage; the Mushroom is also compatible with a spinning spacecraft. The most important new feature of the Mushroom is the method through which uncomplicated electrostatic optics and clean position sensing combine to permit many apertures to fit into a compact, low‐mass sensor head (or wedge), several of which (ideally eight) compose a full instrument. Most of the sensor head's volume is an empty, equipotential region, resulting in the modest 250 g mass of each 10‐aperture wedge. The Mushroom is capable of separating ion species across most of its energy range and angular field of view. For example, separation of the neighboring 3He and 4He isotopes is excellent; the full width at half maximum mass resolution has been measured to be 0.24 amu to 0.32 amu, respectively. Converting this to a Gaussian width σm in mass m, this represents a σm/m mass resolution better than 0.04. This separation is highly desirable for the flight program for which the first Mushroom was built, the Solar Probe Plus mission. More generally, we estimate the mass resolution to be σm/m ≈ 0.1, but this is energy, mass, and angularly dependent. We also discuss the solid‐state detector stack capability, which extends the energy range of protons and helium, with composition, to ~100 MeV.

Cross sections for nuclide production in proton- and deuteron-induced reactions on 93Nb measured using the inverse kinematics method

Isotopic production cross sections were measured for proton- and deuteron-induced reactions on 93 Nb by means of the inverse kinematics method at RIKEN Radioactive Isotope Beam Factory. The measured production cross sections of residual nuclei in the reaction 93 Nb + p at 113 MeV/u were compared with previous data measured by the conventional activation method in the proton energy range between 46 and 249 MeV. The present inverse kinematics data of four reaction products (90 Mo, 90 Nb, 88 Y, and 86 Y) were in good agreement with the data of activation measurement. Also, the model calculations with PHITS describing the intra-nuclear cascade and evaporation processes generally well reproduced the measured isotopic production cross sections.

Particle induced nuclear reaction calculations of Boron target nuclei

Boron is usable element in many areas such as health, industry and energy. Especially, Boron neutron capture therapy (BNCT) is one of the medical applications. Boron target is irradiated with low energy thermal neutrons and at the end of reactions alpha particles occur. After this process recoiling lithium-7 nuclei is composed. In this study, charge particle induced nuclear reactions calculations of Boron target nuclei were investigated in the incident proton and alpha energy range of 5–50 MeV. The excitation functions for 10 B target nuclei reactions have been calculated by using PCROSS Programming code. The semi-empirical calculations for (p,α) reactions have been done by using cross section formula with new coefficient obtained by Tel et al. The calculated results were compared with the experimental data from the literature.

Proton bombarded reactions of Calcium target nuclei

In this study, proton bombarded nuclear reactions calculations of Calcium target nuclei have been investigated in the incident proton energy range of 1–50 MeV. The excitation functions for 40 Ca target nuclei reactions have been calculated by using PCROSS nuclear reaction calculation code. Weisskopf-Ewing and the full exciton models were used for equilibrium and for pre-equilibrium calculations, respectively. The excitation functions for 40 Ca target nuclei reactions (p,α), (p,n), (p,p) have been calculated using the semi-empirical formula Tel et al. [5].

Experimental analysis of neutron and background gamma-ray energy spectra of 80-400 MeV 7Li(p,n) reactions under the quasi-monoenergetic neutron field at RCNP, Osaka University

To develop the 100-400 MeV quasi-monoenergetic neutron field, we measured neutron and unexpected gamma-ray energy spectra of the 7 Li(p,n) reaction with 80-389 MeV protons in the 100-m time-of-flight (TOF) tunnel at the Research Center for Nuclear Physics (RCNP) cyclotron facility. Neutron energy spectra with energies above 3 MeV were measured by the TOF method, which had been reported in our previous papers, and photon energy spectra with energies above 0.1 MeV were measured by the automatic unfolding function of the radiation dose monitor DARWIN. For neutron spectra, the contribution of peak intensity to the total intensity integrated with energies above 3 MeV varied between 0.38 and 0.48 in the proton energy range of 80–389 MeV. For gamma-ray spectra, highenergetic gamma-rays at around 70 MeV originated from the decay of π0 were observed with proton energies higher than 200 MeV. For the 246-MeV proton incident reaction, the contribution of gamma-ray dose to neutron dose is negligible because the ratio of gamma-ray dose to neutron dose is 0.014.

Gaas Displacement Damage Dosimeter Based on Diode Dark Currents

GaAs diode dark currents are correlated over a very large proton energy range as a function of displacement damage dose (DDD). The linearity of the dark current increase with DDD over a wide range of applied voltage bias deems this device an excellent candidate for a displacement damage dosimeter. Additional proton testing performed in situ enabled error estimate determination to within 10% for simulated space use.