Energy and target material dependence of the neutron yield induced by proton and deuteron bombardment

Abstract

The neutron yield for compact accelerator driven neutron sources depends on the target material, the ion type and its energy. When such sources are operated with low energy proton beams below 30 MeV, typical target materials are lithium and beryllium. New developments indicate that higher energies or a deuteron beam might be useful to increase the neutron yield at constant accelerator power. Here we present the total neutron yield analytically calculated for protons and deuterons at energies up to 100 MeV for various target materials. The total neutron yield depends on the involved cross sections and the stopping power of the target material. This study shows that for energies lower than 30 MeV light target materials with a deuteron beam are preferable whereas for energies above 30 MeV heavy target materials show a high neutron yield with little difference for a proton or deuteron beam.

The High Brilliance neutron Source (HBS): A project for a next generation neutron research facility

“…Table 1. Key parameters of the HBS Accelerator [5] protons of energy 70 MeV, up to 100 mA peak current, beam duty factor of 6%, average proton beam power of 420 kW High Energy Beam Transport (HEBT) [6] multiplexer (kicker & septum magnet) distributing the beam to three TMR stations Target [7] Ta target with microchannel water cooling; 10x10 cm 2 active area; designed for 100 kW power TMR stations [8] TMR 2 : 24 Hz (667 µs p-pulse)) TMR 1 & 3 : 96 Hz (167 µs p-pulse) each TMR offers 12 beam ports Moderators [9,10] thermal moderator: light water cold moderators: 1d «finger» moderators (solid mesitylene, solid methane, liquid para-hydrogen)…”

Sustainable neutrons for today and tomorrow—The Jülich High Brilliance neutron Source project

“…For the target design of HBS at a power level of 100 kW, tantalum as target material has been chosen [5]. The power density deposition with a target area of 100 cm 2 is 1 kW/cm 2 .…”

Optimization of moderator materials by NSGA II based on macroscopic cross-sections: applications in accelerator neutron sources

“…[8,9]. Currently, beryllium and lithium are used as the target materials of accelerator neutron sources [10,11]. For 7 Li (p, n) 7 Be and 9 Be (p, n) 9 B reactions, the neutron yield of 7 Li (p, n) 7 Be is about 2-10 times that of 9 Be (p, n) 9 B when the incident proton energy is less than 3.5 MeV.…”