JINST Instrumentation Theses Archive

Ph.D. degree thesis
accepted by Max-Planck-Institut für Physik, Germany, in 2007

Adam Nepomuk Otte

Supervisor: Eckart Lorenz

Observation of VHE Gamma-Rays from the Vicinity of magnetized Neutron Stars and Development of new Photon-Detectors for Future Ground based Gamma-Ray Detectors

 Keywords:

• Photon detectors for UV, visible and IR photons (solid-state) (PIN diodes, APDs, Si-PMTs, CCDs, EBCCDs etc)

 Abstract:
This thesis reports about the observation of VHE-gamma-ray emission from the Crab, PSR B1951+32 and PSR B1957+20 with the MAGIC telescope.

For the first time, the emission of the Crab nebula has been studied in detail in the energy domain between 60 GeV and 400 GeV. The measured energy spectrum of the nebula deviates from a simple power law. The IC-peak has been determined to be at 77+-47 GeV. Within the resolution of the experiment the emission from the nebula appears pointlike and steady.

The Crab pulsar was detected in optical wavelengths with a modified pixel in the center of the MAGIC camera. The pulsar was not detected in gamma-rays, while a 2.9 sigma excess was found at the phase position of the interpulse, in agreement with EGRET observations above 5 GeV. The cutoff energy of the pulsar was constrained to be <27 GeV, assuming an exponential cutoff of the energy spectrum.

Gamma ray emission from the other two studied objects was not detected. The limits put on the pulsed and steady gamma-ray emission are currently the best available and constrain theoretical predictions.

In the technical part, it is reported about the development and fundamental studies of a new semiconductor photon detector for single photon detection. Due to its simple production, simple operation and low production costs this photon detector has the potential to revolutionize the detection of single photons. An explanation of the detector principle is given and the design and evaluation of test structures are described. The results are discussed in conjunction with the application of these sensors in future astroparticle experiments.