Kristian Larsson
Chalmers/GSI
R3B preparatory experiments
Extended experimental setup at Cave C
LAND at GSI and R3B at FAIR
SIS 100/300
Super
FRS
LAND
R3B
Extended experimental setup at Cave C.
Using detector systems that will be part of the R3B setup.
100 m
Experiment s223 – May 24 to June 4
Astrophysical reaction rates studied by Coulomb dissociation of radioactive beams – K. Sümmerer Coulomb Dissociation of 27P. 26Si(p,)27P reaction
Experiment s318 – August 5 to 13
Study of the Borromean dripline nucleus 17Ne
B. Jonson/T. Aumann
Nuclear interaction and proton removal cross sections
Transverse momentum distribution
Angular distribution of the decay proton from the unbound 16F system
Relative energy distributions in the 15O­p system
Continuum excitations in 17Ne
Angular and energy correlations
Experiment s296 – September 27 to October12
Quasifree hadronic scattering studies of exotic nuclei
R.C. Lemmon/T. Nilsson/O. Kiselev Radioactive beams in inverse kinematics to measure (p,2p) reactions
Extended ALADIN LAND setup at Cave C
Proposed R3B setup
Extended ALADIN LAND setup at Cave C
Proposed R3B setup
DSSDs in Cave C
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●
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6 AMS­like DSSDs are installed inside the Crystal Ball in Cave C
2 detectors are in the beam – measure protons and heavy ions
4 detectors form a recoil system around/after target
DSSD
•AMS type detectors
•DSSDs, 300 µm thick, 41 × 72 mm •Strip pitch 100 µm
•Energy resolution – 50 keV •Dynamic range – 100 keV ­ 14 MeV
•Sensors produced by CSEM/COLYBRIS
•1024 readout channels/detector •Designed to work in vacuum •Remote bias setting/control
•Remote temperature control
•9 detectors + FEE boards are available •Tested with β–source and beam at GSI
Oleg Kiselev
Readout for R3B DSSD
Two VME crates with SAM5 linked to 3 SIDEREM2 each, two GTB buses in use
Conversion + processing time ~ 100 µs ⇒ maximum rate 104 events/s (whole LAND DAQ – 2500 Hz)
Two test stands – at Daresbury and GSI will be made
DSSDs performance Detection of ions and protons
● Strange baseline behavior ⇒ Zero­
suppression is complicated
●
Oleg Kiselev
Experiments at Cave C  5 detectors was used in 27P Coulomb dissociation experiment s223
 6 detectors in 17Ne knock­
out and 12C Quasi­Free Scattering experiments, s318 and s296
 Two more runs in 2008? Proton readout from Crystal Ball
•Extra readout on PMs for Protons
•64 Crystals in the forward direction
Energy of a proton beam measured with a NaI crystal
Proton beam:
• E0 = 460 MeV → 451 MeV @ NaI
• E0 = 350 MeV → 339 MeV @ NaI
• E0 = 250 MeV → 237 MeV @ NaI
• E0 = 200 MeV → 185 MeV @ NaI
NaI crystal from Crystal Ball:
• length = 20cm
• absorbs up to 274 MeV protons
• additional readout: bypassing the
last amplifying stage of the PMT
→ gain factor reduced by ≈ 100
Felix Wamers/GSI
Raw spectra of protons in NaI crystal
protons penetrating
∆E = 142 MeV
protons penetrating
∆E = 178 MeV
mean: 1550 ch
sigma: 71 ch
mean: 1875 ch
sigma: 90 ch
4.5 % resolution
4.8 % resolution
protons stopped
∆E = 237 MeV
protons stopped
∆E = 185 MeV
mean: 2400 ch
sigma: 34 ch
mean: 2006 ch
sigma: 26 ch
1.4 % resolution
1.5 % resolution
Felix Wamers/GSI
R3B calorimeter and tracker
Tracker prototypes (AMS type)
Calorimeter geometry
Calorimeter w. inner tracker
Demonstrator
R3B fragment ID
GSI Large Acceptance Dipole – GLAD – CEA Saclay
Extended ALADIN LAND setup at Cave C
Proposed R3B setup
Drift chambers for proton tracking at the R3B setup
DCH 1
DCH 2
Christine Wimmer Universtät Frankfurt
DCH setup
• 2 detectors built at PNPI St . Petersburg and dedicated read­out system (cros3), linked to GSI standard (SAM), thanks to GSI electronic department • Final HV supply
• Final low voltage supply
Activities in 2007
• Early `07:
• March:
• May: • May/June: • July/August: • September/October: tests with Sr90 source
C12 test beam
p test beam
27
s223
P(γ,p)26Si
17
s318 Ne(γ,2p)15O 12
s296
C(p,2p)
Cell and detector geometry
16
m
m
counting gas: 20% CO2 +80% Ar
active area:
100 cm(x) 80 cm(y)
144 cells 112 cells
Reconstruction
Adjacent cells Calculate drift distance from drift time (Garfield)
Fit of x­t curve
r2
r1
Spatial Resolution
Method: correlation of 2 adjacent cells, assume constant angle of incidence
r2
r1
σa of r1+r2 = √2 σc
2 cells: σa = 303 µm
1 cell: σ c= 214 µm
r1+r2 [mm]
Efficiency
• Methode: per single track 4 fired cells per detector are expected (2x + 2y)
• 89% of p­tracks in ToF are fully reconstructed • single cell efficiency of 4√ 0.89 = 0.97
minor problems...
