LEDA is the front-end demonstration of the APT machine, with the eventual goal of 100 mAmp proton beam at 12 MeV. Currently the RFQ section of the machine (6.7 MeV) is being exercised. LEDA is now operating in both pulsed and cw mode, with the current climbing each day. Pulsed mode has reached 89 mAmp, and will be pushed to 100 mAmps soon. CW mode has reached 67mAmps.
In the APT Materials ED&D activities, the first revision of the APT Materials Handbook was issued in June. This is the first materials handbook ever written for high energy particle accelerators, and represents the work of a large international collaboration over the past 5 years. Our last irradiation at the 1 mAmp LANSCE beamstop was completed in December, and in addition to the mechanical test samples, also included specific experiments involving measurements of on-line corrosion rates, decay heat, cooling water and Helium gas contamination from spallation products. Major work on sample analysis is being performed at the LANL CRM facility hot cells, ORNL and PNNL.
The APT-sponsored MCNPX code version 2.1.5 was released on May 21st, and is now being beta-tested at 73 institutions worldwide. MCNPX is the extension of MCNP to all particles and all energies, and includes all standard LAHET and CEM physics modules. In addition, 41 evaluated libraries of neutron reactions up to 150 MeV, proton reactions from 1 to 150 MeV, plus a number of photonuclear libraries have been generated for use in the code. The proton and neutron work have been released to ENDF. A tutorial on MCNPX will be held at the American Nuclear Society meeting in Long Beach, Ca, on November 13, 1999.
Benchmark measurements of decay heat and energy deposition have also been completed, as well as a new set of proton reaction cross section measurements performed at the BNL AGS.
Energy deposition measurements in a water phantom at the WNR neutron beam (to ~600 MeV) facility were done in November. This is a benchmark for simulations now underway at Georgia Tech to generate high energy fluence-to-dose calculations for use by the APT project with MCNPX, for neutrons and protons. A preliminary set of factors has already been released which combines existing high energy calculations from a number of sources. After due review, a set of factors will be presented to the ANS standards committee to extend existing values.