A compact TPC for high intensity beam tracking

A compact TPC for high intensity beam tracking system at H 8 G. Corradi, F. Murtas, M. Pistilli, D. Tagnani Laboratori Nazionali di Frascati INFN P. Valente Sezione Roma INFN Triple GEM detector principia l Monitors for Crystal experiment at SPS l A compact Time Projection chamber with GEM l F. Murtas CERN 10 -Nov-2009 1

A triple GEM Chamber A Gas Electron Multiplier (F. Sauli, NIM A 386 531) is made by 50 m thick kapton foil, copper clad on each side and perforated by an high surface-density of bi-conical channels; 70 µm 140 µm Head on particle impinging a GEM chamber GEM foil * M. Alfonsi et al. , The Triple-GEM detector for the M 1 R 1 muon station at LHCb, N 14 -182, 2005 IEEE NSS Conference, Puerto Rico F. Murtas CERN 10 -Nov-2009 2

A Standard Triple GEM construction The detectors described in this talk are built starting form the standard 10 x 10 cm 2 : only one GEM foil has been modified to have central electrodes. 128 pads 6 x 12 mm 2 G 3 G 2 G 1 The GEM are stretched and a G 10 frame is glued on top F. Murtas The frame for the G 3 foil has been modified for the gas inlet CERN 10 -Nov-2009 3

The FEE board used The card is based on *Carioca Chip and has been designed and realized in Frascati by Gianni Corradi ; Total dimension : 3 x 6 cm 2 16 channels for each card: channel density of 1 ch/cm 2 Sensitivity of 2 -3 f. C; LVDS output (25 ns); Radhard; Extremely modular and usable for GEM applications All the anode PCB have been designed with the same connector layout for a total of 128 channels * Development of the CARIOCA front-end chip for the LHCb muon detector. W. Bonivento, et al NIM A 491: 233 -243, 2002 F. Murtas CERN 10 -Nov-2009 4

The mother board On this mother board HV and LV ground are connected each other through a 10 KW resistor CARIOCA readout electronics m. V Signals path HV filters Threshold calibration HV in 6 m. V/f. C F. Murtas Threshold & LV in CERN 10 -Nov-2009 4 32 LVDS signals out 5

The GEM monitors at UA 9 F. Murtas CERN 10 -Nov-2009 6

Installation on Crystal Tank at SPS GEM monitors Proton beam (200 Ge. V) Bending Crystal SPS tunnel Proton beam pipe F. Murtas CERN 10 -Nov-2009 7

Beam monitor at BTF Frascati Beam profile at BTF in two configuration : narrow and wide beam 10 cm F. Murtas CERN 10 -Nov-2009 8

Channeling seen by GEMs at UA 9 Crystal Angular Scan MD on August 11 th Channeled Beam seen by Medipix 2 Decrease of beam halo scattering, due to channeling GEM 2 2 KHz signals perfectly correlated with scintillators GEM 1 rate is 20 Hz (as expected being upstream of the crystal) F. Murtas CERN 10 -Nov-2009 9

The GEM TPC F. Murtas CERN 10 -Nov-2009 10

TPG for beam diagnostic It’s essentially a small TPC with a 4 cm drift and readout with triple GEM In this way also high current beam can be monitored in position box cross section Particle beam Triple GEM structure Without magnetic field FEE electronics The material budget crossed by a particle is only two kapton foils (<0. 2%X 0) used for the field cage necessary for the drift field uniformity 14 strips with 15 resistors (10 MW) for a total field cage current of 1 A F. Murtas CERN 10 -Nov-2009 11

Assembling the TPG chamber (M. Pistilli) F. Murtas CERN 10 -Nov-2009 5 cm 12

Cosmic rays in free running 5 cm 5 cm A gate of 8 ms is open randomly without an external trigger Threshold set at about 7 f. C Gas mixture Ar CO 2 (70 -30) Triple GEM Gain at about 104 F. Murtas For this type of monitor a new layout has been designed for an active volume of 5 x 5 x 4 cm 3 Pad dimension 3 x 6 mm 2 Threshold set at 7 f. C Gas mixture Ar CO 2 (70 -30) Triple GEM Gain at about 104 Sub-millimetric precision CERN 10 -Nov-2009 13

Some other cosmic rays F. Murtas CERN 10 -Nov-2009 14

Test at BTF frascati F. Murtas CERN 10 -Nov-2009 15

Online single event at Test Beam One electron in 10 ns (trigger from linac) Top view Side view Front view Lateral view History view F. Murtas CERN 10 -Nov-2009 16

Online single event at Test Beam One electron in 10 ns Top view Side view Front view Lateral view History view F. Murtas CERN 10 -Nov-2009 17

Online single event at BTF Two electrons in 10 ns Top view Side view Front view Lateral view History view F. Murtas CERN 10 -Nov-2009 18

Online single event at BTF Two electrons in 10 ns Top view Side view Front view Lateral view History view F. Murtas CERN 10 -Nov-2009 19

High Intensity 250 electrons (in 10 ns) Top view Side view z distrib. # hits History view F. Murtas CERN 10 -Nov-2009 20

High Intensity 1400 electrons (in 10 ns) Top view Side view z distrib. # hits History view F. Murtas CERN 10 -Nov-2009 21

High Intensity 4400 electrons (in 10 ns) Top view Side view z distrib. # hits History view F. Murtas CERN 10 -Nov-2009 22

Test at H 8 F. Murtas CERN 10 -Nov-2009 23

Test beam setup Medipix array 8 columns 16 rows particles TPG chamber Electron drift F. Murtas CERN 10 -Nov-2009 24

Single event at H 8 Side view Front view History view Top view particles F. Murtas CERN 10 -Nov-2009 25

Residuals (events with >2 hits) Residual measured by each pad mm 8 pads Z 0 mm Y coordinate (mm) residual 100 mm mm Y coordinate (mm) 50 mm in track position resolution F. Murtas CERN 10 -Nov-2009 26

Chamber calibration 11. 31 mm 21. 34 mm Beam position with a chamber displacement of 1 cm Electron drift (mm) 11. 43 mm 21. 17 mm mm F. Murtas CERN 10 -Nov-2009 27

Channeling at H 8 mm front view # pad Channeled beam mm # pad top view # pad Time(nevt) F. Murtas CERN 10 -Nov-2009 28

Traking system at H 8 A tracking system with 50 micron resolution on both views using four TPCs (two before and two after the crystal) 40 m 5 m This system could be used also for high intensity beam and ion beam F. Murtas CERN 10 -Nov-2009 29