在辐射育种和辐射保藏食品工作中，要求辐照量大和辐照量准

[1]

。目前国外在这方面辐照中使用的吸收剂量已由几千拉德到几兆拉德。大剂量的辐照，要求放射源强度大。要得到每分钟几千到几万伦的照射量率，若用

60

Co源，则须把多根

60

Co源（源强每根800克镭当量）组合起来才行，这就带来了放射源的排列问题。本文简要介绍在把单个钴源组合成板形放射源的场中，用面源理论来估计辐照场内的大照射量分布，测量与理论估算，理论值与实测值的比较。

The exposure in a radiation field with a large-scale extended radiation source and its theoretical estimation is shortly described in this paper. The theoretical values are in good agreement with the measurements. In case of a plate-type radiation source made up of putting numerous cobalt rods together

the distribution theory on field strength of extended radiation source may be used to evaluate the exposure distribution in the radiation field and

therefore

to obtain the places at which the dose in demanded. The relative error between the theorical and measured values is in general less than 9%.