Abstract
The ORNL electron LINAC, ORELA, began operation in 1969 and has been instrumental in providing improved neutron cross section data for many isotopes over the 0.002-60 MeV energy range. The ORELA utilizes a 4-30 ns <1000 Hz pulsed gridded electron gun, a 4 section RF LINAC, and a water-cooled and moderated tantalum target to generate short neutron pulses. The short pulse lengths and long flight paths provide high neutron energy resolution. Beam energy can range up to 180 MeV and a neutron production rate of up to 10e14 n/sec can be generated with 50 kW of beam power. Recent operation is at 8 ns, 525 Hz pulse rate and a target power of 5-10 kW. RF power for the accelerator sections are provided by four 24 MW 1300 MHz klystrons. Recent activities have included improvements to the accelerator vacuum, klystrons, interlocks and other upgrades. The current ORELA program is focused on cross-section measurements for the Nuclear Criticality Safety Program and for nuclear astrophysics. Detection and data analysis capabilities have been developed for making highly accurate measurements of neutron capture, neutron total, (n,alpha), and (n,fission) cross sections simultaneously on different beam lines.
