Results
C2ClF5
|
Fig. 1: SIMPLE “lite” [R-115] |
A
prototype measurement conducted in 1999, consisting of one 9.2 g SDD operated
between 0-14 oC at 2 bar for 16 days, resulted in exclusion limits
down to ~ 10 pb. The experiment suffered from low statistical power, and from
signal backgrounds arising from pressure microleaks in the module capping. The most recent
results were obtained with four SDDs run
for a total exposure of 0.42 kgd. The result yields ~ a factor 10 improvement
in the previously-reported results, and — despite the low exposure — provided
restrictions on the allowed phase space of spin-dependent coupling strengths
competitive with those from the significantly larger exposure searches if one
considers exposures. |
|
Fig. 2: spin-dependent SIMPLE “lite” results in comparison with leading experiments |
Current SIMPLE spin-dependent
limit, in the model-independent representation (the a’s are the WIMP-proton
and WIMP-neutron coupling strengths), in comparison with other dark matter
search projects; the allowed region (crosshatched) is defined by the
intersect NAIAD and CDMS. Note that, in terms of ap-sensitivity,
SIMPLE is surpassed only by NAIAD at 44.9 kgy exposure (DAMA/NaI is shown as
shaded). A 3 kgd experiment (25 detectors, 300 g active mass) is currently in preparation for execution early in 2007, with funding requested for a 30-100 kgd (100 detectors, 1 kg) exposure later in the year. |
Fig.
2: spin-independent SIMPLE “lite” results, in comparison with leading
experiments |
CF3I
|
Fig. 3:
preliminary and projected spin-independent CF3I SDD exclusions. |
Two
prototype SDDs, of 6 and 19 g mass, were operated for ~4 days during a LSBB
mission in November 2006. The heavier device prototype failed as a result of
fractures, but provided coincidence information to the first device signal
filtering. The
temperature controller failed at the measurement outset, restricting the
experiment to 16ºC with impact in the spin-independent sector as shown by the
solid line in the Figure (the dashed continuation to low MW suggests
the result which would have been obtained had the temperature been at 37ºC (8
keV recoil threshold) as programmed. |
Fig. 4:
preliminary and projected spin- Dependent CF3I SDD exclusions |
