INDIUM MODULES Kate Sexton University of Glasgow 25092014

INDIUM MODULES Kate Sexton University of Glasgow 25/09/2014

INDIUM MODULES Developed and bonded by John Lipp, RAL Indium 1 – First characterised in March 2014 14 -07 -24_S 2 – 20 kg Bond Force (Live FE-I 4 MPI Guard IBL Ganged Pixels) 14 -07 -25_S 4 – 5 kg Bond Force (Live FE-I 4 RD 50 Guard IBL Ganged Pixels) All modules successfully tuned to and operated at 3000 e threshold, 10 To. T @ 16 ke for the purpose of these tests 1

INDIUM 1 Operated at 100 V Sr 90 and Am 241 source scans performed Threshold scans at 0 V and 100 V performed Investigated § Sigma plots with and without bias § Occupancy plots and spectra for 2 sources § Match bad pixels on both occupancy plots 2

SIGMA PLOTS 0 V & 100 V Cuts ascertained by looking 3σ either side of unbonded mean peak and counting pixels in this range Note: found that for these modules, bonded bulk noise peak is much closer to the unbonded peak which can make separation difficult and affect accuracy. Unbonded pixels primarily in lower left hand side of device 127 unbonded pixels, 13 dead pixels 3

SIGMA PLOTS 0 V & 100 V 4

SOURCE SCANS Low occupancy cuts ascertained by looking at occupancy spectra for Source Scans Sr 90 Low Occ cut: < 6000 Sr 90 High Occ cut: > 12500 Am 241 Low Occ cut: < 150 Sr 90: 171 Low Occupancy Pixels Am 241: 169 Low Occupancy Pixels § Do these match? 5

SOURCE SCANS 6

COMPARING SOURCE SCANS Look at low occupancy pixels in both source scans and match pixels § Am 241 had 169 low occ § Sr 90 had 171 low occ Good agreement 7

SR 90 SOURCE SCAN Look at sigma plots corresponding to high and low occupancy pixels Low occupancy pixels tend to correspond to unbonded channels 8

HIGH OCCUPANCY PIXELS In an effort to investigate potential merged bumps, plot map of high occupancy pixels and the directly neighbouring pixels in the rows above and below Interesting feature of pixels with high occupancy § Regularly find high occupancy pixels grouped together or § High occupancy pixels adjacent to pixels with zero or low occupancy § This may suggest the signal from 2 pixels is being read out by one 9

HIGH OCCUPANCY PIXELS Zoomed in on high occupancy regions: 10

14 -07 -24_S 2 Operated at 40 V Sr 90 and Am 241 source scans performed Threshold scans at 0 V and 100 V performed Investigated § § Sigma plots with and without bias Occupancy plots and spectra for 2 sources Match bad pixels on both occupancy plots Match high occupancy pixels on both source plots 11

SIGMA PLOTS 0 V & 40 V Unbonded pixels primarily along left hand side of device 4603 unbonded pixels, 6 dead pixels 12

SIGMA PLOTS 0 V & 40 V 13

SOURCE SCANS Low occupancy cuts ascertained by looking at occupancy spectra for Source Scans Sr 90 Low Occ cut: < 4850 Sr 90 High Occ cut: > 28000 Am 241 Low Occ cut: < 110 Sr 90: 4859 Low Occupancy Pixels Am 241: 4773 Low Occupancy Pixels § Do these match? 14

SOURCE SCANS 15

COMPARING SOURCE SCANS Look at low occupancy pixels in both source scans and match pixels § Am 241 had low 4773 occ § Sr 90 had low 4859 occ 4743 pixels appear in both maps 16

HIGH OCCUPANCY PIXELS Look at high occupancy pixels in both source scans and match pixels 11 pixels appear in both maps 17

HIGH OCCUPANCY PIXELS Again, see pattern of high/low occupancy pixels Red pixel here has occupancy value of 12338 Dark/light blue in range 13274 18

FURTHER ANALYSIS Look at cluster To. T for Am 241 source scans and compare to expectations § From Am 241, we get 60 ke. V gamma-ray peak § 60000 e/3. 6=16667 e § Modules are tuned to 10 To. T at 16 ke § Expect To. T ~ 10. 5? 19