UCN Source at an External Beam of Thermal Neutrons

Figure 7

Spectrum of neutrons escaping from the methane cavity through the exit window. Thin line indicates the results of measurements. Points correspond to the numerical simulation of our experiment. Dashed line illustrates the Maxwellian distribution, which provides the largest count rate of neutrons with the wavelength of 8.9 Å. Blue line shows a Maxwellian distribution fitting the data in the best way. The integrals under all curves are equal to each other.