1. F.Murtas G.Claps, E.Baracchini 1 EDIT FrascatiOctober 22 h 2015 GEMPIX detectors : GEM with higly pixelated readout Introduction GEMPIX Detectors GEMPIX Applications Measurements: gain and drift velocity F.Murtas, G.Claps, E. Baracchini Laboratori Nazionali Frascati - INFN A.Balla, G.Claps, G.Corradi, G.Croci, E.Baracchini, D.Tagnani, D.Pacella A.Balla, G.Claps, G.Corradi, G.Croci, E.Baracchini, D.Tagnani, D.Pacella

2. F.Murtas G.Claps, E.Baracchini 2 EDIT FrascatiOctober 22 h 2015 A triple GEM Chamber GEM foil 70 µm140 µm A Gas Electron Multiplier (F.Sauli, NIM A386 531) is made by 50  m thick kapton foil, copper clad on each side and perforated by an high surface-density of bi-conical channels; Several triple GEM chambers have been built in Frascati in the LHCb Muon Chamber framework* Working with different levels of gain it is possible to obtain high level of gamma- neutron discrimination

3. F.Murtas G.Claps, E.Baracchini 3 EDIT FrascatiOctober 22 h 2015 Main Characteristics The main characteristics are : - Extended dynamic range (from single particle up to 10 8 partcles cm -2 s -1 ) - Good time resolution (5 ns) - Good spatial resolution (200  m) - Radiation hardness (2C/cm 2 ) Thanks to these characteristics a GEM detector can be used for: - plasma imaging for fusion reactors (tokamak) neutron and X rays, - diagnostics for beam particles (high energy physics, hadron therapy) - detectors for fast and thermal neutrons, - medical applications (diagnostics and therapy): - medical diagnostics medicale in gamma therapy; - medical diagnostics in hadro therapy; - steress diagnostics in industrial applications; - environment monitoring; - radioactive waste imaging;

4. F.Murtas G.Claps, E.Baracchini 4 EDIT FrascatiOctober 22 h 2015 GEMpix Assembling Quad medipix board The detector has two main parts : - The quad medipix with a naked devices - The triple gem detector with HV filters and connector New HV GEM board Top view M.Campbell, J.Alzoy 2.8 cm

5. F.Murtas G.Claps, E.Baracchini 5 EDIT FrascatiOctober 22 h 2015 Head on detector Gas flux AR CO 2 The detector is a quad naked medipixes (no silicon sensor): The active area is 9 cm 2 Triple GEM Mylar window Particles to be analysed 3 mm ionization gap This type of device can be used for high flux of X rays Gain tuneable from 1 up to 10 4 Time resolution: 5 ns Energy sensitivity few keV

6. F.Murtas G.Claps, E.Baracchini 6 EDIT FrascatiOctober 22 h 2015 Side on detector Gas flux The detector is a quad naked medipix : The active area is 9 cm 2 The particle track is analysed with 512 pixel in 3 cm length The longest drift gap used up to now is 5 cm. Triple GEM Kapton window Particles to be analysed Length analysed

7. F.Murtas G.Claps, E.Baracchini 7 EDIT FrascatiOctober 22 h 2015 GEMPIX readout TOA Wilkinson ADC

8. F.Murtas G.Claps, E.Baracchini 8 EDIT FrascatiOctober 22 h 2015 GEMPIX detectors and HV https://web2.infn.it/GEMINI/ HVGEM Side-on (2 cm drift) Head-on TPC (5 cm drift)

9. F.Murtas G.Claps, E.Baracchini 9 EDIT FrascatiOctober 22 h 2015 GEMPIX applications Gempix Detector (10cm 2 GEM detector read by 55x55  m pixels, 262 000 channels ) - radioactive CERN waste 55Fe measurements (LEP, SPS, etc) - 3D measurements of energy released in water phantom in hadrotherapy treatment facility (CNAO Pavia) - Gamma ray monitor for radiotherapy dose measurement (Polic.Tor Vergata Rome) - X ray monitor in Inertial Fusion test facility (Petal, France ) - X ray monitor in KSTAR Tokamak reactor (Korea) - Proton tomography prototypes (Nikef, Nederland) - Dark matter prototype for Directional dark mattersearches with carbon nanotubes - Dark matter prototype for NITEC: a Negative Ion Time Expansion Chamber for directional Dark Matter search Hadrotherapy Radiotherapy: GEMPIX vs radiochromic film 3D reconstruction

