80 likes | 261 Views
СС E measurements with alpha source (241Am) on the test structures. Strip-pixel test structure: 7x7 mm^2; pitch=15 mkm; Y=8 strips; X=7 strips. Set up: - all 8 Y-strip and 7 X-strip shorted US-bonding and connected with two pins (Y-pin and X-pin);
E N D
ССE measurements with alpha source (241Am) on the test structures • Strip-pixel test structure: 7x7 mm^2; pitch=15 mkm; Y=8 strips; X=7 strips. • Set up: - all 8 Y-strip and 7 X-strip shorted US-bonding and connected with two pins (Y-pin and X-pin); - n+ Ohmic contact glued with Ag-glue on the Au-layer ceramics PCB; - CS-Amplifier connected with: 1. Y+X; 2. Y; 3. X. N.Zamyatin, JINR, 20-21 Oct., Prague
Test structures: two strip-pixel 15mkm (#1-1; #2-1) and two PADs N.Zamyatin, JINR, 20-21 Oct., Prague
Alpha spectrum (241Am) for test-PAD at bias 50 V, alpha source without collimator (putted on the p+ contact) N.Zamyatin, JINR, 20-21 Oct., Prague
Alpha spectrum (241Am) for test#2-1_strip-pixel at bias 50 V, all Y- and X- strips connected together, alpha source without collimator (putted on the p+ contact). Max spectra=2912 ch, it’s correspond 100% CCE N.Zamyatin, JINR, 20-21 Oct., Prague
Y-alpha spectrum (241Am) for all 8 Y-strips test#2-1 at bias 50 V, all 7 X-strips connected with the equal Y-strips RC-value (C=Cdinamic/PAmp), alpha source without collimator (putted on the p+ contact.- Edge of the max Y-spectra shifted on the left from 100%, because X-part of the signals collected on X-strips.- This spectra indicated, that all time should be signals (on Y- or on X- strips) with small amplitudes, that is problem of Signal/Noise!!! N.Zamyatin, JINR, 20-21 Oct., Prague
X-alpha spectrum (241Am) for all 7 X-strips test#2-1 at bias 50 V, all 8 X-strips connected with the equal X-strips RC-value (C=Cdinamic/PAmp), alpha source without collimator (putted on the p+ contact.- Edge of the max X-spectra shifted on the left, because Y-part of the signals collected on Y-strips.- Note: X-strips more noisly N.Zamyatin, JINR, 20-21 Oct., Prague
Y-alpha spectrum (241Am) for all 8 Y-strips test#2-1 at bias 50 V, all 7 X-strips are “floating”, alpha source without collimator (putted on the p+ contact.- Edge of the max Y-spectra have two pick, this effect connected with floating X-strips and interstrip capacitance “cross talk Y-X” N.Zamyatin, JINR, 20-21 Oct., Prague
Conclusions : • Measurements of the alpha spectra for the strip-pixel sensors is very easy and informative method for the study of the Charge Collection on X- and Y- strips; • Preliminary results on the 15 mkm Strip-Pixel structures indicated about big amplitudes range of the Y- and X-signals (signal Y and X not 50% from total alpha pick). For the events with big Y(or X)-amplitudes we have small X(or Y)-signals and correspond low S/N, that is problem of the 100% efficiency on both Y- and X- coordinate; • For the ideal topology of the Strip-Pixel sensors should be the ratio Qy or Qx/Qy+Qx=0.5; • What to do?: - increase thickness up to 0.6mm; decrease pitch (?) or ZIP-shape (?); come back to SS-strip sensors. N.Zamyatin, JINR, 20-21 Oct., Prague