Reconstruction in the Near Detector

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The NEAR detector shape is an elongated octagon, 3 x 8 m high and 4.8 m wide. This design requires much less steel than a regular octagon with the same scintillator coverage.The coil hole is placed off center horizontally and the detector is positioned so that the central part of the beam is 1 m away from the hole. .The detector consists of 280 interleaved planes of 4 cm wide scintillator strips and 2.54 cm thick steel planes. All scintillator strips are read out only from one end and they are oriented in the U and V direction in successive planes.

The Near Detector is divided into  four different regions :

• The VETO part, which is the most upstream part. It is 0.5 m thick and consists of 20 planes. Its information is used to reject background events whose tracks could interfere  with the actual neutrino events.
• The Target part, which consists of 40 planes (total thickness 1.0 m) and whose interactions are going to be used for all the near – far comparisons.
• The Hadron Shower part, which consists of 60 planes (total thickness 1.5 m) and its purpose is to contain the showers from neutrino interactions in the Target region.
  
• The Spectrometer part, which consists of the remaining 160 steel planes with 1 every four being instrumented with a scintillator plane.  The purpose of the spectrometer region is to measure the muon momentum.  In this region there exist an electrical 4 x plexing readout scheme for the scintillator strips.

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I have started working on Event Reconstruction, and in particular Track Reconstruction in the Near Detector.  Due to the plexing scheme in the spectrometer region  there exist multiple track solutions. I am modifying  the offline MINOS code in order to reconstruct the neutrino event tracks from the neutrino vertex to the downstream spectrometer part.

• Track Reconstruction in the Near Detector (presentation at the October 2003 reconstruction meeting)

• Status report on track reconstruction in the Near Detector ( November 2003 reconstruction meeting)

• Updated report on track reconstruction in the Near Detector ( January 2004 reconstruction meeting)
  

• Status report on ND track reconstruction ( 13 February 2004 reconstruction meeting)
  

• Progress report on ND tracking ( 26 February 2004 reconstruction meeting)

• Status report and update of ND tracking (10 March 2004 reconstruction meeting)

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 The following presentation, that I gave in the March 2004 Collaboration meeting, is a summary of the :

        - ND Tracking improvements and status

      - NEAR - FAR comparison as far as track finding and fitting are concerned.

• Status of the ND track reconstruction and ND- FD comparison.

• APS TALK

• Update on ND tracking (22 April 2004)

• Improvement of track reconstruction efficiency at lower energies (20 May 2004)

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