OUR
FINAL
RESULT 2006:
Nr. 1 - LESSONS after LONG TERM ....
Nr. 2 - Long Term ...
Nr. 1: Please click here to print the
pdf file
of our LESSONS
Physics Scripta T 127 (2007) 52-53:
I.V. Krivosheina and H.V. Klapdor-Kleingrothaus
"Lessons After 3 Years of Running GENIUS-TF in Gran-Sasso"
-------- Abstract --------
After operation of GENIUS-TF
over three
years with finally six naked Ge detectors (15 kg) in liquid nitrogen
in Gran Sasso we realize
serious problems
for realization of a full-size GENIUS-like experiment:
1. Background from
222Rn diffusing into the setup, on a level
far beyond the expectation.
2. Limited long-term stability of naked
detectors in liquid nitrogen.
None of the six detectors is running after three years with the nominal
leakage current.
Three of the six detectors do not work any more at all. The HDMS
(Heidelberg Dark Matter Search) setup at LNGS,
operates the first enriched
73Ge detector worldwide,
and looks for spin-dependent WIMP-nucleon coupling at the Gran Sasso
Underground Laboratory. The results (85.48 kg d)
improve the best present existing limits
on the WIMP-neutron spin-dependent cross section
(obtained from
129Xe) for low WIMP masses
(see Klapdor-Kleingrothaus, I.V. Krivosheina and C. Tomei, Phys. Lett. B
609 (2005) 226-31).
-------- Abstract --------
Right - The six contacted naked Ge detectors."
Nr. 2 : Here You will find another
article -
pdf file of the new article
Nucl. Instrum. Meth. A 566 (2006) 472-476
H.V. Klapdor-Kleingrothaus and I.V. Krivosheina
"Status of GENIUS-TF-II and TF-III:
The Long-Term Stability of Naked Detectors in Liquid Nitrogen."
-------- Abstract --------
GENIUS-TF-II is a setup of
six
naked high purity Ge detectors
(15 kg) in liquid nitrogen in Gran Sasso.
It has been installed in October, 2004 - after the first four naked Ge
detectors had been installed on May 5, 2003 (GENIUS-TF-I).
The GENIUS-Test-Facility (GENIUS-TF) is
the first
and up to now
only
setup ever testing the novel technique aiming at extreme
background reduction in search for rare decays in particular underground.
The goal of GENIUS-TF
was to test
some key operational parameters of the full GENIUS project proposal in
1997 \cite{KK-Bey97,HVKK-Prop87,Hel-KK-Genius97,KK-Hir97-Genius,KK-H-H-97,CERN87}.
Simultaneous physical goal is to search for the annual modulation of the
Dark Matter signal \cite{NIM02-TF,NIM-Mod03}.
After operation of GENIUS-TF over three years with finally six naked Ge
detectors (15 kg) in liquid nitrogen
in Gran Sasso we realize serious problems for realization of a full-size
GENIUS-like experiment:
1. Background from
222Rn
diffusing into the setup, on a level far beyond the expectation.
2. Limited long-term stability of naked detectors
in liquid nitrogen as result of increasing leakage current.
None of the six detectors is running after three years with the nominal
leakage current.
Three of the six detectors do not work any more at all.
The results of our three years of
investigation of the long-term stability
casts serious doubt on the
possibility to perform a full GENIUS project - or its copies GERDA or
CAMEO/GEM. ----------------
"Schematic view of a naked Ge detector for the GENIUS-TF experiment and its holder construction."
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Last modification (I.Krivosheina): 11/11/2007