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FATIMA - Fast Timing Array
Status Report
Alison Bruce on behalf of
L.M. Fraile for the FATIMA collaborationGrupo de Física Nuclear, Dpto. Física Atómica, Molecular y Nuclear,
Universidad Complutense, E-28040 Madrid, Spain
FATIMA Helsinki 2013
Tapered LaBr3(Ce) design
L.M. Fraile – GFN-UCM
� LaBr3(Ce) detectors delivered to Madrid last week
→ “Studsvik design” optimized for light collection
→ returned to Saint Gobain for repair (bad E resolution)
→ under tests…
38 mm
47 mm
19 mm
16.5 mm
30.5 mm
FATIMA Helsinki 2013
UK has ordered, received and tested 31 detectors
ø1.5”x2”
FATIMA Helsinki 2013
Detector Characterisation
J. McIntyre et al., NIM A 652, 1, 2011, 201-204
Activity: ~0.7 counts/sec./cm3 ~0.1 counts/sec/cm3
EC
β-decay
α
0-255 keV
788-1000 keV 1.5-3 MeV
O.J.Roberts et al
FATIMA Helsinki 2013
EXILL-FATIMA campaign, ILL Grenoble
� EXOGAM + Fast timing LaBr3(Ce) array→ Nuclear spectroscopy of prompt fission fragments
→ 19 proposals on 85 nuclides
→ Thermal neutron induced fission of 235U target.
→ EXOGAM + 16 LaBr3(Ce) with digital DAQ for energy and analog
TACs for timing
L.M. Fraile – GFN-UCM
FATIMA Helsinki 2013L.M. Fraile – GFN-UCM
Detectors in use at RIKEN
Eurica + 18 LaBr3
FATIMA Helsinki 2013L.M. Fraile – GFN-UCM
FATIMA Helsinki 2013
Beta-delayed gamma-ray spectrum in 104Zr
L.M. Fraile – GFN-UCM
F.Browne et al to be published
FATIMA Helsinki 2013
Half-life of the first 2+ in 104Zr
L.M. Fraile – GFN-UCM
Plastic – LaBr time
t1/2 in the literature is 2.0(3) ns
t1/2 = 2.0(5) ns
F.Browne et al to be published
FATIMA Helsinki 2013
Potential FATIMA configurations
� 5 mm Mu metal included: (73% Ni, 17% Fe, 6% Cu, 4% Cr).
� Pb shielding included: 5 mm
� Al Housing included: 0.5mm
� MgO Insulation included: 0.25 mm
� Five energies simulated: 50, 100, 150, 200, 250 and 500 keV
� Five source positions (“Cases”) simulated to determine response.
Case 2
Case 3
Case 4
Case 1
Case 5
Middle Det.
Back . Front
Simulations done by O.J.Roberts (Brighton)
FATIMA Helsinki 2013
Design 1
� Approx. 10 cm to front of crystals
� 3 rings of 12 detectors, (36 detectors in total).
� All detectors 90o relative to beam.
O.J.Roberts et al
FATIMA Helsinki 2013
Design 6
• 4 rings of 36 detectors.
• One ring of 12 at 15o.
• One ring of 12 at -15o.
• One ring of 8 at 45o.
• One ring of 4 at 20o.
• The front of each detector is 13.5 cm away from the middle of AIDA.
O.J.Roberts et al
FATIMA Helsinki 2013
Design 6 Results
� Since Case 2=Case 4=Case 3=Case 5, only look at Case 2 and Case 5 along with Case 1.
� Case 1 is slightly lower than the other cases.
� 106 events in each Case
Case 2
Case 5Case 3
Case 4Case 1 Back Det. Front Det.
Middle Det.
O.J.Roberts et al
FATIMA Helsinki 2013
Design 8
� 4 Rings of 32 detectors in a “tiled” arrangement:
→ 8 detectors at -45o
→ 12 detectors at 75o
→ 8 detectors at 45o
→ 4 detectors at 20o
Similar to Design 6, but with the
1st ring at -45o in approx. 2 cm
closer. For other rings, detector
distance is 13.5 cm.
O.J.Roberts et al
FATIMA Helsinki 2013
Design 8 Results
� Since Case 2=Case 4=Case 3=Case 5, only look at Case 2 and Case 5 along with Case 1.
� Case 1 is slightly lower than the other cases.
� 106 events in each Case
Case 2
Case 5Case 3
Case 4Case 1 Back Det. Front Det.
Middle Det.
O.J.Roberts et al
FATIMA Helsinki 2013
Conclusions
� Designs 8 and 6 are similar, and the best.
Design 6Design 8
• Designs 4 and 5 follow in terms of efficiency.
Design 4
Design 5
1st
2nd
3rd
O.J.Roberts et al
FATIMA Helsinki 2013
Fatima – provisional design
15°30° 28°
27°
6°
Dave Seddon (Liverpool)/Ian Burrows (Daresbury)
FATIMA Helsinki 2013
Fatima + Aida
AIDA
SUPPORT STRUCTURES
EXISTING CARRIAGE SYSTEMS
FTA DETECTORS
MOUNTING BRACKETS
PROPOSED SETUP AT GSI
Dave Seddon (Liverpool)/Ian Burrows (Daresbury)
FATIMA Helsinki 2013
Timescales
L.M. Fraile – GFN-UCM
31 detector systems purchased by UK.
Spring 2014: Eurica + LaBr3 campaign (part 2) at RIKEN
Autumn 2014: Detectors used a focal plane of the
RITU/MARA separator at Jyvaskyla
Summer 2014: Test of array + AIDA + DAQ at GSI???