TPC R3 B R3B – TPC Philippe Legou Krakow, February 2010 2nd CEA Saclay - France B TPC R3 © Ph. LEGOU & F.G. NIZERY plegou@cea.fr

2- Principle of detection 3- Construction of the detector: Outline 1- Motivation 2- Principle of detection 3- Construction of the detector: - the detector - the front-end electronics 4- Results plegou@cea.fr

R3B - TPC in few words … . What is it? R3B for : Reaction studies with Radioactive Relativistic Beams) What is it? ▪ a multi track Time Projection Chamber detector for protons to beam heavy ions. Why ? to measure precisely kinematics characteristics of particles with minimum amount of material in the beam. Who ? (for instance)  several teams of CEA Saclay : SPhN, SIS, SEDI  Cracovie (university and Nuclear Physics institute)  IN2P3 CNRS CPPM  Bratislava (Nuclear Physics Institute) Where ?  at GSI, just after GLAD magnet. When ? end of 2015 ? plegou@cea.fr

R3B hall in the FAIR facility Still to build FAIR GSI Cave C R3B plegou@cea.fr

the Mesh Micromegas : MICROMEsh GASeous Close-up of a mesh On behalf of Rui de Oliveira at CERN the Mesh Two way of making a mesh for a Micromegas design A Kapton foil streched and glued on a Frame, and the frame is screwed on the PCB A « bulk » which can be seen as Other layers of the PCB Improvements are possible (other gap) Ready to use solution Mounting operation is required No improvements + difficult to repair plegou@cea.fr

Micromegas used in TPC mode Micromegas : MICROMEsh GAS detector TPC: Time Projection Chamber Cathode Gas Ionization electrons Electrical field Mesh 100 µm Spacers Mother board with strips Beam plegou@cea.fr

Bulk Micromegas ▪ Large area and robustness ▪ Easy implementation ▪Low cost ▪Industrial process Bulk Micromegas obtained by lamination of a woven grid on an anode with a photo-imageable film « Bulk » : construction process Low material detectors plegou@cea.fr

Choice of the amplification gap electron Ion tail Small gap fast signals 12.5 m Micromegas has been tested for NA48-3 Ion collection time are <5 ns No Ballistic deficit plegou@cea.fr

a 100 µm mesh bulk detector No frame anymore ! Mesh 10×10 cm2 100mm kapton +5mm Cu plegou@cea.fr

R3B – TPC test setup in cave C October 2008 & March 2009 Six detectors along the beam between scintillators for the DACQ trigger Beam direction plegou@cea.fr

+ + a TracKer 48 channels Mother board Width of strips : 835 µm Very fast Preamp Space between 2 strips : 65 µm Or 7 channels of 5mm with 150 µm between 2 strips. plegou@cea.fr

Front-end module : FAMMAS (ph.Legou) ( Fast Amplifier Module for Micromegas ApplicationS) In few figures …   Power supply : + 5V -5V Consumption  50 mW Input: positive or negative Size: 22 x 20 x 5 mm weight : 4g Noise: 600 µV rms Rise time : < 1ns plegou@cea.fr

Characterization of the front-end in the lab Very good uniformity of the noise on the 48 channels front-end cards on each tracker detector plegou@cea.fr

CEA - FAMMAS Front-end module FAMMAS vs commercial Module Minicircuits 1GHz ZFL-1000LN CEA - FAMMAS Front-end module Amplitude width Amplitude width 3.07ns F4 F2 F4 2.57ns F2 Fall time 90% - 10% Rise time 10% - 90% Fall time 90% - 10% Rise time 10% - 90% 2.16ns F1 F1 1.11ns 1.08ns F6 0.8ns F6 plegou@cea.fr

Characterization of the detector Both detectors have the same gain in the area of the operating point. plegou@cea.fr

Test on a 100 µm gap detector at CERN Test conditions :  visualisation at about 30 meters coaxial cable.  Gaz : COMPASS.  Beam. Mesh Voltage : 350 V Mesh Voltage : 370 V plegou@cea.fr

Test on a 100 µm gap detector at CERN No crosstalk between neighbour channels Test conditions :  visualisation at about 30 meters coaxial cable.  Gaz : COMPASS.  Beam. Mesh Voltage : 340 V Mesh Voltage : 340 V plegou@cea.fr

Tests on a 100 µm gap Bulk detector at GSI … 2008, october 19th. Test conditions :  visualisation at about 30 meters coaxial cable.  Gaz : P10  Beam. Mesh Voltage : 380 V Drift Voltage : 2000V plegou@cea.fr

Resistive micromegas detectors By adding a resistive foil (2MΩ/□ ) on the strips we can spread the charge on several strips. M. Dixit et al. (Carleton U. – Ottawa) Micromegas mesh Resistive foil Glue Pads plegou@cea.fr

Signals on resistive Bulk detectors Pics from the scope of two neigbourg strips plegou@cea.fr

Response of three neighbour strips seen by the ADC plegou@cea.fr

Tests on a resistive 100 µm gap Bulk detector at GSI March 2009 in Cave C. Classical detectors The charge is more spread on resistive detectors « classic 835 µ » « resistive 835 µ » « resistive 5 mm » plegou@cea.fr

The « One meter » detector test - station One meter station @ saclay in « lab #534 » The elctrical field cage Electric field cage To provide an uniform fieldIn the whole convertion gap ≈2m Aim of this detector : to test the real drift distance plegou@cea.fr

R3B – TPC @ GSI End Cap Gas enclosure Detection boxes 1,6 m ≈ 8 m plegou@cea.fr

R3B TPC … the just after GALD magnet and the Helium tank… . GLAD magnet ≈4 m plegou@cea.fr

Tracks seen by all the chambers C 835 µm C 835 µm R 835 µm R 5 mm R 5 mm C 835 µm plegou@cea.fr

Pads response function of the pads classical 835 µm   resistive 835 µm  resistive 5 mm plegou@cea.fr

- the transfert properties of the magnet. Taking into account : - the transfert properties of the magnet. - the multiple scattering from the target point to the detector. We need a position reconstruction in the TPC of 200 µm RMS plegou@cea.fr