New Neutron Time-of-Flight (NTOF) Facilities at the Brookhaven 200-MeV Linac

The installation of a new beam chopper and radio-frequency quadrupole (RFQ) preinjector (750 keV) at the Brookhaven National Laboratory (BNL) 200-MeV Linac will enable single micropulse selection (pulse width <1 ns) with periods ranging from 400 ns to 10 µs. The standard micropulse intensity is 1.2 ×109 p/µ pulse with dc-average beam currents of 50 nA-1 µA routinely available. The NTOF facilities consists of 30–100 meter flight paths at angles of 0, 12, 30, 45, 90, and 135°. Lower energies of 93, 117, 139, 161, and 181 MeV are also available as well as polarized beams at much reduced intensities. The present paper describes the new facilities, and the capabilities of future improvements and upgrades, for use in the BNL intermediate energy (p,n) experimental program.