Deuteron Beam Research Articles

Long Range Optical Distance Sensors for Liquid Metal Free Surface Detection

For the demonstration of fusion power plant technology, DEMO dedicated materials are necessary to cope with the harsh environment of high energy neutrons. For this purpose, the international neutron irradiation facility for fusion materials IFMIF/DEMO Oriented Neutron Source (DONES) is planned to be built in Granda, Spain. In the DONES facility, a deuteron beam hitting the lithium target produces a high energy neutron flux. Due to the high-power density, the windowless target is a free surface liquid lithium flow in a duct with a concave backplate. In order to keep the heat released by the beam within the liquid lithium and to avoid its intrusion in the backplate, a stable configuration of the free surface flow with a setpoint layer thickness of 25 ± 1 mm is crucial. In particular, stable wave structures, so called wakes, which occur from accumulated impurities at the nozzle edge, can cause a critical local decrease in the layer thickness of more than 1 mm. Therefore, it is necessary to better understand the nature of these wakes and to be able to monitor the surface profile to shut down the beam in case of a critical thickness loss, but to avoid unintended shutdowns. In the context of this work, currently available optical sensors were tested on their capability of detecting a specular liquid metal surface at measurement distances of several meters. After an initial selection, two optical sensors were further considered. Experiments with the liquid metal alloy GaInSn and simulations with the software Blender of the selected optical sensors for their capability of measuring distances of liquid metal were conducted. The results showed a significant dependency of the measurement results on the waviness of the liquid metal surface. Nevertheless, it was possible to resolve the wavy liquid metal surface with a sufficient resolution to detect critical wake structures.

Study of the Elastic Scattering in the d + 11B system for EBS purposes

The implementation of boron in several fields, such as in the creation of p-type semiconductors in electronics, has created the need for the accurate quantitative determination of its depth profile concentrations in near surface layers of various matrices. In the framework of IBA techniques a combination of Elastic Backscattering Spectroscopy, along with Nuclear Reaction Analysis, has been proposed in order to address the current needs for boron depth profiling, focusing on the use of proton beams. Deuteron beams however offer superior mass resolution with similar stopping power values and simultaneous excitation of most light elements. Unfortunately, the lack of experimental datasets concerning the deuteron elastic scattering on boron impedes their use. Thus, in the present work, the first set of measurements for the 11B(d,d0) differential cross section covering the Ed,lab=1300-1860 keV energy range for the backscattering angles of 150ο, 160ο and 170ο were carried out. The study was conducted at the 5.5 MV Tandem Accelerator of the Institute of Nuclear and Particle Physics, in the National Center of Scientific Research “Demokritos”, Athens, Greece. The target was a thin, self-supporting aluminum foil, upon which a thin natB (isotopic ratio: 11B 80.1%, 10B 19.9%) layer was deposited using the sputtering technique at RBI, Zagreb, Croatia, followed by the evaporation of an ultra-thin layer of 197Au on top for normalization and wear protection purposes. The outgoing particles were detected using silicon surface barrier (S.S.B.) detectors and the differential cross sections for elastic scattering were determined from the resulting spectra via the relative technique

MiniSPD Stand for Testing Si-Detectors

SPD (Spin Physics Detector) collaboration proposes to install a universal setup in the second interaction point of the NICA collider under construction (JINR, Dubna) to study the spin structure of the proton and deuteron. It plans to carry out research of spin-related phenomena with polarized proton and deuteron beams at a collision energy up to 27 GeV and a luminosity up to 1032 cm−2 s−1. MiniSPD stand is manufactured as a setup for testing SPD detector prototypes with cosmic muons at LHEP. It allows to carry out checkout of the Data Acquisition System (DAQ), the Detector Control System (DCS). Young physicists and students working at this test bench gain experience of work with real detectors of the future SPD setup. In this report, we give some information about the basic tasks of SPD projects. The results of simulation and comparison with data on cosmic rays at this stand for three modules of silicon plates are also presented.

