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Sabine Reinhardt Fakultät für Physik, Ludwig-Maximilians-Universität München, Germany . A pixel detector system for laser-accelerated ion detection. Detection of laser-accelerated proton ( ion ) beams :. Ultra- short (<= ns ) highly intense (> 10 7 ions /cm 2 ) ion pulses
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Sabine Reinhardt Fakultät für Physik, Ludwig-Maximilians-Universität München, Germany A pixel detector system for laser-accelerated ion detection
Detectionoflaser-acceleratedproton (ion) beams: • Ultra-short (<= ns) highlyintense (> 107ions/cm2) ionpulses • EMP presence • Mixed radiation background • Large energy spread of ions g Challenge for any electronic online detector
Pixel detector as online detector in Thomson spectrometer: • real time measurement • excellent spatial resolution • good energy resolution • 108particles / cm² • = • 1 particle / µm² • Investigated detector systems: • Kappa DX-4 (commercial system) • Timepix(scientific system) • collaboration with IAEP CTU Prague • RadEye(commercial system) A, N 1/4 A g1/4 N
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
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
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
Timepix(in collaborationwith IAEP CTU Prague) • Medipixcollaboration (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
Summary • + 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 No choice for detector system
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
Single proton sensitivity Cluster pixel distribution: • Munich 14 MV Tandem accelerator • continuous beam • 15 MeV protons • ~ 104p/cm2/s Clusterdistribution: double hit single hit No charge sharing effects observed Single and double hits can be distinguished
Munich 14 MV Tandem accelerator • pulsed beam • 20 MeV protons • 104 - 107 p/cm2/ns No saturation observed Good agreement to continuous measurements a b c d
Radiation hardness • Munich 14 MV Tandem accelerator • continuous + pulsed beam • 20 MeV protons • <= 6 .1010 p/cm2 Lifetime n 90% residual dynamic range 3000shots (20 MeV, 107p/cm2) System ready for laser-ion-acceleration experiment !
dipole set Al- foil • 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 DLC foil RadEye- System Entrance slit laser
Sensor “C” Sensor “D” g Good agreement with Tandem calibration
SRIM 2008: Energy loss simulation Energy conversion: 1.11 +/- 0.09 ADU/keV Test with witha-source: g good agreement
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
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
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 ??
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
Manythanksto Wolfgang Draxinger, and Walter Assmann Klaus Allinger, JianhuiBin, Wenjun Ma and Jörg Schreiber Carlos Granjaand Frantisek Krejci Thanks for your attention!