Microdosimetric spctra were measured in order to gain the microdosimetric parameters of some epithermal neutron fields.Changes in dose mean lineal energy yd as a function of depth of heaby water showed a trend of softening with heaby water of the beam. The neutron absorbed dose was obtained by using the freqency mean lineal energy.Results show good agreement with measurements with the activation method using gold foil. This study demonstrated how microdosimetric parameters cahnge in radiation quality as a function of heaby water depth
