1. NaIAD-Sodium Iodide Advanced Detector (UKDMC)
NaIAD operation has now ceased.
Analysis of final 23 kg × years of data is underway.
Single NaIAD Module
Until November 2003 NaIAD was running with 7 crystals
with a total mass of 56 kg. First published limit was with 10.6 kg ×years of data.
Second preliminary limit (shown below) was with 20.3 kg ×years of data.
With improved crystal polishing procedure the ‘bump’ seen in previous
data (due to surface contamination) has now disappeared.
Figure shows TCD (10-15 keV) for DM70 before and after polishing.
DM70
(Courtesy of Saclay Group)
Before
After
Encapsulated Crystal
NaIAD array with neutron shielding
Analysis technique is based on Pulse Shape Discrimination to
identify neutron and electron populations.
New noise reduction techniques enable better fitting of TCDs.
Most recent NaIAD limit with 20.3 kg×years of data.
Analysis of final 23 kg × years of data is underway.
NaIAD module in coffin with
Copper and lead shielding
Electron and neutron time
constants as a function of
energy.
Distribution width as a
function of energy.