Radiation Hardness Test of Eljen EJ-500 Optical Cement

Abstract

We present a comprehensive account of the proton radiation hardness of Eljen Technology's EJ-500 optical cement used in the construction of experiment detectors. The cement was embedded into five plastic scintillator tiles which were each exposed to one of five different levels of radiation by a 50 MeV proton beam produced at the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. A cosmic ray telescope setup was used to measure signal amplitudes before and after irradiation. Another post-radiation measurement was taken four months after the experiment to investigate whether the radiation damage to the cement recovers after a short amount of time. We verified that the radiation damage to the tiles increased with increasing dose but showed significant improvement after the four months time interval.

The STAR event plane detector

“…Especially in our case, using a groove with fixed width, epoxy was also crucial to keep the fibers from springing out of the groove. The particular epoxy used (Eljen EJ-500) was extensively tested and found sufficiently radiation-hard for conditions at RHIC [11].…”