Progress of x-ray tests at ETH Marco Rossini Institute for Particle - PowerPoint PPT Presentation

Progress of x-ray tests at ETH Marco Rossini Institute for Particle Physics, ETH Zürich 26. March 2012 Marco Rossini (ETH) X-ray test progress 26. March 2012 1 / 11

Setup progress The x-ray setup currently consists of ◮ X-ray tube, generator, cabin ◮ Single ROC setup with temperature control (17°C) with shielded testboard ◮ Movable array of fluorescence targets ◮ Spectrometer Marco Rossini (ETH) X-ray test progress 26. March 2012 2 / 11

Single ROC setup ◮ ROC in thermal contact with cooling plate ◮ Plate cooled with peltier element, measured with Pt1000 ◮ Temperature controller establishes stable conditions ◮ Not in final state yet Marco Rossini (ETH) X-ray test progress 26. March 2012 3 / 11

Fluorescence setup ◮ Array with 7 slots for target materials ◮ Target change through motion of entire array with linear stage ◮ Construction designed for minimal parasitic fluorescence emission and for large yield ◮ Option for K β filtering (attachment not shown in picture) ◮ Targets obtained until now: Iron (Fe), Copper (Cu), Molybdenum (Mo), Silver (Ag), Tin (Sn) ◮ Target under evaluation: Barium (Ba) compound (powder) Marco Rossini (ETH) X-ray test progress 26. March 2012 4 / 11

Fluorescence spectra Spectra of all materials using current setup: Steel (Fe) Copper (Cu) Molybdenum (Mo) Silver (Ag) Tin (Sn) Barium chloride Marco Rossini (ETH) X-ray test progress 26. March 2012 5 / 11

High rate pixel map test DCol test Features: DCol hit map ROC 0 Hits ◮ Triggers at a user set frequency 14000 12000 ◮ Test duration user set 10000 ◮ Accumulated pixel hits sent to the 8000 6000 computer 4000 ◮ Pixel hits histogrammed in 2d 2000 0 and 1d 0 5 10 15 20 25 Double column ◮ Pulse height histogrammed Bump bonding test Pixel hit map 80 Row ◮ Hit multiplicity histogrammed 300 70 ◮ Time < 1 min total 60 250 50 200 40 150 Used for 30 100 20 ◮ Double column test 50 10 ◮ Bump bonding test 0 0 0 10 20 30 40 50 Column Marco Rossini (ETH) X-ray test progress 26. March 2012 6 / 11

High rate efficiency test Features ◮ Uses calibrate signal to inject each pixel N times along with x-rays ◮ Reads out hits, distinguishing pixels ◮ Compares number of read out pixels with N to compute efficiency ◮ Time ∼ 2 min (1 ROC, bandwidth limited) Pixel efficiency map module Pixel efficiency distribution ROC 0 80 100 Row Pixels 700 Entries Entries 4160 4160 90 70 Mean Mean 94.11 94.11 600 80 RMS RMS 2.664 2.664 60 Underflow Underflow 0 0 70 500 Overflow Overflow 0 0 50 60 Integral Integral 4160 4160 400 40 50 300 40 30 30 200 20 20 ∼ 96 MHz / cm 2 ∼ 96 MHz / cm 2 100 10 10 0 0 0 0 10 20 30 40 50 0 20 40 60 80 100 Column Efficiency [%] Marco Rossini (ETH) X-ray test progress 26. March 2012 7 / 11

High rate s-curve test Features ◮ Determines the s-curve for each pixel in terms of VCal by injecting the calibrate signal with varying strength ◮ Works while under x-ray radiation ◮ Time ∼ 30 min (1 ROC, bandwidth limited) ∼ 93 MHz / cm 2 ∼ 93 MHz / cm 2 Threshold (xray) Noise (xray) # Pixels # Pixels 1400 1200 Entries Entries 4089 4089 Entries Entries 4089 4089 Mean Mean 61.22 61.22 Mean Mean 4.648 4.648 1200 1.209 1.209 RMS RMS 0.6896 0.6896 RMS RMS 1000 0 0 Underflow Underflow 0 0 Underflow Underflow 1000 0 0 Overflow Overflow 2 2 Overflow Overflow 800 Integral Integral 4089 4089 Integral Integral 4087 4087 800 600 600 400 400 200 200 0 0 0 50 100 150 200 250 0 1 2 3 4 5 6 7 8 9 10 Threshold (VCal units) Noise (VCal units) Marco Rossini (ETH) X-ray test progress 26. March 2012 8 / 11

VCal calibration Using existing test: ◮ VcThr scan while under monochromatic x-rays → s-curve ◮ Set found value of VcThr ◮ Threshold map in terms of VCal for all pixels ◮ Averages over all pixels on a chip ◮ Yields VCal corresponding to x-ray energy ◮ Use multiple x-ray lines to make linear calibration Time: ◮ Takes 3 minutes per line (clock stretch 100, 30k Triggers) ◮ Yields 20k Hits above threshold (in old module test: < 1k) ◮ Can increase trigger frequency by factor of 10 (firmware change) ◮ Can live with only 2k Hits or increase time spent ◮ Can test multiple modules at once Marco Rossini (ETH) X-ray test progress 26. March 2012 9 / 11

S-curve for VCal calibration VcThr scan with monochromatic x-rays (Molybdenum fluorescence) a = 51 . 0142 ± 0 . 6055 ( 1 . 187 %) b = 2 . 37153 ± 0 . 2979 ( 12 . 56 %) c = 2754 ± 567 ( 20 . 59 %) d = 58 . 7048 ± 0 . 1589 ( 0 . 2707 %) e = 2 . 82404 ± 0 . 2015 ( 7 . 135 %) f = 297 . 546 ± 25 . 95 ( 8 . 721 %) g = 17782 ± 767 . 7 ( 4 . 318 %) h = 56 . 7872 ± 9 . 378 ( 16 . 51 %) VcThr Marco Rossini (ETH) X-ray test progress 26. March 2012 10 / 11

Summary ◮ A working setup exists for single ROCs ◮ Setup for direct and fluorescence illumination is done ◮ Many tests are implemented and working Outlook: ◮ Measure fluorescence and direct spectra (with Daniel Narrias) ◮ Measure beam profile for designing module setup (with Daniel) ◮ Understand some issues that measurements show More distant outlook: ◮ Verify tests work with full modules ◮ Design module setup ◮ Implement more tests (?) Marco Rossini (ETH) X-ray test progress 26. March 2012 11 / 11