Figure 2:3 dimensional cut through Euroball III
Figure 2:3 dimensional cut through Euroball III
The Euroball III array will be a full 4 pi ball of gamma-ray detectors consisting of three sections, two end caps around the beam axis and a central section around 90 degree. In the backward end cap there will be 15 Cluster Ge detectors with their associated BGO suppression shields. In the central section will be 26 of the Eurogam phase II Clover detectors. The forward end cap will consist of 30 phase I detectors using the BGO shields from Eurogam phase I and Ge detectors from both Eurogam and GASP. The performance of the array will be improved at a second stage by replacing some detectors in the central section with up to 6 enhanced performance detectors, such as the Segmented Clover detector.
The full energy efficiency in 4 pi at 1.33 MeV gamma-energy amounts to 1.6 percent (standard) + 3.8 percent (Clover) + 4.8 percent (Cluster) = 10.2 percent. The effective P/T-ratio is about 60 percent and the mean energy resolution 5.6 keV assuming a velocity of v/c = 4 percent for the gamma emitting nucleus.
Euroball III can be used in conjunction with ancillary detectors, such as charged particle detector arrays and neutron detectors for specific experiments. A number of such devices are being constructed or adopted for use with Euroball. This work is coordinated within the Euroball ancillary detector working group.
A VXI electronics system will be used for Euroball. Electronics from Eurogam will be used for the detectors in the forward and central sections after some upgrade of the cards for parallel read out. New VXI cards will be developed for the Cluster and Segmented Clover detectors. In a later stage these cards will incorporate pulse processing ADCs. In order to fully exploit the possibilities of Euroball, used both alone and also coupled to a number of ancillary detectors, a new data acquisition system [1] capable to handle a data throughput of at least 20 Mbyte/s is being developed. This system uses high speed switched networks for data transfer and workstations for event building and online analysis.
The first site for Euroball III will be LNL Legnaro, Italy. A new experimental hall has been built in 1995 to host the array. The installation of beam lines, mechanical structure, liquid nitrogen supply and the cabling is foreseen for the first half of 1996 to enable the set-up of the detectors and the commissioning of the various components in automn 1996. The experimental phase is planned to start in January 1997 and will last for 14 to 16 months. The second site will be CRN, Strasbourg where the experiments will commence in July 1997 again for a period of 14 to 16 months.
[1] A Data Acquisition System for Euroball III, G. Maron, V. Pucknell, gzip-postscript, 40kB
