| Popis: |
The search of the annual modulation in the detection rates that could evidence the presence of galactic dark matter energy depositions in the detector is of utmost interest after DAMA/LIBRA positive result [1] and recent hints from other experiments like CDMS [2] and CoGeNT [3]. Another experiment using the same target that DAMA/LIBRA is required in order to confirm the effect: ANAIS is a project to be carried out at the Canfranc Underground Laboratory with such a goal. The complete experiment proposed will use about 250 kg of NaI(Tl) crystals to study the expected annual modulation in the galactic dark matter signal. Very high radiopurity levels are required; particularly, very low potassium content in the crystals. For this goal new powder purification techniques are being developed. In parallel, a 9.6 kg NaI(Tl) prototype, called ANAIS-0, has been tested underground. With ANAIS-0, low energy events coming from external gamma calibration sources and from the 3.2 keV line of the 40 K internal contamination are studied to develop different low energy estimators and parameters for noise rejection. Tests of different photomultipliers with or without light guides are ongoing in order to determine the best compromise between high light collection and low background. |
