Research on MCNP4C2 Code for calculation of gamma dose distribution for Dalat Co-60 Unit

The paper presents the results of Institutional R and D project ''Research on MCNP4C2 Code for calculation of gamma dose distribution for Dalat Co-60 Unit '' performed by Dalat Nuclear Research Institute (DNRI). In the field of irradiation, it has been special importance for an estimation of dose distribution since every point in chamber needs to be determined so as to apply for appropriate dose-level irradiation of particular objects. It is meaningful in case of irradiating for small-size samples. Several of methods used to determine dose distribution, among those the ways being carried out mainly are using TLD or Fricke dosimeter so far. These dosimeters were positioned at points of interest, from that referring gamma dose rate at certain position through some of calibrated and measured steps. The other effective-approved approach is doing by MCNP Code in replaceable for the above-mentioned classical ways. Results from MCNP calculation in comparison with Fricke experimental results (error about 11%) affirm the feasibility of using modern-calculated programme in dose distribution calculation for any irradiated unit. (author)