Prof.Dr.H.V.Klapdor-Kleingrothaus

Teilchenphysik ohne Beschleuniger (Non Accelerator Particle Physics)

Experimental and theoretical research in the areas of
Double Beta Decay, Dark Matter Searches and Physics beyond the Standard Model

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 --------


GENIUS-TF-Stand 2006
"View from the top on the GENIUS-TF-II setup during installation in October 2004.
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.
----------------


GENIUS-TF-Stand 2006
"Schematic view of a naked Ge detector for the GENIUS-TF experiment and its holder construction."

Back to the OUR SUPER FINAL Result 2006-2007

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Back to the OUR NEW-'OLD'Result 2003-2004


Last modification (I.Krivosheina): 11/11/2007