Comparison of New Simple Methods in Fabricating ZnS(Ag) Scintillators for Detecting Alpha Particles

Abstract

The silver-activated zinc sulfide, ZnS(Ag), sensor to detect alpha-particles is normally fabricated by means of heat-melting or epoxy mixing spread. However, the fabrication process is very complicated so that it creates high costs and requires special high-tech equipment to manufacture the detector. For this reason, we have developed a new fabrication method which has the advantages of process simplicity and also high efficiency. The alpha particle response of the detector manufactured by the new spreading method was evaluated at varied thicknesses of ZnS(Ag) and the detection efficiency was better than for other methods like liquid brush method with an Am-241 alpha radiation source. Compared to conventional ZnS(Ag) detectors, the new detector shows a good detection efficiency, and its simple and low cost design makes it an economical and commercial alternative to more expensive alpha survey instruments.

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

“…The ZnS:Ag and LiF/ZnS:Ag commercial powder screens were ~250 to 500 μm thick. These screens are typically produced by embedding ZnS and LiF powders in a polymer matrix; the EJ-426 includes LiF for thermal neutron sensitivity [6]. In this paper, detailed luminescence data are shown for the three CVD samples and powder phosphor screens.…”

“…It is generally believed that ZnS:Ag scintillator is only suitable for α-particle sensing because commercial powders scatter the emission light in thicknesses greater than ~100 μm [4]. Additionally, 6 LiF/ZnS:Ag is used in thin opaque screens for thermal neutron detection with good gamma rejection [5][6][7][8], a technology with origins from 1960 [3]. Thermal neutrons interact with the 6 Li via the 6 Li(n,α) 3 H reaction, and the resultant charged particles produce light in the ZnS.…”

“…Additionally, 6 LiF/ZnS:Ag is used in thin opaque screens for thermal neutron detection with good gamma rejection [5][6][7][8], a technology with origins from 1960 [3]. Thermal neutrons interact with the 6 Li via the 6 Li(n,α) 3 H reaction, and the resultant charged particles produce light in the ZnS. Recently, ZnS has been combined with 10 B 2 O 3 in screens [9] or as a borate glass [10] to detect thermal neutrons using the 10 B(n,α) 7 Li reaction.…”

Caracterización teórico-experimental de nuevos sistemas de detección de neutrones para el control de mercancías en fronteras y puntos críticos

“…Se caracteriza por tener una alta eficiencia de centelleo, comparable con el NaI(Tl), utilizado básicamente para detección de partículas  Se dispone solo de polvo policristalino y La detección de tráfico ilícito de materiales nucleares 2-65 debido a su opacidad, solo puede utilizarse en capas menores a 25 mg/cm 2 ya que tiende a absorber su propia luminiscencia; capas mayores pueden ser inutilizables, o bien encontrar la relación espesor más cantidad de 6 Li/ 10 B para detección de neutrones (Koontz et al, 1954). En adición este puede ser utilizado para la detección de neutrones rápidos y térmicos si se añade 6 Li o 10 B (Lee et al, 2011).…”

“…; en la Figura 22 se observa el arreglo geométrico básico de un detector de ZnS(Ag), y en la Tabla 12(Lee et al, 2011) las características principales del centelleador ZnS(Ag).En el PNNL se han realizado diversos estudios sobre alternativas interesantes de reemplazo de los detectores de3 He. En(Kouzes and Ely, 2010) se hace el análisis del detector de 6 Li+ZnS(Ag) de la marca Symmetrica; de este detector se realizó el estudio en el año 2010 de un prototipo, Figura 24, llamado NNS1000, reportando una eficiencia de 1,02 cps/ng de 252 Cf como prototipo, por lo que habría que escalarlo (a las dimensiones del SAI portal) a medidas similares a las de reemplazo físico de los detectores de3 He, estimando que se podría conseguir una eficiencia de detección de unas ~4 cps/ng252 Cf a 200 cm (Symmetrica, 2010); en la Tabla 13 se observa en nivel de rechazo gamma a diferentes campos de mR/h.…”