1. DESPEC A Algora IFIC (Valencia) for the Ge array working group

2. DESPEC (DEcay SPECtroscopy) Spokesperson: Dr. Berta Rubio Goal: study of the radioactive beams coming from the SFRS. Tasks: stop the beams, implantation and study Collaboration: ≥36 Institutes Basic Instrumentation:  Ge ball (Cube in reality), TAS  Implantation detectors (DSSD detectors)  Neutron detectors  Detector array for measurements of fast timing  Setup to measure electromagnetic moments Conceptual design

3. Basic experiments Requirements Beta decay experiments in the classical sense (trigger can be provided by the signals left by the betas in the implantation detector) High gamma efficiency, background reduction, good E resolution, and position resolution (tracking can be used to improve the peak to total ratio, and probably to reduce background) Isomer decay experiments Imaging techniques can be used to track the position of the decay and reduce background DESPEC

4. Possible Ge arrays Detectors24 No. of planars (stack) 3 No. de strips (planar) 8 x 8 No. of electronic channels 1152 Detectors6 ó 8 Preamps per detector52 (48 +4) Number of channels312 (416) 8x24 cm 2

5. Planar Array Composite detectors: Ge planar detectors of 72x72x22 mm3, active volume of 68x68x22 mm3. Guard ring of 2 mm thickness. Al capsule of 1.5 mm thickness. Al-Ge, and Ge-Ge distance 3mm. Geant4 simulations have been performed (0.1 mm cuts and low energy physics for the different setups)

6. Modified Tigress Array (backup solution) clover 4x60x90 seg 48 Size of the individual crystals: Diameter 60 mm before shaping Length of the crystal 90 mm Additional details: Longitudinal segmentation x4 Transversal segmentation x3 (25,25,40) Separation of less than 7 mm from the exterior surface of the Al cap Separation between the crystals less than 0.7 mm

7. Synergies with the Network: research and development Collaboration with AGATA (we are already in contact with the Padova group) for the use and development of codes to apply tracking techniques for the DESPEC array Collaboration with AGATA (we are already in contact with the Padova group) for the use and development of codes to apply tracking techniques for the DESPEC array Pulse shape analysis (fundamental for our working group, collaboration is needed) Pulse shape analysis (fundamental for our working group, collaboration is needed) Development of detectors (planar prototype, TAS) Development of detectors (planar prototype, TAS) Applications of Monte Carlo techniques (we can train people in this field) Applications of Monte Carlo techniques (we can train people in this field) Application of imaging techniques Application of imaging techniques

8. Efficiency assuming full tracking!! E(MeV)Eff(peak)P/TEff(tot) 0.1047.691.253.7 0.2538.767.557.4 0.5027.249.755.6 1.0019.038.050.3 2.0012.728.944.5 5.006.516.639.6 10.003.48.739.7E(MeV)Eff(peak)P/TEff(tot)0.1036.478.546.3 0.2530.766.546.2 0.5023.553.943.6 1.0018.044.240.7 2.0012.935.336.6 5.007.121.732.8 10.004.014.028.7 Planar setup Clover setup (6 clovers)

9. A Monte Carlo code has been also developed to evaluate the tracking efficiency of the different Ge arrays (collaboration with the AGATA group of Padova) A.Algora et al GSI annual report 2006