Dr. Johannes Stiller

In einem Interview für absolventa.de habe ich meinen Einstieg und meine Erfahrung bei ZF beschrieben: https://www.absolventa.de/interviews/berufseinsteiger/berufseinstieg-bei-zf-erfahrungen-v2352

I particularly enjoyed the international diversity, especially during my frequent travels to CERN and many specialized presentations in the collaboration. It gave me the opportunity to integrate myself in a diverse group of people, necessary to succeed in such projects. In addition to my thesis work, I was able to work directly on the ALICE experiment hardware. These projects qualified me as detector on-call expert and as remote support for the safe and reliable detector operation in 24-hour shifts.

With the completion of the ALICE Transition Radiation Detector, also the low voltage infrastructure of the detector had to be fully commissioned. Each connection of the about 88 installed low voltage power supplies (delivering up to 150 A, 5 V) was tested and safely connected to withstand the impact of the large magnetic field, with individual cable length of around 100 meters on the experimental site. I established complete and detailed documentation for easy maintenance of the system.

In order to prevent loss of data during the actual data acquisition, the Ethernet control of the detector was developed redundant against individual Ethernet switch failures and local power outages. I took over this task from my precursor and finalized the full commissioning of the system. This involved coordination of small groups of (Ph.D.) students as well as actual installation and connection work.

My tasks involved planning of the actual duration of the data taking as well as of necessary statistical precision. Further, I was responsible of continuously monitoring the data quality during the actual acquisition and coordinate immediate reconstruction of the data in analyzable format. As the detector was extended by additional devices and for monitoring of the calibration quality, this task was repeated in 2015. During this successful calibration campaign I supervised a Ph.D. student.

During this time, I supported the technical coordinator of the ALICE Transition Radiation Detector in planning of work tasks and management of small groups of technicians and (Ph.D.) students for completing and commissioning the detector. This also included full connection of infrastructural services, such as power and readout of five new detector modules, each about five meters long and 1.8 tons heavy. In addition, several older detectors had to be disconnected, reworked and eventually reconnected.

During my second internship in Berkeley, I continued the bench testing of the readout system of the BRAN detector. I was further involved in systematic tests of an unexploded ordnance detector, including calibration runs.

During the time at the Berkeley Lab, I created and performed simulations of the obtained data with the BRAN detector in a test beam run at CERN and also assembled three (out of four) devices for the operation at the Large Hadron Collider at CERN. My tasks concluded in detailed documentation. For the final presentation at the meeting of the California Section of the American Physical Society, I was awarded the Steven Chu Award for Best Undergraduate Research.

Rare signal analysis in abundant background for future detectors; Optimization of multi-dimensional selection criteria; High statistical precision with new fast parameterized Monte Carlo simulations based on Kalman filtering; Reproduces former simulations while outperforming in computational speed

Thesis Title: Gain Calibration of the ALICE TRD using the Decay of 83mKr and Alignment of the ALICE TRD (available at http://www.physi.uni-heidelberg.de/Publications/)