Project number: P09/02
Status Report (October 2003)
Project Title: COBRA
Group Leader: K. Zuber: University of Oxford (UK)
Researchers: K. Zuber: University of Oxford (UK)
H. Kiel, C. Goessing, D. Muenstermann, S. Ohel, T. Villet, K. Warda: University of Dortmund (Germany)
Delivered access (filled by TARI administration): 44 man-days
Status report :
The aim of the study is to measure the reiliability of CdTe detectors for low level applications, especially neutrinoless double beta decay and the search for dark matter and rare nuclear decays. A first setup was installed mid of May 2003 which has been updated with a new detector set in mid of August 2003. However, a severe problem arose, because the planned installation could not be done as planned in a COBRA container, because the container has not been ready (and unfortunately still isn’t). Hence, an emergency solution has been found in installing the setup in the LUNA1 building, which is restricting the methods we could apply. Nevertheless first interesting results have been obtained. The first background measurements indicate that in the neutrinoless double beta decay region a factor 3 improvement has been obtained with respect to the surface. However, various options for further improvements exist.
Future Programs (filled by group leader):
Due to the unfortunate situation we plan to move to the place originally forseen for COBRA. Rough estimates point towards the end of 2003. Then various improvements will be installed.
First of all, additional lead will be used to enhance the shielding against gamma rays. In addition, a nitrogen flushing to keep the air outside the experiment will be installed. Furthermore, a neutron shield of boron loaded polyethylen plates will be placed around the apparatus. This is very important, because neutrons are one of the major background sources. In this configuration we plan to run for some time to obtain reasonable background spectra. Meanwhile, we’re working on a more sophisticated data acquisition system, being faster and offer additional measurement options. The current plan is to install it in spring 2004. In addition, we work on the design of a new detector array, implementing the experience from the current data taking period. This will also include a larger number of detectors, going from the current 4 detectors to at least 16. Currently considerations and discussions are on their way to install to alternative detector types in the second half of 2004, namely CdTe with electron-hole readout (the current detector type signal relies only on electrons) and a pixelised CdTe.
Group Leader: K. Zuber: University of Oxford (UK)
Researchers: K. Zuber: University of Oxford (UK)
H. Kiel, C. Goessing, D. Muenstermann, S. Ohel, T. Villet, K. Warda: University of Dortmund (Germany)
Delivered access (filled by TARI administration): 44 man-days
Status report :
The aim of the study is to measure the reiliability of CdTe detectors for low level applications, especially neutrinoless double beta decay and the search for dark matter and rare nuclear decays. A first setup was installed mid of May 2003 which has been updated with a new detector set in mid of August 2003. However, a severe problem arose, because the planned installation could not be done as planned in a COBRA container, because the container has not been ready (and unfortunately still isn’t). Hence, an emergency solution has been found in installing the setup in the LUNA1 building, which is restricting the methods we could apply. Nevertheless first interesting results have been obtained. The first background measurements indicate that in the neutrinoless double beta decay region a factor 3 improvement has been obtained with respect to the surface. However, various options for further improvements exist.
Future Programs (filled by group leader):
Due to the unfortunate situation we plan to move to the place originally forseen for COBRA. Rough estimates point towards the end of 2003. Then various improvements will be installed.
First of all, additional lead will be used to enhance the shielding against gamma rays. In addition, a nitrogen flushing to keep the air outside the experiment will be installed. Furthermore, a neutron shield of boron loaded polyethylen plates will be placed around the apparatus. This is very important, because neutrons are one of the major background sources. In this configuration we plan to run for some time to obtain reasonable background spectra. Meanwhile, we’re working on a more sophisticated data acquisition system, being faster and offer additional measurement options. The current plan is to install it in spring 2004. In addition, we work on the design of a new detector array, implementing the experience from the current data taking period. This will also include a larger number of detectors, going from the current 4 detectors to at least 16. Currently considerations and discussions are on their way to install to alternative detector types in the second half of 2004, namely CdTe with electron-hole readout (the current detector type signal relies only on electrons) and a pixelised CdTe.