Cumulative $${\pi}$$-Mesons in $${}^{{12}}{C}{+}{}^{{9}}$$Be-Interactions at 3.2 GeV/Nucleon

In the FRAGM experiment at the heavy-ion accelerator$$-$$accumulator complex ITEP$$-$$TWA, yields of cumulative charged $$\pi$$ mesons have been measured in a fragmentation of carbon ions with the energy of 3.2 GeV/nucleon on a beryllium target. The momentum spectra of $$\pi$$ mesons cover four orders of the invariant cross section magnitude. They demonstrate the exponential fall with increasing energy. The measured inverse slope parameter is compared with similar measurements in nucleon–nucleus interactions and ion–ion collisions at lower energies. The energy dependence of the ratio of the yields of negative to positive $$\pi$$ mesons is presented. This dependence is discussed in a connection with Coulomb and isotopic effects. The obtained data are compared with predictions of several ion–ion interaction models.

Sterile neutrino oscillometry with Jinping

The existence of sterile neutrino is an open question in neutrino physics up to now. The method of neutrino oscillometry provides a powerful tool to test the common 3 + 1 sterile neutrino hypothesis, i.e. three active flavors and one sterile flavor. There are several antineutrino sources which can be used for this method. One of them is the well known isotope chain of $$^{144}\mathrm{Ce}$$144Ce–$$^{144}{\mathrm{Pr}}$$144Pr with initial activity around 50–100 kCi. It has compact size and might be installed either outside or inside the detector. Another one is the short-lived isotope $$^8{\mathrm{Li}}$$8Li, which can be produced in nuclear reaction of a proton beam hitting a beryllium target. The lithium source has only the out-of-detector option due to its large size. The proposed Jinping water-based liquid scintillator detector will be used as a detection volume. Above experimental setups will allow us to cover the current best fit values of oscillation parameters with 90% C.L. At the same time, it is sensitive to the region of the Neutrino-4 result.

ANALYSIS OF PARTICLE DISTRIBUTION IN A DOUBLE LAYER BEAM SHAPING ASSEMBLY RESULTED FROM 30 MEV-PROTON REACTIONS WITH BERYLLIUM TARGET USING THE PHITS PROGRAM

An analysis on the distribution of particle flux emanating from reactions of 30 MeV-proton with beryllium target in a double layer beam shaping assembly (BSA) has been carried out using the PHITS program. It studies important parameters relating to the distribution of proton, neutron, and gamma. It is revealed that reactions of proton and beryllium in double layer BSA produce fast neutrons and other protons, resulting from certain reactions, and recoil protons from the interactions of fast neutrons and hydrogen atoms. Fast neutrons are distributed around beryllium target, moderator, reflector, and collimator. They are moderated by Al and LiF material. Epithermal neutrons spread along the moderator, with a distribution that is tapering down as it approaches the end of the collimator (aperture). During its travel along the moderator, an epithermal neutron decreases in energy to become a thermal neutron. The spectrum of neutron beam produced by the double layer BSA is wide, which indicates that the neutron beam exiting the aperture consists of three kinds of neutrons, dominated by epithermal neutronswith energy range 1 eV – 10 keV.

Angular Distribution of Neutrons Around Thick Beryllium Target of Accelerator-Based 9Be(d, n) Neutron Source

An experimental work and simulations were carried out to determine the angular distributions of neutrons and yields of the 9Be(d, n) reaction over all angular range (360 deg) on a thick beryllium target as an accelerator-based neutron source at incident-deuteron energy 13.6 MeV. The neutron activation method was used in the experimental part using aluminum and iron foils as detectors to calculate the neutron flux. The Monte Carlo neutral-particles code (MCNP5) was used to demonstrate and simulate the neutron distribution, also to understand and compare with the experimental results. The neutron energy spectrum was computed using the projection angular-momentum coupled evaporation code PACE4 (LISE++) and the spectrum was adopted in MCNP5 code. Two experimental ways were used, one with beryllium target and another one without the beryllium target, to evaluate the neutron flux emitted only by the beryllium target. Typical computational results were presented and are compared with the previous experimental data to evaluate the computing model as well as the characteristics of emitted neutrons produced by the 9Be(d, n) reaction with a thick Be-target. Moreover, the results can be used to optimize the shielding and collimating system for neutron therapy.

Development of a regenerated Beryllium target and a thermal test facility for Compact Accelerator-based Neutron Sources

Recently, the possibility to use compact accelerators coupled to high current ion sources for the production of intense low energy proton or deuteron beams has motivated many research laboratories to develop accelerator based neutrons sources for several purposes, including Neutron Capture Therapy (NCT). The NCT needs a high flux, about 10 9 n.cm-2.s-1, of thermal neutrons (E<10 keV) at the tumour site. Up to now, the NCT required neutron flux was mainly delivered by nuclear reactors. However, the production of such neutron flux is now possible using proton or deuteron beams on specific targets able to stand a high pow er (~15- 30 kW) on a small area (~10 cm2). This specific target design, materials and supports, has to cope with extreme physical constraints . The LPSC team has conceived an original solution formed by a thin (8 μm) rotating beryllium target depos ited on a graphite wheel and coupled with a beryllium sputtering device for periodic 9Be layer restoration. By means of 9Be (d,n) 10B nuclear reaction, this target irradiated by a 10- -20 mA deuteron beam (1.45 MeV) should produce the required neutron flux. In order to validate the target design of the neutron flux production and the beryllium target thermal capabilities, we built a 30 cm diameter rotating Beryllium target prototype and a compact electron beam line able to deliver a power density of 3kW/cm2.

Directional reflection of cold neutrons using nanodiamond particles for compact neutron sources

Nanodiamond Particles (NDP) are new candidates for neutron reflection. They have a large scattering and low absorption cross-sections for low-energy neutrons. Very Cold Neutrons (VCN) are reflected from NDP with large scattering angles while Cold Neutrons (CN) have a quasi-specular reflection at small incident angles. A new scattering process has been added in Geant4 in order to examine the directional reflection of CN in an extraction beam made of NDP layer. Impurities in NDP are responsible for the up-scattered neutrons, especially hydrogen which has a large cross-section. Other impurities are also considered in Geant4 in order to produce a more accurate model for NDP scattering. The new scattering process is used to model a possible configuration of target-moderator-reflector in Compact Neutron Sources (CNS). A 13 MeV proton beam striking a beryllium target is chosen. Parahydrogen is placed as a cold moderator in order to produce CN. NDP are placed around the extraction beam for scattering the CN toward the exit of the beam. The results show that CN exiting the extraction beam can be increased thanks to the implemented NDP layer.

Design and Construction of an Imaging beamline at the Nagoya University Neutron Source

The Nagoya University Accelerator driven Neutron Source (NUANS) is constructed at the main campus of the Nagoya University. The electrostatic accelerator is used with the maximum proton energy and intensity of 2.8MeV, 15mA(42kW) respectively. Two neutron beamlines are designed at NUANS. The BL1 is dedicated to BNCT development. The BL2 is designed for research and development for neutron devices and neutron imaging. The neutrons used for the BL2 are generated by using the (p, n) reaction from a thin beryllium target. We constructed a compact target station for the BL2 and measured the neutron transmission image.