The 40Ar(d,p)41Ar cross section between 3–7 MeV

To determine the safety of using argon as a deuteron beam stopping material, the 40Ar(d,p)41Ar cross section was measured at average deuteron energies of 3.6 MeV, 5.5 MeV, and 7.0 MeV using an activation method. A 16-MeV deuteron beam produced by Lawrence Berkeley National Laboratory’s 88-Inch Cyclotron was degraded to each energy by nickel foils and the front wall of an aluminum gas chamber. The reduced-energy deuterons were used to activate a sample of natAr gas. After each irradiation, the gas chamber’s 41Ar activation was measured with a high-purity germanium detector. The cross sections measured were larger than a previous measurement by ∼40%.

Ion beam stopping power effects on nuclear fusion reactions

Fusion reactions in a plasma environment are fundamental issues with general interest in high energy density sciences. The reaction rate in an astro-system, which may differ from cold matter, is an important subject in the ambiguous problems of elemental abundance. In addition, the stopping of charged particle in plasma has a considerable impact on the design of nuclear fusion reactors as it is related to the α-particle heating process and ion-driven fast ignition, but still needs better understanding. In this research, an experiment on laser-driven D–D fusion reactions (D + D → 3He + n) has been carried out to investigate the effects of ion stopping power in plasma on fusion reactivities. The neutron yields, plasma density, and deuteron energy loss in the plasma have been measured simultaneously, and the plasma temperature has been analyzed from simulations. It is experimentally demonstrated that the fusion reaction yield is closely correlated with ion beam transportation in the plasma. As a cold target heated to plasma, the reaction probabilities from a deuteron beam and deuterated target interactions can be enhanced or suppressed, which is ascribed to the deuteron stopping power variation in the plasma. The results show the importance of considering the temperature adjusted ion stopping power to correctly model the fusion reaction yields. This work has an impact on understanding the fusion reactions in plasma environment, which is also likely to help achieve higher neutron yields.

Cascade Models in Simulation of Extended Heavy Targets Irradiated by Accelerated Proton and Deuteron Beams

The paper presents a survey of the main numerical models used for simulation of interaction of accelerated particle beams with target nuclei. These models form the core of the software for simulation of various experiments and experimental facilities both for scientific and applied purposes. The beam and target parameters considered in detail in this study (protons and deuterons with energies from 0.66 to 4 AGeV and bulk U targets) cover the range of interest in development of new concepts of nuclear power production aided by accelerated particle beams.

Nuclear data libraries for IFMIF-DONES neutronic calculations

International Fusion Materials Irradiation Facility-DEMO Oriented NEutron Source (IFMIF-DONES) is an installation aimed to irradiate with a high neutron flux materials relevant for the construction of the DEMOnstration fusion power plant (DEMO), in order to study the damage due to irradiation. Neutrons are generated using a 40 MeV and 125 mA deuteron beam impinging on a thick liquid lithium target. With these characteristics, damage due to irradiation comparable to that in the first wall of a fusion power reactor is achieved. In this paper we investigate the differences in the neutronic calculations of the IFMIF-DONES design when using different nuclear data libraries. We first studied the differences in neutron production due to Li(d, xn) reactions between different models and evaluations, comparing the different results with experimental data. Additionally, we tested the performance of the MCNP6.2 and Geant4 Monte Carlo codes when using deuteron incident data libraries. Then, we performed neutronic calculations of the IFMIF-DONES design using the most reliable Li(d, xn) neutron production models available, which are the FZK-2005 and JENDL/DEU-2020 evaluations according to the results obtained in the first part of the study. Thus, the differences in these evaluations are propagated to different neutronic calculation results: neutron flux, primary displacement damage, gas production, and heating in the materials to be irradiated. Finally, we also carried out these same neutronic calculations while using different nuclear data libraries for the neutron transport.

