Abstract
The Japanese and American Study of Muon Interaction and Neutron detection (JASMIN) collaboration, has been conducting shielding experiments using the Fermilab anti-proton target station (Pbar) shielding assembly. A multi-foil technique was used to measure the high energy neutron spectra, in the range of 1 to 100 MeV, for the target station shielding configuration. The neutron spectra were de-convoluted using a new fitting method. This method is based on the assumption that a neutron spectrum can be expressed as a simple sum of two exponentials. The validity of the fitting method was confirmed by comparison with the results obtained using SAND-II computer code and theoretical calculations. Finally, it was found that there are simple correlations between reaction rates and the adjustable parameters in the fitting function.