Mapper Alignment Study of 2 Tesla Data Magnetic Field Meeting at CERN Oct. 19, 2006
This study at the Helsinki Institute of Physics outlines the assessment of mapper alignment and correction methods for 2 Tesla data, focusing on tilt effects on arms and probes relative to the magnetic field. Comparison with Tosca software, correction formulas, and results at various radial distances are discussed.
Mapper Alignment Study of 2 Tesla Data Magnetic Field Meeting at CERN Oct. 19, 2006
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Presentation Transcript
Field studies for 2 Tesla data Magnetic field meeting, CERN Oct 19, 2006 V. Karimäki Helsinki Institute of Physics
Outline • study of Mapper alignment • simple alignment correction • comparison with Tosca • summary 2
Mapper arms and probes tilt effects Tilt of arms from the plane normal to B: • causes Br and Bphi coupling to Bz • since Bz is large ans Br and Bphi are small, even small tilt causes large relative effect to Br/Bphi • the effect is sinusoidial as a function arms rotation Tilt of probes with respect to the arm: • causes a constant coupling to Bz (independent of phi) 3
Correction formulas Br -> Br + [(ai + bj sin(f-fj)]Bz Bphi -> Bphi + [(am + bn sin(f-fn)]Bz - f is arm turning angle - a's are probe dependent - b's and f's are arm dependent 4
Br vs phi at z=0 No alignment correction Mapper alignment correction 5
Bphi vs phi at z=0 No alignment correction Mapper alignment correction 6
Summary • 2 Tesla field studied • comparison with Tosca • study of Mapper alignment correction in the plane z=0 • of the order 1 mrad corrections • fairly good agreement with Tosca • Bz scale difference about 1.0075 • maps with higher current next 12