High-repetition-rate, multi-MeV deuteron acceleration from converging heavy water microjets at laser intensities of 1021 W/cm2

We demonstrate high repetition-rate deuteron acceleration by irradiating a continuously flowing, ambient temperature liquid heavy water jet with the high-intensity ALEPH laser. The laser delivered up to 5.5 J (120 TW, 1.2 × 1021 W/cm2) laser energy on target at 0.5 Hz. A high repetition-rate Thomson parabola spectrometer measured the deuteron beam energy spectra on each shot for 60 sequential shots (two minutes). Peak fluxes of 5×1010 deuterons/sr/pulse, corresponding to an average flux of 1.5×1012 deuterons/sr/min, were demonstrated with deuteron energies reaching up to 4.4 MeV. High shot-to-shot stability is observed up to 40%–50% of the maximum deuteron energy. These deuteron beams are suited for fast neutron production through deuteron breakup in a converter yielding energies similar to deuteron–deuteron (D–D, 2.45 MeV) fusion reactions of importance for material damage studies.

Upgrade of the 4-rod radio frequency quadrupole for SARAF Phase II Linac

The 176 MHz 4-rod radiofrequency quadrupole (RFQ) is the crucial part of the Soreq Applied Research Accelerator Facility (SARAF) injector and must be able to operate at RF powers up to 190 kW continuous wave and transport 5 mA proton and deuteron beams. The SARAF Phase I RFQ is planned for use in Phase II. The period between the termination of Phase I and the installation of Phase II provided an opportunity to introduce RFQ improvements to fully meet the Phase II requirements. These upgrades and improvements are presented in this report together with the results of the recent conditioning campaigns.

Neutral-current electroweak physics and SMEFT studies at the EIC

We study the potential for precision electroweak (EW) measurements and beyond-the-Standard Model (BSM) searches using cross-section asymmetries in neutral-current deep inelastic scattering at the electron-ion collider (EIC). Our analysis uses a complete and realistic accounting of systematic errors from both theory and experiment and considers the potential of both proton and deuteron beams for a wide range of energies and luminosities. We also consider what can be learned from a possible future positron beam and a potential tenfold luminosity upgrade of the EIC beyond its initial decade of running. We use the SM effective field theory (SMEFT) framework to parametrize BSM effects and focus on semileptonic four-fermion operators, whereas for our precision EW study, we determine how well the EIC can measure the weak mixing angle. New features of our study include the use of an up-to-date detector design of the EIC Comprehensive Chromodynamics Experiment and accurate running conditions of the EIC, the simultaneous fitting of beam polarization uncertainties and Wilson coefficients to improve the sensitivity to SMEFT operators, and the inclusion of the weak mixing angle running in our fit template. We find that the EIC can probe BSM operators at scales competitive with and in many cases exceeding LHC Drell-Yan bounds while simultaneously not suffering from degeneracies between Wilson coefficients.

The NICA-SPD project: a new tool to investigate the hadron structure

SPD is an international Collaboration gathering around the Spin Physics Detector at the Nuclotron-based Ion Collider FAcility (NICA), presently under construction at the Joint Institute per Nuclear Research, in Dubna. The project is briefly presented with special focus to the opportunities opened by the collision of high luminosity polarized proton and deuteron beams with total energy up to $\sqrt{s}$=27 GeV. Examples of the foreseen research program are highlighted, in connection with the spin structure of light nuclei, the proton gluon content and the spin dependence of the nucleon-nucleon interaction. The unicity of NICA-SPD makes the future results complementary to the studies that have been or will be performed at other polarized hadron machines in different energy domains.

Thermonuclearizing the plasma focus—converting plasma focus fusion mechanism from beam-gas target to thermonuclear

