micos a cherne collaboration in applied research involving industry françois tondeur, lara marwaha,...
TRANSCRIPT
MICOSa CHERNE collaboration
in applied research involving industry
François Tondeur, Lara Marwaha, Isabelle Gerardy, Jonathan Baré
ISIB José Rodenas, Sergio Gallardo
UPV
MICOSminiaturisation of the Compton
spectrometer
• PRINCIPLE
Measurement on the scattered X-ray beam to avoid detector saturation
The Compton spectrometer in the 1990’s
• Matscheko et al RTI Electronics
A big, heavy device adapted to a Ge detector
The Compton spectrometerin CHERNE
• UP Valencia: Gallardo, Rodenas, Verdu Monte Carlo simulation of the Compton scattering technique applied to characterize diagnostic X-ray spectra
• U. Bologna: Fernandez, Scot, Baré et alReconstruction of the X-ray tube spectrum from a scattering measurement
• ISIB Bruxelles: Marwaha, Tondeur et alpresent work
MICOS
• Development of a small portable device for routine spectrometric controls of X-
ray generators• 4-year FIRST project supported by the
Walloon region 2008-2012• Industrial cooperation with Balteau
NDT and Canberra Benelux• Academic collaboration with UP
Valencia
MICOS partnership
• Project coordinated by ISIB, and executed at ISIB lab of nuclear and radiation physicsresearch fellow: Lara Marwaha (ex-FHA)
• UPV: training of the research fellow to MC simulation and to the « old » spectrometer
• Balteau: manufacturer of the shielding + sales in the industrial sector
• Canberra: provided detectors for the project + sales in the medical sector
MICOS main steps
• Design of a simplified shielding
• Tests of detectors and choice of a detector
• MC simulation and validation
• Choice of the methodology for unfolding
Shielding design• 3 options according
to energy : maximum 150, 300 or 450 keV
• Design with MC simulation
• Steel/lead/copper for 150 kV and 300 kV
• 450 kV: W cover above the 300 kV device
Choice of the detector
• Limited choice of « pen-type » detectors diam.<20 mm, reasonable cost
• Tested : CZT, CdTe, NaI• CZT- CdTe: not easy to simulate with MC
(problems with dead layers, variability from one detector to another, response depending on electronics settings…)
• Choice: NaI – easy to simulate with MC
Monte Carlo simulation• Geometrical model validated with
radioactive sources: 241Am, 109Cd, 57Co, 137Cs
thickness of front
window fitted to
experimental data
• Response matrix of 150 keV prototype calculated with 1 keV interval
Deconvolution• A specific algorithm similar to GRAVEL
gives good results in few iterationssensitive to good energy calibration
MICOS going on
• 300/450 keV prototype soon manufacturedsimulation-validation-unfolding-testing
• Back to CZT/CdTe improve the geometrical model and the
simulation of the response
• Students from CHERNE welcome for a master thesis
Thank you