[en] A ''rabbit'' system has been installed in an insert at the Los Alamos Spallation Radiation Effects Facility (LASREF). Spallation neutrons at LASREF are produced by the passage of the LAMPF 800-MeV proton beam through the Isotope Production (IP) targets and into the beam stop. This dosimetry insert allows measurement of the spallation neutron and secondary proton fluxes and energy spectra in any of the 12 neutron irradiation locations. Four ''rabbit'' tubes allow radial measurements at 0.12, 0.18, 0.27, and 0.38 meters off beam centerline. Aluminum capsules (''rabbits'') are used to hold the activation foils. As many as five capsules can be stacked on top of one another in each tube to allow measurements below, on, and above beam centerline. Thirteen multiple-foil activation experiments were done at these two locations. Neutron spectra were similar with the exception of the reduction of the high-energy tail outside the beam stop. The spectra outside the beam stop for eight and zero IP targets were similar in spectral shape but reduced in magnitude by a factor of two when eight IP targets were inserted into the proton beam. Measurements showed no difference in the flux below, on, or above beam centerline. With respect to the radial variation in the flux, measurements showed similar spectral shapes between the first three tubes. The fourth tube showed an enhancement in the 24-keV region due to the transmission window in the iron cross section. The ''rabbit'' system is available for use by experimenters at LASREF

[en] Operation of a new irradiation facility at the beam stop (Target Station A-6) at the Clinton P. Anderson Los Alamos Meson Physics Facility(LAMPF)began in May 1985. The facility is now fully operational. A closed-loop water system, a closed-loop helium system, remote handling procedure for activated materials, experiment change-out procedures, and experiment control equipment are all in place. Experience dictated a change in irradiation capsules from a system that used metal seals to a system that is completely welded. The seals were found to be unreliable and difficult to replace by remote means. Several materials have been irradiated in the direct 760-MeV proton beam. Material property changes as well as a helium production in a variety of materials are being investigated. A special sample holder that ca accommodate transmission electron microscopy(TEM)specimens, isolate them from the cooling medium, maintain fixed temperature, and retain essentially a stress-free state has been developed. Remote handling retrieval of these specimens is being developed. Activation foil measurements are being made to determine the secondary particle flux and spectrum (charged particles and neutrons) that result from interaction of the direct proton beam with targets at the beam stop