JRA01: ACTAR Task J01-1: Physics constraints and detailed simulations Subtask J01-1-1: Physics constraints Subtask J01-1-1: Simulations Task J01-2: Test modules Subtask J01-2-1: detection/target gas Subtask J01-2-2: Readout chamber Subtask J01-2-3: Magnetic field configuration Task J01-3: Electronics and data acquisition Task J01-4: Particle tracking

Task J01-1 Physics constraints and detailed simulations Subtask J01-1-1: Physics constraints Task leader: B. Blank White paper achieved in November 2005 available via ftp://ftpcenbg.in2p3.fr/pub/nex/ACTARftp://ftpcenbg.in2p3.fr/pub/nex/ACTAR Subtask J01-1-1: Simulations Task leader: D. Cortina Framework constructed, first simulations performed

Overview of ActarSim H. Alvarez Pol USC

ActarSim : geometry

Physics constraints and simulations — Large dynamics needed: MeV — Either magnetic field or ancillary detectors (many) — Energy resolution: 50 keV for Si detectors =>10% at 0.5 MeV, 0.5% at 5 MeV Position resolution 0.25mm =>2.5% for 1cm, 0.25% for 10cm —Cubic geometry : Problem with deflection of the beam with B Solid angle reduced by factor 2(4) —Cylindrical geometry: Problem at small angles (ancillary detectors below 5°) Varying rise times of the pulses —Preliminary simultations in favor of cylindric geometry with longitudinal electric and magnetic field for reactions related to resonant elastic scattering, inelastic scattering (giant resonances) and transfer reactions. 2 main questions: Cubic or Cylindrical geometry? Magnetic field or not?

Definition of geometry for the next generation active target Active area R 7.5 – Altro boards 128 channels 20x200 mm (including cooling) R 300 Solenoid limit 1664 channels/quarter Cylindrical geometry: symmetry around beam axis E // beam axis, uniform Projection on the endcap of the cylinder B // beam axis Anode PadsASIC cards Cathode O 50cm Quantities to be measured: curvature radius, collected charge, range, angles For 0.5 mm position resolution,  E/E=2  R/R, expected energy resolution≈100 keV for  cm >20° 50cm

Simulations : 78 Ni(d,p) 79 Ni  cm =20° E x =0,1.5,3 MeV E x = 0, g.s. E x = 1.5 MeV E x = 3 MeV E inc = 8.5 A.MeV D 2 at 1atm X reac = 5 cm B=2 T Hector Alvarez-Pol, Esther Estevez-Aguado, USC

Task J01-2 Test modules Subtask T-J01-2-1: detection/target gas Subtask T-J01-2-2: readout chamber Subtask T-J01-2-3: magnetic field configuration For subtasks 1 and 2: Three test modules within ACTAR: Bordeaux TPC (B. Blank et al) using GEMS MAYA (W. Mittig, H. Savajols) and MAYAITO (F. Rejmund, A. Villari), both at GANIL and using wires Contact established with TACTIC group (York, TRIUMF) New test module under construction in collaboration with IPN Orsay and LAL for MICROMEGAS

Bertram Blank, CENBG TPC for 2p radioactivity studies

Daughter boards Hybrid boards GEM: Gas electron multiplier beam 1500 electronics channels Hybrid boards Daughter boards TPC for 2p radioactivity studies

TPC chamber Detector mount Electronics card Strip- strip matrix GEM  = 70  m d = 100  m TPC for 2p radioactivity studies

x energy | x time | y energy | y time Implantation at entrance Implantation at end saturation Different implantation depths by changing the B  Entrance of TPC Center of TPC End of TPC Threshold for implantation events Threshold for radioactivity events 48 Ca + 9 Be  26 P, 25 Si,…. x y beam Silicon detector TPC: implantation events

x energy | x time | y energy | y time Collimated  source  -delayed decay x y beam Silicon detector TPC : Decay events

MAYA-ITO test runs at GANIL F. Rejmund et al.

MAYA-ITO test runs at GANIL Beams used MeV/u MeV/u MeV/u MeV/u Gases: H,D,He,Ne,Ar,Xe, Isobutane

MAYA-ITO test runs at GANIL: 13 C results

TRIUMF Annular Chamber for the Tracking and Identification of Charged Particles Original concept: L. Buchmann, TRIUMF TACTIC: York-TRIUMF Collaboration

How is it going to work? ● 90% helium 10% CO2 gas mixture ● Pressure of a few hundred mbar ● Drift voltage ~100V/cm

Task J01-3 Electronics and Data acquisition Evaluation of existing ASICs 3 chips can fulfill the requirements for active targets: — GASSIPLEX (used in MAYA and MAYAITO) — ALTRO (developed for ALICE TPC) — T2K (developed for T2K experiment) Test module under construction in collaboration with Orsay will allow to test ALTRO in 2007 and T2K in 2008

L.Pollacco T2K ASIC (Tokai to Kamioka)

Read-out chamber ADC 10bits 10 & 40 MHz Power hungry (35 mW/channel) ALTRO for ALICE TPC

JRA 01 Milestones LoI presented at the SPIRAL2 SAC Meeting, October 2006 « Direct reactions with an active target » Spokerpersons: M.Chartier, D. Cortina, P. Roussel-Chomaz SAC recommendations received November 29th

JRA 01 Budget Remarks -France: all budget for personnel has been given to GANIL which redistributes to Bordeaux and Saclay. One postdoc starts at Bordeaux on December 15th for 9 months. Saclay will have 8 months in Spain (USC):one sudent has also started -GB (Liv+Daresbury): a large fraction of budget spent Remark: ACTAR probably extended until the end of Eurons (instead of end 2007) Ganil Bordeaux Saclay CCLRC Liverpool USC GSI

Detector: double-sided microstrip detector (CERN) GEM: Gas electron multiplier (CERN) Detector gas: P10 at 1atm Active detection volume: 15 x 15 x 15 cm 3 ASICS: VAT/TAT by IDEAS, Norway TAC window: 10  s channels per chip: 32 time and energy Electronics and data acquisition: PXI – VME Dead time: 1.5 ms (max) 4 GEMs to increase the gain new a source collimation system non-linearity of the gain (-30% on sides) retract drift frames TPC for 2p radioactivity studies