munich-centre for advanced photonics a pixel detector system for laser-accelerated ion detection...
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Munich-Centre for Advanced Photonics
A pixel detector system for laser-accelerated ion detection
Sabine Reinhardt
Fakultät für Physik, Ludwig-Maximilians-Universität München, Germany
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
Detection of laser-accelerated proton (ion) beams:
• Ultra-short (<= ns) highly intense (> 107 ions/cm2) ion pulses
• EMP presence
• Mixed radiation background
• Large energy spread of ions
g Challenge for any electronic online detector
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
108 particles / cm²
=
1 particle / µm²
A, N constA
NΦ 1/4 A g 1/4 N
Pixel detector as online detector in Thomson spectrometer:
• real time measurement
• excellent spatial resolution
• good energy resolution
Investigated detector systems:
• Kappa DX-4 (commercial system)
• Timepix (scientific system)
collaboration with IAEP CTU Prague
• RadEye (commercial system)
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
Munich 14 MV Tandem accelerator
• Electrostatic accelerator
• protons: 8- 25 MeV
• 3 irradiation modes:
single particle
continuous
pulsed
107 protons /cm2/ ns
g similar to laser ion pulse
Unique possibilities to test detector response
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
Kappa DX-4
• Kodak CCD sensor KAI 1020
• 7.4 mm x 7.4 mm pixel size
• 2 mm depletion depth
• commercial system
• integrating detector
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
Summary
+ Dynamic range:
1 - 106 p/cm2/pulse
+ Linear response
+ Radiation hardness
(20 MeV, 107p/cm2):
1000 shots
- Charge sharing effects
- Small sensitive area
No choice for detector system
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
Timepix (in collaboration with IAEP CTU Prague)
• Medipix collaboration (CERN)
• hybrid detector system
• 300 mm Si-sensor
• 256 x 256 pixel (50 x 50 mm2)
• 3 different read-out modes:
• Medipix mode (counting)
• Timepix mode (time)
• TOT mode (energy)
Single event
Double event
cluster = adjacent pixel above threshold
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
No choice for detector system
+ Single particle response
+ Linear response
+ Good energy resolution
65 keV @ 5239 keV
- Large charge sharing effects
- Small sensitive area
- - Saturation and non-linear effects
2.5 . 105 p/cm2 /pulse
Summary
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
Rad Eye detector system
• RadEye 1 sensor
• Si-photodiode array
• 48 mm x 48 mm pixel size
• 2 mm depletion depth
• large sensitive area:
25 mm x 50 mm
• commercial system
• integrating detector
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
Munich 14 MV Tandem accelerator
• continuous beam
• 15 MeV protons
• ~ 104p/cm2/s
No charge sharing effects observed
Single and double hits can be distinguished
Cluster distribution:
Cluster pixel distribution:
single hit double hit
Single proton sensitivity
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
Munich 14 MV Tandem accelerator
• pulsed beam
• 20 MeV protons
• 104 - 107 p/cm2/ns
c d
a b
Good agreement to continuous measurements
No saturation observed
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
Munich 14 MV Tandem accelerator
• continuous + pulsed beam
• 20 MeV protons
• <= 6 .1010 p/cm2
Lifetime n 90% residual dynamic range
3000 shots
(20 MeV, 107p/cm2)
Radiation hardness
System ready for laser-ion-acceleration experiment !
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
MPQ Atlas laser
• 2.5 J, 30 fs,
• focal spot 3 mm (FWHM)
• 5-10 nm DLC foils
• wide angle spectrometer
dipole set 2 x 0.5 T
entrance slit 0.3 x 140 mm2
• Eproton > 1 MeV
RadEye-System
DLC foil Entrance slit
dipole set Al- foillaser
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
Pixel value spectrum:
Peak position n Energy loss
Peak content n Average number of proton hits per pixel
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
Sensor “C” Sensor “D”
g Good agreement with Tandem calibration
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
SRIM 2008:
Energy loss simulation
Energy conversion:
1.11 +/- 0.09 ADU/keV
Test with with a-source:
g good agreement
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
MPQ Atlas laser
• 400 mJ, 30 fs
• 20-40 nm DLC foils
• small angle spectrometer
only dipole 0.5 T
pinhole 2.5 mm
• Eproton > 4 MeV
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
Compact integrated system “RE4PC”
Stand alone system
computer control and read-out
electronics
Compact size: 30 x 25 x 25 cm3
Parallel read-out of 4 RadEye detectors
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
Astra Gemini laser
• 4-6 J, 50 fs
• focal spot: 3 mm (FWHM)
• target: 75 nm plastic foil
• p > 3.7 MeV
• C > 20 MeV
p
??
6+C
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
Conclusion
RadEye-Detector Single proton sensitivity Limited energy resolution Sufficient radiation hardness Linear pulse dose response up to 107 p/cm2
No problems with EMP in laser-environment
RE4PC Compact pixel detector system based on RadEye sensor developed Sensitive area as large as 100 x 50 mm2
Extension of functionality planned (trigger, read-out speed, ...)
RE4PC in routine use for laser accelerated proton and carbon ion detection
Instrumentation for Diagnostics and Control of Laser-Accelerated Proton (Ion) Beams: 2nd Workshop, Paris, France07.-08.06.2012
Munich-Centre for Advanced Photonics
Many thanks to
Wolfgang Draxinger, and Walter Assmann
Klaus Allinger, Jianhui Bin, Wenjun Ma and Jörg Schreiber
Carlos Granja and Frantisek Krejci
Thanks for your attention!