Scintillation and luminescence in transparent colorless single and polycrystalline bulk ceramic ZnS

Abstract

ZnS:Ag is a well-known, extremely bright scintillator used in powder form for α-particle detection and, mixed with powdered LiF, for thermal neutron detection. Recently, we discovered some colorless and transparent commercial bulk single-crystal and polycrystalline (chemical vapor-deposited) ZnS forms that scintillate in response to α-particles. The scintillation light transmits through the sample thickness (millimeters), challenging the commonly held assumption that ZnS is opaque to its own scintillation light. Individual α-particle events were imaged in space and time using a charged-particle camera originally developed for medical imaging applications. Photoluminescence (PL) and PL excitation show that scintillating bulk ZnS likely depends on different electronic defects than commercial ZnS powder scintillators. These defects, associated with copper and oxygen, are discussed in relation to PL results and extensive literature assessment. Commercial transparent ZnS is routinely produced by chemical vapor deposition to sizes larger than square meters, enabling potentially novel radiation detection applications requiring large, thick apertures.

Study of the thermal neutron detector ZnS(Ag)/LiF response using digital pulse processing

“…In several applications the importance of pulse shape discrimination (PSD) capability of the ZnS(Ag) scintillator is evidenced in situations where it is necessary to discriminate neutron events from the gamma ones. The wavelength of maximum probability of emission is around 425 nm [2], and the observed decay times are between 3 and 5 ns (for electrons and γ's) and between 100 ns and 250 ns (for α's).…”

“…The silver-activated zinc sulfide, ZnS(Ag), scintillator has been used as detector for charged particles since radioactivity was discovered and used as screen in 1903 by Sir William Crookes [1]. This scintillator is known to have a very high scintillation efficiency compared to NaI(Tl) (95000 photons/MeV) [2]. Layers of ZnS(Ag) powder have a significant self-absorption and scattering of light, which lead to a significant decrease of the light output for thicknesses above ∼ 100 µm [2].…”

“…This scintillator is known to have a very high scintillation efficiency compared to NaI(Tl) (95000 photons/MeV) [2]. Layers of ZnS(Ag) powder have a significant self-absorption and scattering of light, which lead to a significant decrease of the light output for thicknesses above ∼ 100 µm [2]. The scintillation yield of the ZnS(Ag) for high-energy electrons is quite low compared to the alphainduced scintillation one, which lead to a low sensitivity to gamma background.…”

Comparison of 8Li and 9Li Spin Relaxation in SrTiO3 and Pt: A Means to Distinguish Magnetic and Electric Quadrupolar Sources of Relaxation

“…ZnS is a cubic material in the sphalerite form. When doped with Ag, the resulting compound is known to be an extremely bright scintillator [15] (∼ 95, 000 ph/MeV). Commonly it is used in a polycrystalline form, sprayed as a powder on a surface.…”