The SuperNEMO Tracker, Irina Nasteva, 21 Dec 2006

The SuperNEMO tracker:

simulations and 9-cell prototype

Irina Nasteva

Manchester HEP Group Christmas meeting

21 December 2006

The SuperNEMO Tracker, Irina Nasteva, 21 Dec 2006 2

What I did last year

• Finished writing my thesis on ATLAS/FP420 in June.

• “Exclusive Higgs production and decay to WW(*) at the LHC and Semiconductor Tracker studies for the ATLAS detector”.

• Had my viva in July.

• Joined SuperNEMO unofficially in June, officially in August.

• Worked on electrostatic simulations of the SuperNEMO tracker layout and of the 9-cell prototype.

• Now testing the first 9-cell prototype.

• Maintaining SuperNEMO software at Manchester.

The SuperNEMO Tracker, Irina Nasteva, 21 Dec 2006 3

The SuperNEMO tracker will consist of drift cells in Geiger mode. We are investigating the tracker parameters like basic cell design,tracker module layout, operating parameters (gas, voltage).

Electrostatic simulations to study:

• Cell layouts-- octagonal vs hexagonal

• Vary number of cathodes per cell

• Vary wire diameters

• Comparison between two simulation programs, Garfield (IN) and FlexPDE (Steve Snow), showed they agree to within 0.4%.

• The optimal cell layout is octagonal, with 12 cathodes of diameter 50 m around a 30-m anode.

SuperNEMO tracker simulations

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The first 9-cell prototype

• 3x3 cells of 28 mm pitch• Length = 1.8 m• Wire diameter = 50 m• Gas: He, Ar (1%), ethanol at 14˚C

• Triggered on cosmics by 4 scintillators in coincidence.

• 4 anode signals are read out by 2 oscilloscopes using LabView.

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9-cell first “tracks”

• Equal voltage (1650 V) applied to all 4 cells leading to lower effective field on the middle cells.

• The efficiency of the middle cell when triggering on the top and bottom cells is 98%.

The reconstructed hit positions along the wire length agree well between the three anodes.

The SuperNEMO Tracker, Irina Nasteva, 21 Dec 2006 6

Plans for next year

• Tests of 9-cell and single-cell prototypes.

• Wire diameter studies.

• Gas studies.

• Construction of a 100-cell prototype.

• Detector simulation studies of SuperNEMO module layouts.

• Possibly a NEMO 3 physics analysis.