04/15/2009 | CALIFA Working Group Meeting | GSI, Darmstadt | Linda Schnorrenberger

Measuring CsI Response Functions @ NEPTUN

Feasibility test with Santiago’s ProtoZero

L. Schnorrenberger1, H. Alvarez-Pol2, J. Benlliure2, D. Cortina-Gil2, I. Duran2, M. Gascon2, J. Glorius1, D. Gonzales2, B. Löher1, N. Montes2, N. Pietralla1, D. Savran1, V. Simon1

und K. Sonnabend1

1Institut für Kernphysik, TU Darmstadt, Germany

2 Universidade de Santiago de Compostela, Spain

Supported by BMBF (06 DA 9040 I), DFG (SFB 634) and LOEWE (HIC for FAIR)

SFB 634

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Photons are produced by the effect of bremsstrahlung Idea: determine energy of electron to deduce photon energy

Conservation of energy: E= E0 - Ee

Principle of Photon Tagging

4 cm

Specifications E: 2-20 MeVE: 25 keV @ 10 MeV E-window: 1-3 MeV

4 cm

Focal Plane Detector array

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ProtoZero

R3B @ FAIR: CALIFA 90° Prototype

13 cm

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ProtoZero Single-Response Function

Two energy windows measured: 2.6 – 3.9 MeV 6.2 – 7.1 MeV

Coincidence spectra “fiber 70” – “PZ trigger” (60 ns gate) (would have liked to choose center crystal as trigger)

Scaled by 0.5! FE

DESE

SE

DEFE

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Single-Response Function of Array

511 keV 2925 keV

beam spot on center crystals6364 keV

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Outlook / Improvements

Use trigger different from Mesitec shaper/cfd/timing moduleWork on better collimated beam (now: 2-3 cm)

Test Addback responseAdditional EnergiesComparison with GEANT4… SFB 634

BMBF (06 DA 9040 I)