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Sven Vahsen

Publications and source records attributed to Sven Vahsen.

4 recordsLinked to original sources

MPGDs for TPCs at future lepton colliders

This submission will focus on advancements and advantages of Micro Pattern Gas Detector (MPGD) technologies and their applications to the construction of a dedicated Time Projection Chamber (TPC) that can serve as an excellent main tracker for any multipurpose detector that can be foreseen to operate at a future lepton collider. The first portion of the report will be the executive summary. It will be followed by sections detailing the applications of MPGDs specifically to the construction of the LCTPC for the ILD at ILC, for a possible upgrade of the Belle II detector at SuperKEKB and for the design of a TPC for a detector at CEPC. MPGD technologies offer synergies with other detector R&D and several application domains; a few examples will be provided in the context of the ongoing Snowmass long range planning exercise in the USA. Links to industrial partnership and work with institutions in the USA will be highlighted when appropriate.

physics.ins-det

A TPC-based tracking system for a future Belle II upgrade

In the next decade, intensity frontier experiments will require tracking systems that are robust against high event and background rates while maintaining excellent tracking performance. We develop a first conceptual design of a tracking system for a hypothetical future experiment--here imagined as a successor to Belle II--built around a time projection chamber (TPC) with high resolution readout. This choice necessitates a significant expansion of the silicon vertex detector as well as a new fast timing layer. We simulate the performance of such a system in the Belle II simulation framework, probe its major technical challenges, and demonstrate that such a system is suitable for projected luminosities at the next generation of intensity-frontier colliders.

physics.ins-det

A time resolved study of injection backgrounds during the first commissioning phase of SuperKEKB

We report on measurements of beam backgrounds during the first commissioning phase of the SuperKEKB collider in 2016, performed with the plastic scintillator and silicon photomultiplier-based CLAWS detector system. The sub-nanosecond time resolution and single particle detection capability of the sensors allow bunch-by-bunch measurements, enable CLAWS to perform a novel time resolved analysis of beam backgrounds, and make the system uniquely suited for the study of injection backgrounds. We present measurements of various aspects of regular beam background and injection backgrounds which include time structure and decay behavior of injection backgrounds, hit-energy spectra and overall background rates. These measurements show that the elevated background rates following an injection generally last for several milliseconds, with the majority of the background particles typically observed within the first 500 us. The injection backgrounds exhibit pronounced patterns in time, connected to betatron and synchrotron oscillations in the accelerator rings. The frequencies of these patterns are determined from detector data.

physics.ins-det

Application of Time Projection Chambers with GEMs and Pixels to WIMP Searches and Fast Neutron Detection

We present work on the detection of neutral particles via nuclear recoils in gas-filled Time Projection Chambers (TPCs). We employ Gas Electron Multipliers (GEMs) to amplify the signal and silicon pixel electronics to detect the avalanche charge. These technologies allow ionization in the target gas to be detected with low noise, improved position and time resolution, and high efficiency. We review experimental results obtained in previous years, and report on ongoing simulation studies and construction of the first prototype at the University of Hawaii. We also present prospects of using such detectors to perform direction-sensitive searches for WIMP dark matter and fast neutron from fissionable material.

physics.ins-det