1 / 15

Proton detection with the R3B calorimeter, two layer solution IEM-CSIC sept. 2006 report

CONSEJO SUPERIOR DE INVESTIGACIONES CIENTÍFICAS. MINISTERIO DE EDUCACIÓN Y CIENCIA. Proton detection with the R3B calorimeter, two layer solution IEM-CSIC sept. 2006 report. O. Tengblad, M. Turrión Nieves, C. Pascual Izarra, A. Maira Vidal. outline. Why a two layer solution

phila
Download Presentation

Proton detection with the R3B calorimeter, two layer solution IEM-CSIC sept. 2006 report

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. CONSEJO SUPERIOR DE INVESTIGACIONES CIENTÍFICAS MINISTERIO DE EDUCACIÓN Y CIENCIA Proton detection with the R3B calorimeter, two layer solution IEM-CSIC sept. 2006 report O. Tengblad, M. Turrión Nieves, C. Pascual Izarra, A. Maira Vidal

  2. outline • Why a two layer solution • Limitations - requirements • “Conclusion”

  3. Energy loss of charged particles: Bethe-Bloch equation energy loss detected incident energy (MeV)

  4. Proposed scenario • Two layers detector: • Simplification Ë=f(D E1 )+ g(D E2) E D E1 D E2 the estimated final energy is proportional to the energy deposited in each layer

  5. SRIM Simulations: Deposited energy of protons Fit: Gaussian with a constant background

  6. SRIM Simulations: protons DE1+s(DE1) DE2+s(DE2) • Material: LaBr3(:Ce) • Thickness: 1mm+20mm • Monte Carlo: SRIM 2003 E D E2 D E1

  7. Energy resolution E DE1+D(sE1) DE2+s(DE2) sE? protons of 200MeV deposit an energy of: 1mm LaBr3= 1.49±0.23 MeV 20mm LaBr3= 31.32±1.13 MeV 200±50MeV (sE/E=25%) 200±10MeV (sE/E=5%)

  8. First Conclusions • If not fully stopped, two DE-detectors are required • A too thin detector gives bad estimation of the energy leading to bad resolution first detector should be thick in order to totally absorb protons up to rather high energy • Second detector placed to solve the ambiguity on the signal • The gammas will deposit most of the energy aroundthe first hit, which we want to be the first detector, why this crystal should have a good Eg resolution. • Two detectors of different materials with a unique PM or APD? Optically compatible

  9. Emission Absorption Detector spectral response matching • Emission and absorption spectra do not overlap » emitted light is not re-absorbed • Emission spectra shifted to lower energies • LYSO: • lexcitation [nm] =262, 293, 357 • Max. lemission [nm] =398, 435 Hautefeuille et al. J. of Crystal Growth (in press)

  10. Emission spectra NaI(Tl) CsI(Tl) BGO Max. lemission [nm] Decay time[ns] CsI(Tl) 550 1000 BGO 478 300 CsI pure 315 16 LYSO (Ce) 420 45-60 CsI(Na) 420 630 NaI(Tl) 400 230 LaBr3 (Ce) 380 16 LaCl3 (Ce) 350 28 LYSO LaBr3

  11. SRIM simulations: protons • Materials: LYSO(:Ce) + LaBr3(:Ce) • Thickness: 30mm + 20mm • Monte Carlo: SRIM 2003 D E1 D E2 E

  12. Energy resolution DE1+D(sE1) + DE2+s(DE2) E + sE? protons of 200MeV deposit an energy of: 30mm LYSO= 67.44±1.77 MeV 20mm LaBr3= 43.50±3.11MeV 200±7MeV (sE/E=3.5%) 200±10MeV (sE/E=5%)

  13. Gamma absorption • Minimum absorption for g ~5MeV • 55% of g absorbed in 30mm LYSO (Prelude)

  14. Second Conclusion • Protons • Two detectors are required to detect 300 MeV protons • The energy of the incident protons can be estimated with an error of ~3-4% with the LYSO + LaBr3(Ce) solution • Gammas • Most of the energy of the gammas is deposited around the first hit, why this should happen in the first layer! • 55% of g are absorbed in 30mm LYSO when the energy of the incident gammas is 5MeV • >55% of g are absorbed for E≠5MeV in 30mm LYSO • The rest will be absorbed in the second layer • If first gamma detected in second layer; event discarded • However, the gamma resolution in LYSO is about 6% • If this g-resolution is good enough one would choose LSO + LYSO as the resolution of LaBr is too good to be place as second layer.

  15. Final Conclusion • To obtain the optimum situation both for protons and gammas; • First crystal layer relatively thick and of a material with excellent gamma resolution,  LaBr3(Ce) of 30 mm l= 380nm decaytime= 16ns • Second crystal layer of a material emitting at shorter wavelength and with a decay constant different in order to separate the signals and that the second detector is transparent to the first.  LaCl3(Ce) of 150 mml= 350nm decaytime= 25ns This will detect protons up to 280 MeV with an proton energy resolution of the order of 2%. One could, however, live with a much shorter LaCl3(Ce) or one could combine the LaBr3(Ce) with pure CsI as a cheaper solution.

More Related