Plots of merit:

CJC performance (cosmics '99)

• Triplet resolution vs drift length (cosmics, pt>5 GeV/c)

 
• RMS of residuals vs drift length (cosmics, pt>5 GeV/c)

 
• Track parameter resolution  vs momentum (comparing cosmic track halves, contained in Z)

CJC+CST performance repro 2000 pass 2.0 (cosmics '00)

• DCA and curvature resolution from pass 2.0 (comparing cosmic track halves, contained in Z, pt>10 GeV/c)

 

 
 
 
 
 
 
 

The upper row compares events where one track has no and the other at least one CST hits (-> CJC resolution), in the second (third) row both track must have at least 1 (2) CST hits (difference devided by sqrt(2) -> CST resolution).

The CJC shows an bias of about 0.3 sigma. This is most probably due to the fact that the CJC calibration assummed that the electric field in the chamber is contstant in time, but in reality it varies with the ionization (-> HERA e-current) in the chamber. This leads to a variation of the radial (and azimutal ?) drift velocity profile. A coarse radial correction is in preparation (for pass 2.1).

The CST shows of 0.2-0.6 sigma. This is probably due to a residual rotation (~0.1mrad) and an vertical displacement (~20mu) vs the CJC.
 

• DCA and curvature resolution with CJC recalibration (mainly radial drift velocity profile adjusted)

 
• DCA and curvature resolution with CJC and CST recalibration (mainly rotation, vert. displacement)

Software:

• Source code (car files):  /afs/desy.de/group/h1/h1rec9/cjcrec_ttf_<version>.car

 
• Library: /afs/desy.de/group/h1/h1rec9/lib/libcjcrec_ttf.a  (on Linux, SGI)

 
• CJCLOOK executable: /afs/desy.de/group/h1/look/bin/cjclook_ttf (Linux only)

(use  'CJCFIG CJCS' for cosmics to visualize residuals)

Database:

For other periods they are still not on NDB but have to be read from cards file, for the current version use:

$NDB $TEXT
* calibration data for CJCREC_TTF, 1996
   DBCARD '/h1/h1rec9/csf8_ep96_test5.car'
   DBCARD '/h1/h1rec9/csf0_ep99_test4.car'
END$