Multilayer Surface Detector for Ultracold Neutrons (UCN)
A multilayer surface detector for Ultracold Neutrons was created for measurements to determine neutron lifespan. This is a multilayer solid state detector which relies on a topmost Boron-10 layer to capture ultra cold neutrons. The ZnS:Ag layer below detects neutron capture charge release and a photomultiplier detects the light generated by this neutron capture.
"The multilayer 10B surface detector for UCNs consists of a thin 10B top layer
supported by a luminescent layer of ZnS:Ag. At least one of the charged particles α o
7Li generated from the neutron capture slows down or stops in the ZnS:Ag layer and
emits light. A light-guide or a transparent window is used to transmit the light to a
photomultiplier tube (PMT). A 10B thickness of 100 nm and a ZnS:Ag thickness of a
few microns are sufficient." A Multilayer Surface Detector for Ultracold Neutrons
(Link below)
Left: Boron-10 coated commercial silver-doped ZnS screens are used to capture
ultracold neutrons directly; Right: A large area detector prototype is being examined in
a light-tight box. An array of wavelength-shifting scintillator fibers is used to collect
light from a 0.5 m by 0.3 m surface. (Department of Energy)
Further Information
A Large-Area Detector for Fundamental Neutron ScienceWang, et al. "A Multilayer Surface Detector for Ultracold Neutrons.” Nuclear Instruments and Methods in Physics, Oct. 2015.
