Low-density polyethylene (LDPE) is widely employed as an insulating material in applications where exposure to X-ray irradiation is possible. Under X-ray irradiation, space charge accumulation within LDPE can significantly distort the internal electric field and degrade insulation performance. In this paper, a high-resolution in-situ space charge measurement system compatible with X-ray irradiation was established based on the pulsed electro-acoustic (PEA) method. The space charge distribution characteristics of LDPE during polarization and depolarization processes under a DC electric field of 20 kV/mm with and without X-ray irradiation were comparatively investigated. The results indicate that X-ray irradiation induces substantial space charge accumulation near the irradiation surface, causing severe electric field distortion. During depolarization, charges trapped by irradiation-induced deep trap states persist within the material, maintaining elevated residual electric fields. These findings offer insights into the space charge behavior of LDPE under X-ray irradiation, providing a reference for insulation design in radiation environments.
 

LDPE; X-ray Irradiation; Space Charge; In-situ Testing; Pulse Electroacoustic Method