It has been reported that over a range of 3–280 kJ, neutron-optimized deuterium plasma focus machines operate with a near constant speed factor S = 89 ± 8 kA cm−1 per (torr)0.5. This near-constant value of S is consistent with a narrow range of peak axial speeds approximately 10 cm μs−1 and peak radial speeds 20–30 cm μs−1, resulting in focus pinch temperatures less than 0.5 keV and inductively generated high voltages, producing deuteron beams with energies from high tens to hundreds keV. The low pinch temperatures and high beam-deuteron energies result in fusion neutrons predominantly from a beam-target mechanism. A converging taper ending in radius a e, is added to the end of the standard cylindrical anode of radius ‘a’. This taper converts the pinch from one with starting radius ‘a’ to one with a reduced starting radius a e. This increases the value of S and consequently the pinch temperature. This study examines the scaling of the end taper and finds that a taper ending in a radius, which is 1/20 that of the before-taper section increases the pinch temperature by a factor approximately 200, to above 20 keV. This increases the thermonuclear cross-sections by up to 14 orders of magnitude. Numerical experiments using the Lee code confirm that the thermonuclear component of the fusion yield becomes predominant. Such a taper may be considered as a thermonuclear converter.

Fission reactions of natural uranium in a deuteron beam by activation detectors

Herein, an investigation of a deeply subcritical uranium assembly irradiated by a high-energy deuteron beam is presented. The determination of the total number of fission events is a key task in these investigations. Thus, this study is focused on the investigation of the number of fission events induced by deuterons, neutrons, and protons inside the deuteron beam volume. To measure the number of fission products in uranium activation detectors, germanium gamma detectors have been used. Furthermore, the total number of fission events has been measured by applying Solid State Nuclear Track Detectors (SSNTDs). The new method for determining the number of fissions using activation detectors is compared with the SSNTD and Monte Carlo (MC) methods. The method estimates the total number of fission events and agrees with the results obtained using the SSNTD and MC methods. The experiments were conducted at JINR, Dubna, Russia.

DONES Systems identification and requirements allocation

• Systems identification of IFMIF-DONES for work distribution and responsbility allocation. • System-of-Systems to Group-of-Systems type mapping. • Alignment of Systems identification and requirement allocation. The mission of the DONES program is to develop a database of fusion-like neutron irradiation effects in the materials required for the construction of the Demonstration Fusion Power Reactor (DEMO) for benchmarking of radiation response of materials. In order to do this, the DONES facility will be built to provide a neutron source producing high-energy neutrons at sufficient intensity and irradiation volume. DONES will generate a neutron flux with a broad energy distribution covering the typical neutron spectrum of a (d-t) fusion reactor. This is achieved by utilizing Li(d,xn) nuclear reactions taking place in a liquid Li target when bombarded by a deuteron beam. The energy of the deuterons (40 MeV) and the current of the accelerator (125 mA) have been tuned to maximize the neutron flux to get irradiation conditions comparable to those in the first wall of a fusion power reactor. For the success of this mission, the needs of all the stakeholders shall be very clearly stated, considering the whole lifecycle of the facility. Once the needs are clear, they shall be translated into specific requirements, following a top-down approach, to be allocated to the different systems or groups-of-systems (GoS). To do this, it is essential to properly identify which parts shall be treated as a System or GoS, as they shall be designed accordingly, and the requirements allocated in consequence.

Effect of Nuclear Interaction on the Reactivity and the Power Deposited by Injected Deuteron Beam in the 3He–6Li Plasma

Effect of Nuclear Interaction on the Reactivity and the Power Deposited by Injected Deuteron Beam in the 3He–6Li Plasma

Design of PLC and EPICS based control system for a deuteron RFQ

Peking University and Southwestern Institute of Physics are jointly developing a new deuteron RFQ to study the migration and deposition of impurities on the first wall of a tokamak facility. This RFQ will accelerate a 10-mA deuteron beam from 40 keV up to 1.5 MeV at a duty factor of 1%. In this paper, the detailed design of the prototype control system based on a Siemens PLC and EPICS/CSS software environment for the RFQ accelerator is presented. The system is composed by many kinds of sub-systems developed using different hardware solutions. The interlock protection mechanism is introduced into the control system. The EPICS Archiver Appliance is used to provide the service of data archiving and retrieval. The system has been successfully implemented for RF conditioning and beam commissioning.

