Preliminary simulations of the neutron flux levels in the Fermilab tunnel and proposed SSC tunnel.

摘要

In the fall of 1985, a FNAL/LBL group measured neutron spectra in the Tevatron tunnel. During the machine cycle just ended, these experiments were refined and extended. Absolute magnitude and longitudinal distributions of the neutron flux were measured down the tunnel from a warm section in the beam pipe. A controlled N(sub 2) gas leak was introduced near the center of the warm section, so that by measuring rates as a function of gas pressure, beam-gas rates could be separated from background rates. To help support this experimental effort, detailed simulations of particle cascades in the Fermilab tunnel initialed by hadron-nucleus collisions in the center of the warm section were carried out using a version of HETC. The MORSE code was used to transport the low-energy neutrons. In this note, preliminary results from these simulations are presented, as well as results calculated at SSC energies, i.e., at 20 TeV. The simulations will become more detailed as the experimental analysis proceeds, and the feedback obtained from the experiment will allow further improvements in the transport capabilities. Final reports detailing both calculational and experimental results will be published.