NaIAD (NaI Advanced Detector)
The NaIAD experiment ran from 2000 to 2003 and currently holds the worlds best limit on the spin-dependent WIMP-nucleon cross-section.
Schematic of the NaIAD detector.
NaIAD used a sodium iodide (NaI) crystal scintillator target, with a total mass of 46 kg, encapsulated in 10 mm thick polytetrafluoroethylene (PTFE) reflector cages. The detector was kept at a running temperature of circa 10 degrees C with chilled water running through copper coils surrounding the detector.
Photos of the NaIAD detector.
The NaIAD detector was shielded from sources of particle background by lead, copper, wax and polypropylene.
Example pulse from NaIAD.
Low background photomultiplier tubes (PMTs) at the end of light guides running through the PTFE were used for readout. Scintillation pulses generated when nuclei or electrons recoil from scattering were detected by the PMTs and converted to an equivalent energy value for analysis, with factore calculated from calibration data.
Pulse shape discrimination from NaIAD.