Electrochemical co-deposition of Ni–Gd2O3 for composite thin targets preparation: Production of 155Tb as a case study

In the last years, 155Tb has attracted enormous interest due to its potential role in theranostics in nuclear medicine. To estimate its production yield, the aim of this study was to develop a method to prepare thin Gd-enriched-containing targets aimed at the 155Gd(d, 2n)155Tb nuclear cross section measurement. To this end, the electrochemical co-deposition method has been chosen to manufacture Ni–Gd2O3 composite targets. Several process parameters that have an impact on the deposit quality, have been investigated to increase the incorporation of Gd mass (up to 3 mg). To validate the concept, seven targets made by natural Gd were irradiated with deuteron beams at the GIP ARRONAX facility cyclotron, with an energy range ranging from 8 MeV to 30 MeV to extract the cross section values by using the stacked-foils method. Results obtained turned out to have great consistency with existing published data thus validating the proposed method. Therefore, an alternative target manufacturing concept aimed at cross section measurement is presented in this work.

Probing yields and angular distributions of Be(d,n) neutrons with novel target of compressed beryllium-powder

A comprehensive study was conducted in the Cyclotron laboratory at National Research Tomsk Polytechnic University on the use of a new type of target utilized in the production of fast-neutrons. The flux and spectra of the fast-neutrons emitted by a novel target of compressed beryllium powder were studied. The neutron angular distribution was measured using Fe and Al foils as detectors in different angular situations of the target relative to the incident deuteron beam. It was found that there are some discrepancies in the neutron flux at 0° degree for the detectors, up to about 20% for different target-beam angle. Likewise, the flux of neutrons in the energy range between 1 and 6 MeV make up about 83% of the total flux. Compering with previous works using solid target, we found an increase of nearly twice the yield of fast neutrons. And there is a probability that increase would rise steadily as the deuteron energies exceed 12 MeV as was the case in our work. The results of this study are new and promising and we can obtain a relatively greater neutron yield when using a compressed powder target. This is reflected positively on many applications that use fast-neutron beams, such as radiotherapy, radioactive isotopes, and even nuclear fusion experiments, among others.

Development of a Radio-Frequency Quadrupole Accelerator for the HL-2A/2M Tokamak Diagnostic System

In order to figure out the migration and deposition of impurities on the first wall of HL-2A/2M tokamak, Peking University and Southwestern Institute of Physics are co-developing a deuteron RFQ as part of the in situ ion-beam diagnostic for the material. The RFQ, which operates at 162.5 MHz, is designed to accelerate a 10-mA deuteron beam from 40 keV up to 1.5 MeV. Key design considerations and the final design parameters are presented. The RFQ has been conditioned at a 1% duty factor for 80 h at RF cavity power of 55 kW. The specific shunt impedance of the cavity is 221 kΩ·m by measuring the bremsstrahlung spectrum. The intrinsic Q-value after the high-power tests measured by the Ring-Down method is 13,780. Beam commissioning has been taken place during the first half of 2021, and the beam measurements include beam current and energy of 2H+ ion. A 10 mA 2H+ beam was successfully accelerated through the RFQ.

Development of ECR ion source with high-temperature superconducting REBCO coils

A new High-Temperature Superconducting ECR (HTS-ECR) ion source is under development in Research Center for Nuclear Physics (RCNP), Osaka University. This ion source will be used for production of high intensity proton, deuteron and He ion beams. The HTS-ECR magnets are composed of three solenoid coils and a set of sextupole coils made of REBCO tapes, a high-temperature superconductor. The HTS-ECR ion source is designed to operate at frequency of 2.45 GHz and 10 GHz. Performance test of the HTS coils had been carried out at 31 K and 77 K. This HTS coil technology will be applied to development of a meter-size HTS coil system of a high intensity compact AVF cyclotron. This paper introduces the basic design of the HTS-ECR ion source. The performance test results showed that REBCO solenoids remain superconducting state with a current up to 400 A. Simulation results of the magnetic field and electromagnetic field distributions in a plasma chamber fulfilled the requirements of electron cyclotron resonance conditions at 2.45 GHz and 10 GHz. Simulation result of mirror ratios and electromagnetic field amplitudes are also presented in this paper.