munich-centre for advanced photonics a pixel detector system for laser-accelerated ion detection...

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!