THE EFFECT OF DEPOSITION RATE AND SAMPLE THICKNESS ON THE LUMINESCENCE EMITTED BY ELECTRON IRRADIATED POLYCRYSTALLINE H_2O ICE

摘要

The luminescence arising from the excitation by 0.53 MeV electrons of vacuum deposited polycrystalline ice at 77 K, has been studied as a function of deposition rate and ice thickness. Changes in deposition rate from 0.03 to 17 mm h~(-1), at various constant sample thicknesses, affected the luminescence intensity, I, but did not significantly affect the decay half-life, nor C in the equation I = A + B( 1 - C~n) for the dependence of light intensity, I, on the number of electron pulses, n. Increases in ice thickness from 0.25 μm to 5 mm caused: (ⅰ) an increase in luminescence intensity to a plateau value at a thickness around 2 mm; (ⅱ) a blue-shift in the spectral maximum from 405 to 385 nm; and (ⅲ) an increase in the decay half-life from 90 to 160 ns.