Low energy events in NaI(Tl) scintillators. ANAIS status and prospects
Low energy events in NaI(Tl) scintillators. ANAIS status and prospects
PoS(IDM2010)020
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 40K 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.
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 40K 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.