compass trigger system hodoscopes
DESCRIPTION
COMPASS Trigger System Hodoscopes . Kat Ziegler, Purdue University Supervisor: Nick du Fresne von Hohenesche , University of Mainz COMPASS images: courtesy of Jens Barth, University of Bonn. 12 août 2010. CO mmon M uon and P roton A pparatus for S tructure and S pectroscopy. - PowerPoint PPT PresentationTRANSCRIPT
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COMPASS Trigger System Hodoscopes
Kat Ziegler, Purdue UniversitySupervisor: Nick du Fresne von Hohenesche, University of MainzCOMPASS images: courtesy of Jens Barth, University of Bonn
12 août 2010
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COmmon
Muon and
Proton
Apparatus for
Structure and
Spectroscopy
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COMPASS is located in Prévessin.
It started taking technical run data in 2001.
We hope to discover the spin structure of nucleons.
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Components of COMPASS* Large angle & small angle spectrometers
* Muon or hadron beam
* Polarized fixed target
* Tracking detectors
* Ring imaging Cherenkov
* Electron & hadron calorimeters
* Hodoscopes
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HodoscopesComponents
* Scintillators
* Light guides
* Magnetic shielding
* Photomultiplier tubes
* High voltage dividers
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Hodoscope Magnetic ShieldingComponents
* Soft iron core
* A little electrical tape
* Kapton insulation layer
* Mu-metal
* Another Kapton insulation layer
* Photomultiplier tube
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Hodoscope Magnetic ShieldingTasks
* Cut squares of Kapton
* Wrapped mu-metal inside and out
* Slid “scrolls” inside soft iron cores
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Hodoscope FAQQuestions
* What?Hodoscopes create a trigger signal. . .
* When?Within a 500 ns window of detecting a relevant physics event. . .
* How?By looking for coincidences (particles, whose trajectories can be retraced to the target via comparing the positions where they hit H1 and H2). . .
* Why?To reduce the amount of data that needs to be stored.
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Polarized Target* Ammonia or lithium deuteride
* 60 mK
Transverse Polarization Longitudinal Polarization
* 3 cylindrical cells (D=3 cm ) * 2 cylindrical cells (D=3 cm )
* or * or
* 30 cm/60 cm/30 cm * 60 cm/60 cm
* 10 cm spacing * 10 cm spacing
There are 3 cells so the average acceptance is the same for and .
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Primary Vertices with Target Cuts 2007
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Primary Vertices with Target Cuts 2010
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Primary Vertices with Target Cuts 2007
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Primary Vertices with Target Cuts 2010
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Hodoscope 1 (H1)
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Extrapolated Tracks to H1 2007
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Extrapolated Tracks to H1 2010
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Hodoscope 2 (H2)
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Extrapolated Tracks to H2 2007
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Extrapolated Tracks to H2 2010
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Summary of My Project* Became acquainted with C++, ROOT, and PHAST
* Tested photomultiplier tubes and high voltage dividers
* Connected photomultiplier tube signal cables
* Tuned high voltage levels and signal thresholds
* Assembled and installed magnetic shielding
* Made cuts to plot only primary vertices located in the target cells
* Extrapolated particle trajectories to hodoscope planes
* Compared new 2010 data to 2007 data
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Adventures* Montreux
* Zürich
* Venezia
* Interlaken
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Questions?