伽玛线辐射对PBN试样表面电荷累积的影响

Effects of Gamma-Ray Irradiation on Surface Charge Accumulation on Polybutylene Naphthalate

采用自制静电探头测量经60Co伽玛线辐射源辐射的聚萘二甲酸丁二醇酯(PBN)试样的表面电荷密度,分析辐射量对试样表面电荷特性的影响。实验结果表明,随着施加负直流电压时间的延长,试样表面电荷平均密度增大;随着辐射量的增加,表面电荷平均密度降低。认为伽玛线辐射引起的交联反应使表面态密度降低,是造成PBN带电能力下降的主要原因。

In this paper, polybutylene naphthalate （PBN） was employed as test sample to investigate the effects of gamma-ray irradiation on surface charge accumulation. The sample was previously irradiated in air up to 100 kGy and then up to 1000 kGy with dosage rate of 10 kGy/h by using a ^60Co gamma-source. The experiment was carried out on sample surface under a negative dc stress between two parallel electrodes. An electrostatic probe was designed to measure the surface charge density. Obtained results show that both max charge density and total charge decrease with increasing the total dose of irradiation. It indicates that the capacity of storing charges of the surface is reduced by the irradiation. The charge accumulation depends upon the density of localized surface states, which is varied by radiation induced cross-linking and degradation reactions.