WARP
Collaboration
Laboratory: Gran
Sasso National Laboratory
1. Goal of the experiment
The experiment aims at the unambiguous identification of Dark
Matter candidates (WIMPS) by means of the detection of nuclear
recoils in liquid argon. The proposed technique combines the
experience and the tools developed for the ICARUS experiment for
handling ultra-purified liquid argon and for detecting the argon
scintillation light with the technique developed, also by the
ICARUS Collaboration, for detecting and discriminating nuclear
recoils in liquid xenon.
2.
Activities during 2002
During 2002 the small prototype of the two-phase chamber was
reconfigured, by adding a waveshifing/reflector layer (to
increase the light collection efficiency and to minimize dead
zones potentially source of fake signals) and by reducing the
active volume. Several calibration and test runs were made using
both X-rays, g and neutron sources. Very good light collection
efficiency was obtained (superior to the best value reached with
xenon chambers) with correspondingly good energy resolution.
Highly efficient discrimination between X-rays and nuclear recoil
events (from neutrons interactions) was demonstrated down to very
low recoil energy thresholds (30 keV or less).
Milestones 2003
This development activity is currently under examination by the CSN2
(If approved by the CSN2 and by the LNGS authorities, the activity will proceed with the run of the small prototype in LNGS mainly for neutron background measurements. A larger prototype will also be built also dedicated to background studies both from the environment and from construction materials).
3. INFN contribution to the experiment in
terms of manpower and financial support
The activity is currently carried on as part of the R&D for
the ICARUS experiment on scintillation light detection both in
the INFN Pavia laboratory and in CERN. Financial support is
completely given by INFN through INFN funding of the general
activities of the Pavia Gruppo II (expense chapter Dotazioni) and
as part of the contribution to the ICARUS activity. People
actively working on the subject are from the INFN Pavia group and
from the Italian components of the Icarus Collaboration (from
Padova and Torino) working at CERN. The involved researchers are
11 (3.6 FTE) with the technical support from the partecipating
Sezioni.
4. Publications in refereed journals:
0
5. Conferences talks: 0
6. Number of undergraduate and doctoral
thesis on the experiment: 0
7. Leadership role in the experiment
C. Rubbia (Universita' degli Studi di Pavia ed INFN Sezione
di Pavia) Spokesman
8. Innovative instruments
9. Competing experiments
The project is in competition with the many experiments working
on Dark Matter (DAMA, CUORE, etc.)