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F.Murtas INFN-CERN-Ardent J. Alozy, E.Frojdh, S . George , M. Silari CERN. GEMPIX detectors as hadron therapy beam monitors and radioactive waste detectors. GEMPIX construction Beam monitor for H adrotherapy GEMPIX for Radioactive Waste Conclusions. Gempix Detector .
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F.MurtasINFN-CERN-Ardent J. Alozy, E.Frojdh, S. George , M. Silari CERN GEMPIX detectors as hadron therapy beam monitors and radioactive waste detectors GEMPIX construction Beam monitor for Hadrotherapy GEMPIX for Radioactive Waste Conclusions
Gempix Detector The detector has two main parts : • - The quad medipix without silicon sensors • - The triple gem detector with HV filters and connector New HV GEM board Side view Quad medipix board
Gem foils and frames A new GEM layout has been designed Active area of 28x28 mm2 The electordes path have been designed to avoid the medipix wire bonding. Produced by Rui De Oliveira. New frames were designed 10x10 cm2 to fit the holes of the Quadmedipix board 5 different thickness (from 1 to 5 mm) Wire bonding position
Assembling the GEM foils The three GEM foils are assembled on top of HV GEM board
Head on detector HVGEM Console Particles to be analysed Triple GEM Mylar window HV FITPIX Gas flux AR CO2 or AR CO2 CF4 The anode is a quadnaked without silicon sensor : The active area is 9 cm2 FITPIX Console
A small TPC Length analysed Kapton window Particles to be analysed Triple GEM Gas flux The anode is a quad medipixwithout silicon sensor: The active area is 9 cm2 The particle track is analysed with 512 pixel in length of 3 cm This detector could be used also as Tissue Equivalent Proportional Chamber The track path is equivalent to 30 microns of tissue … with 17 samples/microns
GEMPIX Detectors HV Connector Medipix DAQ box Head-on version (4 detectors) Side-on version (2 detectors )
Measurements atCNAO (Pavia - Italy)Carbon ion beam at 480 Mev/nucleon
Measurements • Beam : 480 MeV/A Carbon Ion • Measurements in air • Measurements in water phantom : • 23 different depths throughout water phantom • Each position given spot 5.108carbon ion treatment (clinical treatment intensities) • Frame length = 1ms, gas = ArCO2, gain = 750 V (~0.43 keV/TOT - Proper calibration awaits the return of the detector from CNAO RP).
GEMPIX at CNAO (Pavia) • Mylar window • Gas in/out • FitpixReadout • External HV • (HVGEM)
GEMPIXas a Beam Monitor • Counts • Other particle • Single Carbon Ion • 480 MeV/A carbon ions, 10 ms frame, ASIC in Medipix(particle counting) Mode, IKrum = 5
Beam profile • As number of hits • As energy released • The overall beam shape is clearly visible
Gempix Linearity Number of counts per spills Time (s)
Bragg Peak finder at CNAO Phantom used at CNAO Stepper Motor Gempix Thin Window Several measurement of energy deposition along the beam (5x108 Carbon ions per 10 spills)
Depth profile and beam dimension Spot width here is sigma of gaussian (FWHM = 2.3 sigma) Energy deposition is ~0.43 keV/TOT
Energy deposition: 3D reconstruction Linear Log 3D reconstruction This part (neutrons and gammas) could be analyzed with really high resolution
Single Event Upset • SEU Events • Depth = 124 mm (in braggpeak), ~0.43 keV/Count • (9.6 MHz, TOT mode), IKrum = 1, 1ms frame
Reconfiguring • Reset every frame • Reset/10frames • Reset at start • No CfgResets
Sample Preparation Fraiseuse DECKEL FP4M for powder production reducing the 60CO background Boxes supplied by SMIPA s.r.l Dimension: 38x38x4 mm3 (now 38x38x8 mm3) Weight: 3.951 ± 0.15% Measurements for Fe-55 concentration with GEMPIX , two different configuration : Drift gap 11 mm Drift gap 3 mm Support conceived for measurements with samples and calibration sources
Radioactive waste: 55Fe 100s counts 1 sec radioactive source
Signal vs Background X-ray candidates Gas AR CO2CF4 Gate: 1 s HV 1200 V Gas flux: 3.5 l/h Clk: 24 Ikrum: 5 Polarization: - Bck
Cluster parameters measurements Cluster type Cluster volume Inner size 55Fe 60Co 55Fe 60Co 55Fe 60Co 55Fe 60Co 55Fe 60Co Size y vs size x Size Border size
Online analysis Once that the calibration values are set in the Python script, an online analysis can be performed Number of big blob Cut on size Cut on charge Number of X-Rays measured in 1000 sec
Drift 3 mm vs drift 11 mm Attenuation length 2.91 cm Theory: 11 mm/ 3 mm = 2.6 Measurements: 11 mm/ 3 mm = 2.7 Waiting the measurements from certificated company for the final calibration
Summary • Six GEMpix detectors have been built and they show good performances • from single particle detections to high intensity beam monitor • Really good cluster analysis is possible thanks to the Fitpix software pakage • Software tools and detector tuning are still needed for the cluster analysis in gas (dE/dX, particle id, 3D track reconstruction....) • The detector could be easily improved with Timepix3 chips • Other applications and measurements are scheduled for next months • Monitor for burning plasma (KSTAR - PETAL) • Measurements for micro and nanodosimetry with tissue equivalent gas • Monitor for gamma radiotherapy