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

GENIUS-TF: A Test Facility for the GENIUS-Project


The first four naked high-purity Germanium detectors were installed successfully in liquid nitrogen in the GENIUS-Test-Facility in the GRAN SASSO Underground Laboratory on May 5, 2003. This is the first time ever that this novel technique aiming at extreme background reduction in search for rare decays is going to be tested underground. First operational parameters are presented.

The successful team after installation of the detectors, on May 5, 2003, GRAN SASSO, ITALY.
From left to right: Irina Krivosheina,
Hans Volker Klapdor-Kleingrothaus
(Spokesman of the Heidelberg-Moscow experiment and also speaker of this collaboration),
Claudia Tomei and Herbert Strecker from the Max Planck Institute for Nuclear Physics in Heidelberg.

The first contacted four naked detectors in the low-level holder in which they are put into the shielded liquid nitrogen container of GENIUS-TF.

Cross section of the setup (GENIUS-TF-I).

Figs. show two spectra measured a few days after installation. A first spectrum measured with a 60Co source outside the setup, and the 133Ba source inside. The resolution at this moment (two days after installation) is 3 keV in the 1330 keV region. The first background spectrum measured with detector 2 over 40 hours without shield of the setup to the top.

Collaboration for GENIUS-TF

Design of the GENIUS-TF setup. The HPGe crystals are located inside a polystyrene box, which is serving as the liquid nitrogen dewar. To minimize the influence of the intrinsic polystyrene impurities, an additional inner shielding layer of zone-refined Germanium is used. The box is surrounded by a subsequent layer of low-level lead or copper which is enclosed in a borated polyethylene shield.

We propose to install a setup with up to 14 HPGe-detectors corresponding to an active mass of ~ 40 kg on small scale. The 14 detectors would provide one module (or a modular part) of the final support structure for GENIUS. The desing is shown in Figure.

The background considerations and simulations suggest that a reduction of the background by a factor of ~ 5 with respect to the HEIDELBERG-MOSCOW experiment can be attained with the proposed setup. This would lead to a background index of ~ 4 counts/(kg keV y) for the GENIUS-TF.

The GENIUS-TF could clearly identify the annual modulation signature favored by the recent DAMA data within some years.

For more information, please look into articles:

H.V. Klapdor-Kleingrothaus
" 'Naked' crystals go underground" , hep-ph/ /0307???,
CERN CUERIER 43, Number 6 , Page 9 (2003)

H.V. Klapdor-Kleingrothaus, I. V. Krivosheina, H. Strecker and C. Tomei
"First 10 kg of naked Germanium detectors in liquid nitrogen installed in the GENIUS-Test-Facility" ,
hep-ph/ /0307???, Nucl. Instrum. Meth. A 511, Issue 3 (2003) 341-346

H.V. Klapdor-Kleingrothaus and C. Tomei
85Kr and 39Ar Background in GENIUS", hep-ph/0306258,
Nucl. Instrum. Meth. A 508, Issue 3 (2003) 337-342

C. Tomei, A. Dietz, I. Krivosheina and H.V. Klapdor-Kleingrothaus
"Searching for the Annual Modulation of Dark Matter Signal with the GENIUS-TF Experiment" , hep-ph/ 0306257,
Nucl. Instrum. Meth. A 508, Issue 3 (2003) 343 - 352

T. Kihm, V.F. Bobrakov, H.V. Klapdor-Kleingrothaus
"A digital multi-channel spectroscopy system with 100 MHz flash ADC module for the GENIUS-TF and GENIUS projects" , hep-ph/0302236,
Nucl. Instrum. Meth.
A 498 (2002) 334-339

H.V. Klapdor-Kleingrothaus
"Search for Dark Matter by GENIUS-TF and GENIUS"
hep-ph/0206250, Nucl. Phys. Proc. Suppl. 110 (2002) 58 - 60

H.V. Klapdor-Kleingrothaus, L. Baudis, A. Dietz, G. Heusser, B. Majorovits, H. Strecker, "GENIUS-TF: A TEST FACILITY FOR THE GENIUS PROJECT" hep-ex/0012022,
Nucl. Instrum. Meth. A 481 (2002) 149-159

H.V. Klapdor-Kleingrothaus, L. Baudis, A. Dietz, G. Heusser, I. Krivosheina, B. Majorovits, H. Strecker , H. Tu, S.T. Belyaev, V.I. Lebedev and coworkers "GENIUS-TF: A TEST FACILITY for the GENIUS-Project", MPI - REPORT (2000)


Please ask for the GENIUS proposal. We would be happy to send you a hardcopy.


Last Modification: 26.08.2009 Created: 20/10/2000