Development of 30 MeV electron LINAC for radioactive ion beam generation and N-TOF study

A 30 MeV RF electron linac-based neutron source will be developed by APPD; it will be commissioned in the Accelerator Complex at Bhabha Atomic Research Centre (V). This facility consists of radioactive ion beam generation and neutron time of flight (n-TOF) facility for various research applications. The n-TOF facility consists of electron gun that will generate 10 ns electron beam. It will be accelerated to 30 MeV by RF linear accelerator. The electron pulse at the exit of the linac will have 40% energy spread. A compression magnet is designed to compress 10 ns, 10 A electron pulse to 1 ns, 100 A. A 360°, 5-sector, zero gradient magnet having rectangular yoke of size 3.2 m X 2.7 m X 0.4 m and weight of ~24 Ton gives pulse compression ratio of 10:1 ata magnetic field of 0.1 1. In order to get the same compression ratio with reduced magnet size, a 720°, 9-sector magnet having zero magnetic field gradient is designed. A magnet will have five physical sectors through which an electron beam will rotate twice. The analytical solution and CST Particle Studio simulation results are presented. To get 10:1 compression ratio, ~0.15 T magnetic field will be required; the overall magnet size will be reduced to 2.1 mX 2.1mX 0.4 m. In order to understand the difficulties involved in the fabrication of magnet, a scale down model of the 5-sector magnet is fabricated and tested. This magnet produces 0.1 T magnetic field at 4200A-turns. (author)