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Mechanical and Fluidic Integration of Scintillating Microfluidic Channels into a Detector System
Context
Scintillators are materials that produces photons when exposed to particle
radiation. They are the active material of several particle detectors used in
the LHC, at CERN. Long exposition to the radiations will cause a light
output decrease and result eventually in a replacement of the detector.
This problem leaded a group of CERN
engineers and scientists to develop a new
microfluidic detector, where the damaged
liquid scintillator could be replaced by
pumping in order to increase the detector’s
lifetime. The aim of the project was to
circulate the liquid in the microchannels
for the first time and to investigate the pumping effects on the scintillator’s
light intensity.
Scintillating microfluidic channels for particle
detectors
Two main potential applications:
- Single particle tracking to know the
position of each particle
- Beam monitoring to know the global
energy distribution of the particle beam
Two main fields of application :
- High energy particle experiment as in the LHC
- Hadron-therapy : Alternative way to destruct tumor cells using particles
Liquid scintillator radiation damage
characterization
The development of a pumping system for the two potential applications
required more information concerning the radiation damage of the liquid
scintillator. An experiment was then planned to expose the liquid
scintillator to a proton beam and to characterize the scintillation decrease.
Temperature dependence of the scintillation
efficiency
The pumping of the liquid scintillator
in the microchannels could be
combined to a cooling process in
order to increase the detector’s
efficiency. A preliminary experiment
was then conducted to determine if
the scintillator used was subjected,
like other ones, to a temperature
dependence.
Author
Davy Brouzet
LAMD Laboratoire de Conception
Mécanique Appliquée
Pumping applied to the microchannels (1)
A whole chemically-resistant system was designed to connect a syringe to
various experiments related to the development of the microfluidic
detectors, including the ones carried out during this project.
Damaging the liquid using the photobleaching effect and pumping it
thanks to a syringe pump, the scintillator’s recovery in the microchannels
was proven experimentally.
Supervisors
Alessandro Mapelli
Pietro Maoddi
Prof. Jürg Schiffmann
Acknowledgements
Mikhail Asiatici
All the MicroScint project people
Pumping applied to the microchannels (2)
The flow rate/light output dependence and the possible light output
difference between the microchannels was also investigated
Principle of a
particle detector
Typical
microchannels
Preliminary results tend to
show a temperature
dependence of the scintillator
of a few percent per ten
degrees.
Temperature
dependence
experiment