silicon sensors for lumical two possible options wojciech wierba institute of nuclear physics pan...
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Silicon sensors for LumiCalTwo possible options
Wojciech WierbaInstitute of Nuclear Physics PAN
Cracow
Pads•12 sectors in (15°)
•15 cylinders in r (width 13.33 mm)
•180 pads on half plane
•Inner pad - ~302 mm2
•Outer pad - ~955 mm2
•Capacitance ratio = ~3.16
Odd and even planes rotated by 7.5 deg
Strips•64 concentric strips (width 3.125 mm)
•60 radial strips (3°)
•Inner concentric strip - ~800 mm2
•Outer concentric strip - ~2734 mm2
•Capacitance ratio = ~3.42
•Radial strips - ~1885 mm2
Wafer size
• Small wafers are not suitable, causes a lot of tiles per half plane
• Best wafer size – 24 inch – not available
• 12 inch wafer acceptable (~300 mm dia)
Tiles of the sensors for both options (12” wafer)
Gap between tungsten platesHalf plane of the detector will consist 3 tiles
•Support to glue tiles and place for the electronics
•Ceramic plate ~0.5 mm thick
•Silicon sensor ~0.3 mm thick
The gap between tungsten plates should be in order of 1 mm
Comparison of the two optionsPads Strips
Masks 1 2
Number of channels 10800 7560
Energy resolution 40% E 31 – 43 % E
Angular resolution ~ 70 - 90 rad ~ 50 – 90 rad
Capacitance ratio on tile 3.16 3.42
Mean area of pad/strip 630 mm2 898 mm2
Smalest pad/strip 302 mm2 267 mm2
Largest pad/strip 955 mm2 1885 mm2
Capacitance ratio 3.16 7.06
Bias, coupling to amplifiers complicated easier
Number of sensors per tile 60 20 radial, 64 conc.
More realistic MC
•Rotation of the odd and even planes
•Angle: pads – 7.5°, strips - 7.5° ?
•Gaps between tiles (~0.1 – 0.2 mm to be discussed)
•Pads edges, guard rings
•Concentric stripes divided in 3 parts for half plane
•Gap between tungsten plates ~0.8 – 1.0 mm
Conclusions
•Both options are comparable•Number of channels is near the same•Resolutions (energy & angular) are near the same•Strips needs 2 masks•Strips needs probably 2 types of amplifiers•Pads have more complicated bias and coupling connections