Determination of absorbed dose within an A150 plastic phantom for a d(13.5 MeV) + Be neutron source

In the collimated beam of a d(13.35 MeV) + Be neutron source the total absorbed dose within an A150 plastic phantom was determined using three independent methods: the twin-detector method, measurements with a tissue-equivalent calorimeter and a Monte Carlo calculation of the spectral neutron fluence within the phantom. The front of the cubic phantom was positioned at a distance of 800 mm from the neutron source. the absorbed dose data obtained by the three methods at phantom depths of 27 and 52 mm are consistent within their uncertainties. Between phantom depths of 10 and 60 mm a mean dose gradient of (1.61 +/- 0.02) Gy C-1 mm-1 has been derived.