TEMPERATURE RISE MEASUREMENTS FOR A SIMPLE MERCURY TARGET EXPOSED TO PROTON BEAMS

摘要

A specially designed and instrumented mercury target vessel was used to evaluate the energy distributionresulting from the interaction of a proton beam with a mercury target. The information obtained will beused to validate computer models being used to design the Spallation Neutron Source (SNS) target. Thetests were performed at the Los Alamos Neutron Science Center Weapons Neutron Research facility inLos Alamos, New Mexico, in August 2000. In the SNS, intense thermal shock loads are expected to causean enormous rate of temperature rise (～10~7 K/s), resulting in pressure waves in the mercury that may leadto large stresses on the thin walls of the mercury vessel. To guide the mercury target design and tobenchmark the computer design codes, the energy deposition was measured throughout the target. Threetypes of sensors were used to measure the temperatures: type K thermocouples, FISO Fabry-Perotsensors, and phosphor thermometry sensors. Part of the purpose of the experiments was to evaluate theFISO and thermographic phosphor sensors for use in a proton beam environment. Both sensors performedwell, although the FISO sensors proved to be somewhat fragile. The 800-MeV beam deposited protons atlevels of 2.84 H 10~(13), 1.48 H 10~(13), and 7.22 H 10~(12) protons per pulse. The vessel was 97.3 mm (3.83 in.)in diameter and 203 mm (8 in.) long. The peak temperature rise was approximately 10 K for the highestenergy deposition.