KVI test experiment with existing RPC types for NeuLAND

EXL R 3 B and EXL Projects at FAIR Reactions involving emission of projectile-like neutrons → high-energy neutron detector (300 MeV – 1 GeV)

NeuLAND Detector Concept Existing LAND detector:  t < 250 ps  x,y,z ≈ 3 cm Size: 2 x 2 x 1 m 3 Plastic scintillator / Fe converter sandwich structure Compared to existing RPC types: Protons at various energies (non-MIPs) Low count rates (< 1 Hz/cm 2 ) Massive detector for higher efficiency NeuLAND design goals:  t < 100 ps  x,y,z ≈ 1 cm Size : approx. 2 x 2 x 0.8 m 3 Efficiency > 90% for 1-n hits Improvement of multi-n recognition Th. Blaich et al., NIM A 314 (1992), 136 Timing RPC concept: Total of 140 m 2 RPC Approx. 10'000 channels Converter material: integrated in RPC structure

Neutron Detection High-energy neutrons (500 MeV) on Fe → production of charged particles via nuclear reactions Main contribution: protons at various energies KVI Test: protons at 190 MeV, 120 MeV and 80 – 30 MeV → investigation of time resolution for E p < 200 MeV R 3 B Technical Proposal;

Timing RPC Types A. Schüttauf, NIM A 533 (2004), 65 spacers (300  m) FOPI RPC avalanche gaps LIP-Coimbra test RPC H. Alvarez Pol et al., NIM A 535 (2004), 277

Test Experiment Setup at KVI Proton beam 190, 120, MeV Scintillator detector 1, with Hamamatsu R2083 PMs → Trigger Scintillator detector 2, with LAND PMs → Efficiency LIP-Coimbra Test RPC FOPI RPC 5 mm collimator

RPC Time Resolution: 120 MeV Protons FOPI RPC Efficiency > 90% (setup not optimized for efficiency measurements)  t = 42 ps FOPI RPC; -9.5 kV; p/sec

RPC Time Resolution: 120 MeV Protons Results for LIP-Coimbra RPC: Results with FOPI electronics Measured efficiency: nearly 100%  t = 87 ps LIP-Coimbra RPC; kV; p/sec with walk correction

RPC Time Resolution: 40 MeV Protons  t = 52 ps FOPI RPC; -9.5 kV; 150 p/sec 38 MeV 43 MeV  t = 82 ps LIP-Coimbra RPC; kV; 170 p/sec

Conclusions and Outlook Large detectors with high granularity can be built on RPC concept → offers excellent time resolution and cost-per-channel ratio Timing RPCs show good time resolutions for protons with E p < 200 MeV, with measured efficiencies between 90% and 100% → Timing RPC prototype development: –Adapted geometry (size, anode structure) –Converter material integrated in RPC structure

GSI, Darmstadt: K. Boretzky, K. Mahata, K. Hildenbrand, H. Johansson, T. Le Bleis, A. Schüttauf, H. Simon Institut für Kernchemie, Uni Mainz: D. Rossi KVI, University of Groningen (NL): N. Kalantar, L. Popescu, C. Rigollet du Toit, M. Vencelj, H. Wörtche LIP, Coimbra (P): A. Blanco, P. Fonte SINP, Kolkata (IN): U. Datta Pramanik for the R 3 B and EXL Collaborations List of participants Thank you

NeuLAND Working Group FZ Dresden-Rossendorf:FZ Dresden-Rossendorf: E. Grosse, A. Junghans, A. Wagner GSI, Darmstadt:GSI, Darmstadt: T. Aumann, K. Boretzky, H. Emling, K. Mahata, Y. Leifels, G. Schrieder ISS, Bucharest:ISS, Bucharest: M. Haiduc, C.M. Ilie, M. Potlog Jagellonski University, Krakow:Jagellonski University, Krakow: R. Kulessa Johann Wolfgang Goethe Universität, Frankfurt:Johann Wolfgang Goethe Universität, Frankfurt: J. Stroth Johannes Gutenberg-Universität, Mainz:Johannes Gutenberg-Universität, Mainz: J.V. Kratz, D. Rossi SINP, Kolkata:SINP, Kolkata: S. Bhattacharya, U. Datta Pramanik TU Darmstadt:TU Darmstadt: M. Elvers, J. Enders, L. Kern, D. Savran, A. Zilges University of Santiago de Compostela:University of Santiago de Compostela: J. Benlliure