Author/Authors :
Mihovilovi?، نويسنده , , M. and ?irca، نويسنده , , S. and Allada، نويسنده , , K. and Anderson، نويسنده , , B.D. and Annand، نويسنده , , J.R.M. and Averett، نويسنده , , T. and Camsonne، نويسنده , , A. and Chan، نويسنده , , R.W. and Chen، نويسنده , , J.-P. and Chirapatpimol، نويسنده , , K. and de Jager، نويسنده , , C.W. and Gilad، نويسنده , , S. and Hamilton، نويسنده , , D.J. and Hansen، نويسنده , , J.-O. and Higinbotham، نويسنده ,
Abstract :
The techniques for the optical calibration of Jefferson Labʹs large-acceptance magnetic hadron spectrometer, BigBite, have been examined. The most consistent and stable results were obtained using a method based on singular value decomposition. In spite of the complexity of the optics, the particlesʹ positions and momenta at the target have been precisely reconstructed from the coordinates measured in the detectors by means of a single back-tracing matrix. The technique is applicable to any similar magnetic spectrometer and any particle type. For 0.55 GeV/c protons, we have established a vertex resolution of 1.2 cm, angular resolutions of 7 mrad and 13 mrad (in-plane and out-of-plane, respectively), and a relative momentum resolution of 1.6%.
Keywords :
Optical calibration , BigBite , Magnetic spectrometers , Track reconstruction
