prof. peter mustermann | institut xxxxx | seite 1 dr. lothar naumann | institute of radiation...
TRANSCRIPT
Prof. Peter Mustermann | Institut xxxxx | www.hzdr.deSeite 1
Dr. Lothar Naumann | Institute of Radiation Physics | www.hzdr.de
Timing RPC for prompt gamma radiation detection
RPC 2016Lothar Naumann
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 2
E = 70 - 230 MeVI = 3 - 200 nA
• Proton therapy is a modern treatment for deep seated tumors
• Tumor dislocation or modification during the treatment period occurs
• Improvement of the proton therapy with online beam parameter settings
RPC for Proton Therapy
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 3
E = 70 - 230 MeVI = 3 - 200 nA
• Proton therapy is a modern treatment for deep seated tumors
• Tumor dislocation or modification during the treatment period occurs
• Improvement of the proton therapy with online beam parameter settings
PRC for Proton Therapy
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 4
E = 70 - 230 MeVI = 3 - 200 nA
• Proton therapy is a modern treatment for deep seated tumors
• Tumor dislocation or modification during the treatment period occurs
• Improvement of the proton therapy with real time range assessment
RPC for Proton Therapy
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 5
gantryPET
annihilation gamma
prompt gammaPrompt Gamma Spectrum
Treatment control
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 6
prompt gammaPrompt Gamma Spectrum
Treatment control
• Prompt Gamma Timing: Timing Detector timing resolution and count rate capabilities →RPC ?
• Prompt Gamma Imaging: Slit camera spatial resolution and count rate capabilities →RPC ?
• Prompt Gamma Origin: Compton camera spatial, time and energy resolutions and count rate capabilities → no RPC !
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 7
Ceramics RPC efficiency (sim.)
Compton scattering in a single ceramic sheet of 2 mm effects an escape of electrons and positrons
GEANT4 physics list QGSP_BIC_HP
energy spectrum of prompt γ-raysEp= 150 MeV; PMMA target
1.5 % electrons/γ
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 8
X-Rays@Electron accelerator (ELBE)
X-Rays energy spectra ≤ 20 MeVpulse duration 5 psflux ≤ 500 kHz/cm2
Electron beammonoenergetic , single electrons energy 12 - 40 MeVpulse duration 5 psflux ≤ 500 kHz/cm2
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 9
energy spectrum
X-Rays@ ELBE
beam size
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 10
Beampipe
RPC
X-ray monitorLaBr; BGO
E γ<12.5MeV
FWHMRF = 94 ps
X-Rays@ELBE
Reference timing: ELBE RF
Trigger: RPCOR & RF
Event distribution
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 11
Active area: 100 x 100 mm2 46 x 76 mm2
Bulk resistivity: ρ ~ 109 Ω cm ρ ~ 1012 Ω cmGas gaps: 2 x 2 gaps, 250 μm/gap 2 x 3 gaps, 250 μm/gap
Gas mixture: 85%Freon/10%i-Butane/5% SF6
Read-out electronics: GSI (FOPI)
L. Naumann et al., Nucl. Instr. Meth. A 628 (2011) 138 Kotte et al., Nucl. Instr. Meth. A 564 (2006) 155
RPC - design Ceramics RPC Glass RPC
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 12
Glass RPC- timing
𝑡𝑇𝑜𝐹=𝑡 𝑙𝑒𝑓𝑡+𝑡 h𝑟𝑖𝑔 𝑡
2
𝜎𝑅𝑃𝐶+𝐹𝐸𝐸=√𝜎𝑇𝑂𝐹2 −𝜎𝑅𝐹
2
Average over the whole detector:
E = 103 kV/cm RPC+FEE = 160 psE = 107 kV/cm RPC+FEE = 161 ps
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 13
Glass RPC – efficiency vs. flux
(6 gaps)
(4 gaps)
Eγ≤ 12.5 MeV
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 14
Ceramics RPC – efficiency vs. flux
(4 gaps)
Eγ≤ 12.5 MeV
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 15
RPC – efficiency
(6 gaps)
(4 gaps)
Eγ≤ 12.5 MeV
x 20
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 16
Ceramics RPC – timing vs.flux
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 17
• X-rays at ELBE are comparable to prompt gammas, generated by proton beams in human tissue
• GEANT4 simulations and experimental results of the detector efficiency have been compared. The results are in agreement for fluxes of 104 cm-²s-1 and amounts to 1.5 % per gap
• RPC with float glass electrodes shows in comparison to ceramics system an degradation of the rate capability by a factor of 20
• The time resolution is constant and amounts to FWKH = 150 ps up to the flux of 105 cm-²s-1
Conclusions
Dr. Lothar Naumann I [email protected] I Institut of Radiation Physics I www.hzdr.de Mitglied der Helmholtz-GemeinschaftSeite 18
20x20 cm²6 gas gaps, 250 μm/gap32 readout stripsPADI + VFTX
• Ceramics RPC for Prompt Gamma Timing
• Ceramics RPC for Prompt Gamma Imaging (slit camera system)
• Ceramics RPC test run with proton induced prompt gammas at OncoRay
Outlook
Prof. Peter Mustermann | Institut xxxxx | www.hzdr.deSeite 19
Dr. Lothar Naumann | Institute of Radiation Physics | www.hzdr.de
Acknowledgment:
HZDR - Dresden/Germany:A. Laso Garcia, J. Dreyer, B. Kämpfer, R. Kotte, H. Rohling, K. Römer, D. Stach, C. Wendisch
OncoRay - Dresden/Germany:G. Pausch
RPC 2016Lothar Naumann