Micro-collimator fabricated by alpha-particle irradiation of polyallyldiglycol carbonate polymer film and subsequent chemical etching

In the present paper, we propose a method to fabricate a “micro-collimator” with a thickness of 15 μm. A commercially available PADC film with a thickness of 100 μm was first chemically etched with NaOH/ethanol solution to obtain a thin PADC film. This thin PADC film was then irradiated by 5 MeV α particles through a “macro-collimator” with a thickness of 5 mm and a hole diameter of 1 mm. This PADC film with latent tracks was then further etched in aqueous NaOH solution to form the micro-collimator with a thickness of 15 μm and etched-through air channels were all confined to a circular area with 1 mm diameter. Verifications were performed by checking the etched α-particle tracks formed on a test PADC film from α particles having traveled through a 20 μm support substrate attached to the 15 μm micro-collimator (both substrate and micro-collimator also made of PADC). The results are discussed.