10. F.Murtas G.Claps, E.Baracchini 10 EDIT FrascatiOctober 22 h 2015 GEMPIX for Fusion Laser Produced Plasmas (ABC, ENEA) Tokamak Plasmas (KSTAR, South Korea) A frame every 700 ms Laser pulse duration = 3 ns Wavelenght = 1054 nm A maximum energy of 100 J per pulse

11. F.Murtas G.Claps, E.Baracchini 11 EDIT FrascatiOctober 22 h 2015 GEMpix detector and EBT gafcromic comparison through γ test: the bi-GEM configuration 8x8 mm 2 irradiating field 6 MV γ < 1, 97.57 % 6 MV γ < 1, 90.50 % 6 MV γ < 1, 87.04 % Multileaf collimator

12. F.Murtas G.Claps, E.Baracchini 12 EDIT FrascatiOctober 22 h 2015 Phantom used at CNAO Bragg Peak finder at CNAO Thin Window Gempix Stepper Motor Several measurement of energy deposition along the beam (5x10 8 Carbon ions per 10 spills)

13. F.Murtas G.Claps, E.Baracchini 13 EDIT FrascatiOctober 22 h 2015 3D reconstruction Energy deposition in hadrotherapy

14. F.Murtas G.Claps, E.Baracchini 14 EDIT FrascatiOctober 22 h 2015 GEMPIX for radioctive waste X-ray candidates Bkg GEMPIX 1 hour of data acquisition Medipix 10 hours of data acquisition External companies : days Very good pattern recognition and particle identification Correlation between GEMPIX and Medipix Data acquired in one second

15. F.Murtas G.Claps, E.Baracchini 15 EDIT FrascatiOctober 22 h 2015 GEMPIX as Negative Ion TPC for directional Dark Matter searches J. Martoff et al., NIM A 440 355 < 0.5 mm diffusion achieved over 50 cm drift length w.r.t. 10 mm obtained with electrons (no magnetic field) --Larger allowed drift length thanks to negative ion suppressed diffusion --3D track reconstruction and head-tail discrimination capability thanks to time & charge GEMPIX measurements --Improved position and energy resolution thanks to possibility of single ionization cluster measurement Cluster structure clearly visible

16. F.Murtas G.Claps, E.Baracchini 16 EDIT FrascatiOctober 22 h 2015 Measurements at EDIT 2015 Cosmic Rays in TOT mode cluster analysis Gain measurements with 55Fe source Drift Velocity Measurements with the BTF eleectron Beam pixelman FITPIX DAQ interfac FITPIX DAQ interfac HVGEM GEMPIX Online display Online plots HV Control

17. F.Murtas G.Claps, E.Baracchini 17 EDIT FrascatiOctober 22 h 2015 The GEMPIX TPC 70 counts 7 us... 5 cm 3D reconstruction

18. F.Murtas G.Claps, E.Baracchini 18 EDIT FrascatiOctober 22 h 2015 X Ray Source spectrum 4 points at 1300, 1260, 1220, 1180 V 55 Fe HV Value Mean charge G eff = A e α(Vgem1+Vgem2+Vgem3) A and α depend on the gas mixture.

19. F.Murtas G.Claps, E.Baracchini 19 EDIT FrascatiOctober 22 h 2015 Online measurements Start with trigger end 10 us Single frame of 3 usBeam

20. F.Murtas G.Claps, E.Baracchini 20 EDIT FrascatiOctober 22 h 2015 Drift velocity measurement X projection Y projection Z projection Z position Drift Time