The influence of target film material and coating on neutron yield and sputtering yield

The long-life, high yield deuterium-deuterium (D-D) neutron tube has become one of the research hotspots. Here, deuterated polyethylene target, heavy water target and titanium target were investigated by Stopping and Range of Ions in Matter (SRIM). The calculation showed that the deuterated polyethylene target, which was a potential target material, had the highest yield at an incident energy of 120 keV. Further, considering the unfavorable factors such as impurity ions and high temperature, the coating was used to protect the target material. Diamond, boron carbide, boron nitride, silicon carbide, and aluminum carbide were selected. The simulation results showed that the diamond composite deuterated polyethylene film had the best sputtering resistance, and the aluminum nitride composite heavy water target film had the lowest sputtering yield. The two coating materials shield the target, reduced the energy loss of incident ions, and provided a new method for the research of high yield and long life neutron tube.

Deuterated polyethylene nanowire arrays for high-energy density physics

The interaction of intense, ultrashort laser pulses with ordered nanostructure arrays offers a path to the efficient creation of ultra-high-energy density (UHED) matter and the generation of high-energy particles with compact lasers. Irradiation of deuterated nanowires arrays results in a near-solid density environment with extremely high temperatures and large electromagnetic fields in which deuterons are accelerated to multi-megaelectronvolt energies, resulting in deuterium–deuterium (D–D) fusion. Here we focus on the method of fabrication and the characteristics of ordered arrays of deuterated polyethylene nanowires. The irradiation of these array targets with femtosecond pulses of relativistic intensity and joule-level energy creates a micro-scale fusion environment that produced $2\times {10}^6$ neutrons per joule, an increase of about 500 times with respect to flat solid CD2 targets irradiated with the same laser pulses. Irradiation with 8 J laser pulses was measured to generate up to 1.2 × 107 D–D fusion neutrons per shot.

The production of deuterated polyethylene targets

In this contribution, we describe the method used to produce deuterated polyethylene (C2D4) targets. The modification of method based on polyethylene dissolution in hot xylene resulted with stable thin C2D4 targets.

Simulations of the measurement results of differential cross sections of n-p and n-d elastic scattering at CSNS Back-n WNS

Differential cross-section data for the n-p and n-d elastic scattering (1H(n, el), 2H(n, el)) are collected and analyzed from EXFOR library. For En > 20 MeV, the experimental results for both reactions are scarce with large uncertainties and discrepancies in general. For En ≤ 20 MeV, the experimental results lack systematicness, most of which were measured around En = 14 MeV even though the differential cross sections of n-p scattering in 1 keV ≤ En ≤ 20 MeV region are recommended as standard. Taking these facts into account, more accurate and systematic measurements are planned. The experiments will be conducted using ΔE-E detectors of the Light-charged Particle Detector Array (LPDA) system at China Spallation Neutron Source (CSNS) Back-n White Neutron Source (WNS), and simulations are carried out. Using polyethylene and deuterated polyethylene as samples, both n-p and n-d scattering reactions are simulated along with the neutron-induced 12C background reactions, and the 2-D spectra and the counting rates of the ΔE-E detectors are obtained. According to the simulations, the applicable neutron energy range and positions of the detectors are recommended, and the beam time for the event and background measurements is suggested.

DNP with Trityl Radicals in Deuterated Polyethylene

Chemically doping with trityl radicals was performed in fully deuterated polyethylene. The behavior of paramagnetic centers has been investigated by ESR X-band spectrometer. The highest deuteron polarization was 8% at 2.5 T and 1 K with a spin concentration of [Formula: see text] spins/g.