Plans are being formulated at CERN for a luminosity upgrade to the Large Hadron
Collider (LHC) machine. The LHC upgrade (SLHC) is being designed to increase the
luminosity from 1034cm-2s-1 to 1035cm-2s-1. The expected time-scale would be around
year 2015. The fluences at the SLHC will be 10 times higher than at LHC. For radii
greater than 20 cm the expected fluence is 1015 hadrons/cm2. It is not clear, if the
current opto-electronic components of the inner detector readout system are able to
cope with this challenging radiation environment of SLHC.
Previous radiation tests have shown that the opto-electronic components can survive
10 years of LHC operation. Radiation tests by the Pixel group have demonstrated that
these components can survive fluences and doses up to a factor of two higher than the
Therefore there is an open question of whether this type of opto-electronics could be
used on the upgraded SCT detector at the SLHC. This is a critical question for the
design of this detector as it will have a major influence on the layout of all the
readout services and therefore needs to be answered before the detector design can
advance very far.
We irradiated VCSEL and Si-Pin arrays at a 20 MeV neutron beam up to the levels
expected at SLHC and monitored their performance during irradiation and annealing. We
performed very low dose irradiations of SIMM fibres at a gamma source. The results
of these irradiations are summarized.