(1991 - 1996)

Development of the H1 Silicon Detector Readout Module

The large number of readout channels and the high bunch-crossing frequency of HERA of 10.4 MHz demanded a novel readout architecture which included front end pipelining, signal processing and data reduction at a very early stage. I was a member of the H1 silicon detector group and worked on the development of the versatile readout module OnSiRoC (Online Silicon Readout Controller). The OnSiRoC included all necessary features to operate the silicon detectors such as the power supplies for the bias voltages of the silicon wafers and the operating voltages of the front end electronics. It also contained the controller for the front end readout chips, fast digitization and data sparsification. The OnSiRoc board is described in detail in ``Online Readout and Control Unit for High Speed / High Resolution Readout of Silicon Tracking Detectors", J. Buerger et al., Nucl.Instrum.Meth. A386, 269 (1997). I assumed a leading role in the development of the OnSiRoC software. To test the performance of OnSiRoC prototypes in a realistic environment built a complete readout chain. This included prototype strip detectors and front end hybrids of the backward H1 silicon detector, a trigger logic and a readout system consisting of an OnSiRoC module and a desktop computer to store the data. I worked on the design and the performance tests of the strip detectors and the front end hybrids and I analyzed data from a radioactive source and from cosmic muons. I studied the impact of the precision of the H1 silicon detectors on physics analyses with simulated events to explore the improvement of the charged particle trajectory resolution in the study of heavy meson decays. I received my PhD degree from the University of Hamburg in June 1996. A copy of my PhD thesis (in German) can be found here.

H1 Drift Chamber Calibration Development

In the H1 tracking group I gained experience in drift chamber hardware and readout and track reconstruction software. My work included the development of algorithms for calibration, position and energy loss measurements and charged particle trajectory fitting. The topic of my diploma thesis was the calibration of the z position measurement (by charge division) and the energy loss measurement (dE/dx) of the central jet chamber of the H1 detector. These calibrations required efficient handling of large data samples and the development of fast algorithms. I received my physics diploma degree from the University of Hamburg in October 1992.