A Quartz Cherenkov Detector for Compton-Polarimetry at Future e+e- Colliders

Precision polarimetry is essential for future e+ e- colliders and requires Compton polarimeters designed for negligible statistical uncertainties. In this paper, we discuss the design and construction of a quartz Cherenkov detector for such Compton polarimeters. The detector concept has been developed with regard to the main systematic uncertainties of the polarisation measurements, namely the linearity of the detector response and detector alignment. Simulation studies presented here imply that the light yield reachable by using quartz as Cherenkov medium allows to resolve in the Cherenkov photon spectra individual peaks corresponding to different numbers of Compton electrons. The benefits of the application of a detector with such single-peak resolution to the polarisation measurement are shown for the example of the upstream polarimeters foreseen at the International Linear Collider. Results of a first testbeam campaign with a four-channel prototype confirming simulation predictions for single electrons are presented

A Calibration System for Compton Polarimetry at e+e−e^+e^- Linear Colliders

Polarimetry with permille-level precision is essential for future electron-positron linear colliders. Compton polarimeters can reach negligible statistical uncertainties within seconds of measurement time. The dominating systematic uncertainties originate from the response and alignment of the detector which records the Compton scattered electrons. The robust baseline technology for the Compton polarimeters foreseen at future linear colliders is based on an array of gas Cherenkov detectors read out by photomultipliers. In this paper, we will present a calibration method which promises to monitor nonlinearities in the response of such a detector at the level of a few permille. This method has been implemented in an LED-based calibration system which matches the existing prototype detector. The performance of this calibration system is sufficient to control the corresponding contribution to the total uncertainty on the extracted polarisation to better than $0.1\%$.Comment: 27 pages, 17 figure

Marshall University Music Department Presents a Faculty Recital, Henning Vauth, Piano

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Marshall University Music Department Presents the 2014 Birke Fine Arts Festival, Trending Now: Artists and Audiences in the Information Age, Fifth Annual Festival of New Music, Concert Five

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Spin Transport and Polarimetry in the Beam Delivery System of the International Linear Collider

Polarised electron and positron beams are key ingredients to the physics programme of future linear colliders. Due to the chiral nature of weak interactions in the Standard Model - and possibly beyond - the knowledge of the luminosity-weighted average beam polarisation at the $e^+e^-$ interaction point is of similar importance as the knowledge of the luminosity and has to be controlled to permille-level precision in order to fully exploit the physics potential. The current concept to reach this challenging goal combines measurements from Laser-Compton polarimeters before and after the interaction point with measurements at the interaction point. A key element for this enterprise is the understanding of spin-transport effects between the polarimeters and the interaction point as well as collision effects. We show that without collisions, the polarimeters can be cross-calibrated to 0.1 %, and we discuss in detail the impact of collision effects and beam parameters on the polarisation value relevant for the interpretation of the $e^+e^-$ collision data.Comment: 34 pages, 11 figure

Marshall University Music Department Presents a Concert of Soloists Competition, February 5, 2012

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Marshall University Music Department Presents a MUsic Alive Faculty & Guest Artist Collaboration Series, Freya String Quartet, Henning Vauth, piano, November 15, 2012

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Marshall University Music Department Presents a Senior Recital, Jared Layman, trombone, assisted by Dr. Henning Vauth, piano and The Hindenburg Experience

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Marshall University Music Department Presents an American Classics, Michael Stroeher, trombone, and Henning Vauth, piano

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Marshall University Music Department Presents a Faculty Duo Recital, Şőlen Dikener, cello and Henning Vauth, piano

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