• 4 dead channels only out of 512
• readout is a little sensitive e.g. when HV is switched on/off, but stable during experiment conditions
• in first experiment some noisy channels, solved by arranging cables near readout electronic, can also be handled by offline analysis (ASDQ: time­over­threshold TOT)
Pattern spectra: Noise suppression ToT cell number
cell number
ToT
ToT
Christine Wimmer, Universtät Frankfurt
Next steps
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Software:
– Analysis (tracking algorithm)
– Simulation (Garfield): improve x­t curve
•
Hardware:
– More spare FEE boards for replacement
Extended ALADIN LAND setup at Cave C
Proposed R3B setup
New detector neuLAND
NeuLAND Detector Concept
Existing LAND detector:
• σt < 250 ps
• σx,y,z ≈ 3 cm
• Size: 2 x 2 x 1 m3
• Plastic scintillator / Fe converter sandwich structure
Th. Blaich et al., NIM A 314 (1992), 136
D. Rossi, Institut für Kernchemie, Uni Mainz
NeuLAND design goals:
• σt < 100 ps
• σx,y,z ≈ 1 cm
• Size : approx. 2 x 2 x 0.8 m3
• Efficiency > 90% for 1­n hits
• Improvement of multi­n recognition
Timing RPC concept:
• Total of 140 m2 RPC
• Approx. 10'000 channels
• Converter material: integrated in RPC structure
Compared to existing RPC types:
• Low count rates (< 1 Hz/cm2)
• Massive detector for higher efficiency
• Particles at various energies (non­
MIPs)
Resistive Plate Chambers
•
Gas detectors: 85% Reclin + 5% isobutane (absorbs UV photons) + 10% SF6 (electron scavenger)
•
•
•
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Initially developed for Minimum Ionizing Particles
Large uniform electric fields: 100 kV/cm
High resistivity → small currents
Low­cost materials → low cost­per­channel ratio
RPC detector principle
+
Gas
Glass
Gas
HV
­ +
­
D. Rossi, Institut für Kernchemie, Uni Mainz
Test Experiment Setup at KVI
Scintillator detector 2, with LAND PMs → Efficiency
Scintillator detector 1, with Hamamatsu R2083 PMs → Trigger
Proton beam
190, 120, 80­30 MeV LIP­Coimbra Test RPC
D. Rossi, Institut für Kernchemie, Uni Mainz
5 mm collimator
FOPI RPC
RPC Time Resolution: 120 MeV Protons
FOPI RPC; ­9.5 kV; 100­140 p/sec
σ t = 42 ps
FOPI RPC Efficiency > 90% (setup not optimized for efficiency measurements)
D. Rossi, Institut für Kernchemie, Uni Mainz
“Håkan's” Watcher “DAQ Scope”
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Looks at the raw data on­line
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Quick view if data make sense
Håkan T. Johansson Chalmers
Summary
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DSSDs works but needs zero­suppression •
Temporary Crystal Ball proton readout for correlation with the DSSDs, for R3B there will be the Calorimeter instead
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DCHs have proved to be working reliable in three exeriments
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Measured resolution for DCHs of 214 µm and cell efficiency of 97% in agreement with expected values