6 research outputs found
Three dimensional photograph of single electron tracks through a scintillator
The reconstruction of particle trajectories makes it possible to distinguish
between different types of charged particles. In high-energy physics, where
trajectories are rather long, large size trackers must be used to achieve
sufficient position resolution. However, in low-background experiments tracks
are rather short and three dimensional trajectories could only be resolved in
time-projection chambers so far. For detectors of large volume and therefore
large drift distances, which are inevitable for low-background experiments,
this technique is limited by diffusion of charge carriers. In this work we
present a "proof-of-principle" experiment for a new method for the three
dimensional tracking of charged particles by scintillation light: We used a
setup consisting of a scintillator, mirrors, lenses and a novel imaging device
(the hybrid photo detector) in order to image two projections of electron
tracks through the scintillator. We took data at the T-24 beam-line at DESY
with relativistic electrons with a kinetic energy of 5 GeV and from this data
successfully reconstructed their three dimensional propagetion path in the
scintillator. With our setup we achieved a position resolution of about 28 mum
in the best case.Comment: 9 pages, 13 figures, 1 tabl
Detection of non-classical space-time correlations with a novel type of single-photon camera
During the last decades, multi-pixel detectors have been developed capable of
registering single photons. The newly developed Hybrid Photon Detector camera
has a remarkable property that it has not only spatial but also temporal
resolution. In this work, we use this device for the detection of non-classical
light from spontaneous parametric down-conversion and use two-photon
correlations for the absolute calibration of its quantum efficiency
Fabrication of advanced LTCC structures for microwave devices
Abstract
The main objective of this thesis was to research the integration of novel materials and fabrication processes into Low Temperature Co-fired Ceramic (LTCC) technology; enabling fabrication of Radio Frequency (RF) and microwave components with advanced performance. The research focuses on two specific integration cases, which divide the thesis into two sections: the integration of tunable dielectric structures and the integration of air filled waveguides.
The first section of the thesis describes the development and characterization of low sintering temperature Barium Strontium Titanate (BST) thick film paste. Sintering temperature of BST is decreased from approximately 1350 °C down to 900 °C by lithium doping and pre-reaction of the doped composition. This allows the co-sintering of the developed BST paste with commercial LTCC materials. Additionally two integration techniques to embed tunable components in an LTCC substrate using the developed BST paste are also presented and the electrical performance of the components is evaluated. The highest measured tunability value was 44% with a bias field of 5.7 V/”m. The permittivity of the films varied between 790 and 190, and the loss tangent varied between 0.004 and 0.005, all measured unbiased at 10 kHz. The developed LTCC compatible BST paste and the presented integration techniques for tunable components have not been previously published.
In the second section of the thesis, a fabrication method for the LTCC integrated air-filled rectangular waveguides with solid metallic walls is presented. The fabrication method is described in detail and implemented in a set of waveguides used for characterization. A total loss of 0.1â0.2 dB/mm was measured over a frequency band of 140â200 GHz. The electrical performance of the waveguides is evaluated and their use demonstrated in an integrated LTCC antenna operating at 160 GHz