Introduction:
Neutron irradiation (bare sensors + assemblies) shall be performed at Prague. Proton irradiation shall be performed at Los Alamos. Sensors should put under radiation up to
1x10^16 p/cm2.
Protons irradiation is trickier than neutron irradiation because the electronics is highly sensitive to proton radiation. FE-I3 chips have been designed to hold up to 1x10^15. It is therefore a problem if one wants to irradiate the assembly (3D + FE-I3) to higher levels. Another ingredient is that sensors should be irradiated under bias and cooled
(between -10 and -40 C).
Several solutions have been discussed:
- irradiate bare sensors and bump-bond afterwards. The problem is to deal with activated sensors (and surrounding equipment) and to do the bump-bonding while keeping the sensor cool
- the second solution would be to irradiate assemblies and shield the FE-I3 chip from the proton beam. Cinzia and Steve have proposed a shielding idea. There
are several issues to be worked out: how to build a fast removal setup of the sensor assembly from the shielding that could be significantly activated, how to increase the bias during the irradiation, how to measure the dose, how to align the beam wrt to the assemblies and shielding. It was suggested that SLAC would design and build the shielding. Simulation is required.
The second solution would be the default plan, but we should think of better alternatives.
Shielding for proton irradiation:
here is a drawing of principle for shielding the FE-I3 chips under proton irradiation:
Design of a cool box for testing the sensors
Los Alamos irradiation facility
Proton irradiation can be performed at the Los Alamos National Laboratory:
The deadline for submitting proposal for beam time is end of February. Information on how to submit proposals can be found here:
https://wnr-proposals.lanl.gov/index.shtml