M.Sc. degree
Groningen University, the Netherlands

Elmaddin Guliyev

Supervisor: Prof. dr. Herbert Loehner

Keywords:

• Charmonium
• ASIC
• Detector
• Anti-Proton

Abstract:

In this thesis, the concept of a trigger-less data acquisition is pursued and a prototype system based on a commercial Sampling ADC has been developed. It is shown, that such type of data readout allows to reach better performance in terms of noise level, energy and time resolutions. In this way the requirements described in the PANDA EMC Technical Design Report [7] could be met. In addition, the digitization and continuous on-line processing of the front-end preamplifier/shaper signals prevent dead time. This feature allows to run the DAQ at high rate.

In the future, the prototype of the trigger-less DAQ will be tested with high energy photon beams using the Proto60 EMC prototype. At present, the performance of the trigger less DAQ is investigated by comparing the results with those from an off-line processing of data taken during test measurements.

We have shown, that the DAQ can on-line process pulses of different shapes, such as charge-integrating preamplifier pulses as well as shaped pulses. Therefore, the developed readout can be applied for a very wide range of experiments.

The VHDL code of the feature-extraction algorithm will be open under General Public License (GPL), which will allow the free use for other projects. The commercial company STRUCK [48] is interested in porting of our firmware to other modules [86]. STRUCK has already received one request from an experimental group at Darmstadt to have our newly developed features implemented. Another possible application of our DAQ concept is the construction and readout of a luminosity-monitor detector at the BESIII (Beijing Electron Spectrometer) experiment. The luminosity achieved at the BEP-II accelerator [87] has reached 3·1032 cm-2s -1. The on-line monitor of the luminosity is required for precise monitoring of the stability of the beam intensity in order to determine precisely the cross sections of physics processes. The main challenge of the on-line monitoring of luminosity is to overcome limitations due to dead time in the DAQ introduced by high interaction rates.

The trigger-less readout will provide the most efficient way of using the hit information with minimal losses. The setup will require only a few single crystals to detect the incoming electrons or positrons at high rates. To avoid pile-up of the incoming pulses, the width of the MWD pulses should be reduced as much as possible. The data acquisition concept developed at the Kernfysisch Versneller Instituut can be used at different experimental setups operated at various event rates.