High-energy threshold reaction rates on 0.8 GeV proton-irradiated thick Pb-target

Abstract
This works presents results of activation-aided determination of threshold reaction rates in 92 ²⁰⁹Bi, ^natPb, ¹⁹⁷Au, ¹⁸¹Ta, ¹⁶⁹Tm, ^natIn, ⁹³Nb, ⁶⁴Zn, ⁶⁵Cu, ⁶³Cu, ⁵⁹Co, ¹⁹F, and ¹²C samples and in 121 ²⁷Al samples. All the samples are aligned with the proton beam axis inside and outside the demountable 92-cm thick Pb target of 15-cm diameter assembled of 23 4-cm thick discs. The samples are placed on 12 target disks to reproduce the long axis distribution of protons and neutrons. In June 2006, the target was exposed for 18 hours to a 800-MeV proton beam extracted from the ITEP U-10 accelerator. The proton fluence and the proton beam shape were determined using the ²⁷Al(p,x)⁷Be monitor reaction. The total number of protons onto the target was (6.0±0.5)×10¹⁵. The reaction rates were determined by the direct gamma-spectrometry techniques. The GC-2518 detectors of 1.8 keV resolution and the DGDK-60V detectors of 2.9 keV resolution at the 1332 keV gamma-line were used to take the measurements. In total, 1196 gamma-spectra have been measured, and about 1500 reaction rates determined. The measured reaction rates were simulated by the MCNPX code using the following databases: ENDF/B6 for neutrons below 20 MeV, MENDL2 for 20-100 MeV neutrons, and MENDL2P for proton cross sections up to 200 MeV. An acceptable agreement of simulations with experimental data has been found.