Detection of Low Energy Particle EURONS-JRA4 DLEP

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Detection of Low Energy ParticleEURONS-JRA4 DLEP
University of Århus, Denmark H. Fynbo
CSIC, IEM, Madrid, Spain O. Tengblad
University of York, UK B.R. Fulton
University of Jyväskylä, Finland A. Jokinen
Chalmers University of Technology Göteborg,
Sweden T. Nilsson
Acqiris http//www.acqiris.com/
MESYTEC http//www.mesytec.de
Micron Semiconductors UK http//www.micronsemicond
uctor.co.uk/
ISOLDE-CERN
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DLEP - Physics motivation b-decays of exotic
nuclei

• b-decays of drip-line nuclei
• ? Many open channels with particle emission
• Charged particles (p,d,t,a,6He,...)
• Neutrons
• Multiparticle emission (2-4n,2a,2p...)
• ? Often low energy ( lt 1MeV)

Dedicated effort for Detection of Low Energy
Particles from Exotic b-decays
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Region of interest Light exotic Nuclei

• Exact A-body calculations possible for A?12
• Shell-model states
• Molecular-cluster states
• We can cover from drip-line to drip-line
• Break-up mechanism not fixed by kinematics
• Sequential?
• Direct?
• Crucial for bridging the
• A5 and A8 gaps in Big Bang and Stellar nuclear
  synthesis.

12C The triple alpha process 4He 4He ? 8Be
8Be 4He ? 12C ? 7.367 MeV
a clustering
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9C
b
a
a
a
p
9Li
b-
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b-decay experiments

• Segmented Si-Detectors
• Large Solid Angle
• detect all particles
• High Segmentation
• no summing

• ISOL beam
• Low energy isotope separated beam
• Can be stopped in C-foil
• Well-defined source

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12C
R. Raabe
H. Fynbo
12N/B
Reaction studies _at_ tandem in Madrid 3He 10B
? 12C ? p ? ? ?
12N/B
O. Tengblad
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Triple coincidence in the b-decay of 12N
H. Fynbo et al., Revised rates for the stellar
triple-a process from measurements of 12C nuclear
resonances Nature 433 (2005) 136
C.Aa. Diget et al., Properties of the 12C 10 MeV
state determined through ß-decay, Nucl.Phys. A
760(2005)3-18
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Reaction studies _at_ tandem in Madrid
17 mg/cm2
3He _at_ 2.45 MeV

12C
9B
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INPC2007
p ? ? a coincidences ? Excitation
Energy in 12C reconstructed
SE?
12C
?1
8Be(0)
?2
?3
We can deduce the partial branching ratios for
each level in 12C via the 0 and 2 states in
8Be
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Task deliverables

• Design and prototyping of
• Detectors Front end electronics for low energy
  Charged particle detection
• Algorithms for digital
• particle identification

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Detectors ultra thin window
200 nm Al 400 nm doping
?
New design 100 nm doping Grid contact
100 nm dead layer 60 mm ? no b response
Developed in cooperation with our industrial
partner Micron Semiconductor
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Detectors - monolithic Si telescope
DE
E
256 detector elements á 9 mm2 32 readout channels
64 detector elements á 7 mm2 128 readout channels
multiplexed to 1 ADC.
Solid Angle 20 of the DSSSD BUT! 4
times more electronic channels
DE stage 1 µm E stage 400 15 µm
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Detector delivered August 2007
Doped cut Si-wafer from SGS-THOMSON -Catania,
detector assembly by DLEP and industrial partner
MESYTEC
64 monolithic telescopes ? 128ch on 5x5cm2
Area 64x 7mm2, DE 1mm, E 400 mm
Side view with connectors
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Complete readout electronicDelivered August
2007developed for DLEP by MESYTEC
64 ch PA TFA CFD A trigger Analogue
multiplexed
10M samples/bus 12 bit ADC
½ liter
256 ch
256 ch
4x 16ch cards
Incorporated into the MIDAS DAQ by Vic Pucknel,
RAL Daresbury
In big production estimated cost of complete
readout chain 70 /ch
MDI-2 VME sequencer and ADC handles 512
multiplexed channels
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IS417 ISOLDE 28 Sep- 5 Oct 11Li beta decay
channels
Charged particle spectrum
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Task deliverables

• Design and prototyping of
• Detectors Front end electronics for low energy
  Charged particle detection
• Algorithms for digital
• particle identification

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PSD Poster P2 and P7
The WavePro 7000A 4 input channels 1GHz
bandwidth 20GS sampling frequency
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Pulse rise time vs Amplitude
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Neural Network Analysis Poster P7
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Collaborators

• H.O.U. Fynbo, C. Aa. Diget, S.G. Pedersen, K.
  Riisager,
• Department of Physics and Astronomy, Århus
  University, Denmark

• M.J.G. Borge, M. Madurga, M. Alcorta, D. Galaviz
  ,
• O. Tengblad, M. Turrion
• Instituto Estructura de la Materia, CSIC,
  Madrid, Spain

• J. Äystö, W. Huang, J. Huikari, A. Jokinen, P.
  Jones,
• Department of Physics, University of Jyväskylä,
  Finland

• B. Jonson, T. Nilsson, G. Nyman, H. Johansson
• Fundamental Physics, Chalmers Univ. of
  Technology, Göteborg, Sweden

• K. Riisager, L.M. Fraile, , H. Jeppesen
• ISOLDE, EP-Division, CERN, Geneva, Switzerland

• B. Fulton, P. Joshi, S.Fox
• University of York, United Kingdom.

• P. Dendooven

• I. Martel, J.L. Flores, P. Salmerón
• Universidad de Huelva, Sapin

• R. Raabe