KVI test experiment with existing RPC types

for NeuLAND

EXLEXL

RR33B and EXL Projects at FAIRB and EXL Projects at FAIR

• Reactions involving emission of projectile-like neutrons → high-energy neutron detector (300 MeV – 1 GeV)

NeuLAND Detector ConceptNeuLAND Detector Concept

Existing LAND detector:Existing LAND detector:• t < 250 ps• x,y,z ≈ 3 cm• Size: 2 x 2 x 1 m3

• Plastic scintillator / Fe converter sandwich structure

Compared to existing RPC types:Compared to existing RPC types:• Protons at various energies (non-MIPs)• Low count rates (< 1 Hz/cm2)• Massive detector for higher efficiency

NeuLAND design goals:NeuLAND design goals:• t < 100 ps• x,y,z ≈ 1 cm• Size : approx. 2 x 2 x 0.8 m3

• Efficiency > 90% for 1-n hits• Improvement of multi-n recognition

Th. Blaich et al., NIM A 314 (1992), 136

Timing RPC concept:Timing RPC concept:• Total of 140 m2 RPC• Approx. 10'000 channels• Converter material: integrated in

RPC structure

Neutron DetectionNeutron 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 Ep < 200 MeV

R3B Technical Proposal; http://www-land.gsi.de/r3b

Timing RPC TypesTiming RPC Types

A. Schüttauf, NIM A 533 (2004), 65 spacers (300 m)

FOPI RPCFOPI RPC

avalanche gapsLIP-Coimbra test RPCLIP-Coimbra test RPC

H. Alvarez Pol et al., NIM A 535 (2004), 277

Test Experiment Setup at KVITest Experiment Setup at KVI

Proton beam

190, 120, 80-30 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 ProtonsRPC Time Resolution: 120 MeV Protons

FOPI RPC Efficiency > 90% (setup not optimized for efficiency measurements)

t = 42 ps

FOPI RPC; -9.5 kV; 100-140 p/sec

RPC Time Resolution: 120 MeV ProtonsRPC Time Resolution: 120 MeV Protons

Results for LIP-Coimbra RPC:• Results with FOPI electronics• Measured efficiency: nearly 100%

t = 87 ps

LIP-Coimbra RPC; +6.25 kV; 100-140 p/sec

with walk correction

RPC Time Resolution: 40 MeV ProtonsRPC 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; +6.25 kV; 170 p/sec

Conclusions and OutlookConclusions 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 Ep < 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:GSI, Darmstadt:K. Boretzky, K. Mahata, K. Hildenbrand, H. Johansson, T. Le Bleis, A. Schüttauf, H. Simon

Institut für Kernchemie, Uni Mainz:Institut für Kernchemie, Uni Mainz: D. Rossi

KVI, University of Groningen (NL):KVI, University of Groningen (NL):N. Kalantar, L. Popescu, C. Rigollet du Toit, M. Vencelj, H. Wörtche

LIP, Coimbra (P):LIP, Coimbra (P): A. Blanco, P. Fonte

SINP, Kolkata (IN):SINP, Kolkata (IN): U. Datta Pramanik

for the Rfor the R33B and EXL CollaborationsB and EXL Collaborations

List of participants

Thank you