K. A. Parker

Scanning facility to irradiate mechanical structures for the LHC upgrade programme

The existing luminosity of the LHC will be increased in stages to a factor of 10 above its current level (HL-LHC) by 2022. This planned increase in luminosity results in significantly higher levels of radiation inside the proposed ATLAS Upgrade detector. This means existing detector technologies together with new components and materials need to be re-examined to evaluate their performance and durability at these higher fluences. Of particular interest is the effect of radiation on the upgraded ATLAS tracker. To study these effects a new ATLAS irradiation scanning facility has been developed using the Medical Physics Cyclotron at the University of Birmingham. The intense cyclotron beams allow irradiated samples to receive in minutes fluences corresponding to years of operation at the HL-LHC. Since commissioning in early 2013, this facility has been used to irradiate silicon sensors, optical components and carbon fibre sandwiches for the ATLAS upgrade programme. Irradiations of silicon sensors and passive materials can be carried out in a temperature controlled cold box which moves continuously through the homogenous beamspot. This movement is provided by a pre-configured XY-axis cartesian robot system (scanning system). This paper reviews the design, development, commissioning, performance results and future plans of the irradiation facility, fully operational since 2013.

Recent results and experience with the Birmingham MC40 irradiation facility

Operational experience with the recently upgraded irradiation facility at the University of Birmingham is presented. This is based around the high intensity area of the MC40 medical cyclotron providing proton energies between 3 and 38 MeV and currents ranging from tens of fA to μA. Accurate dosimetry for displacement damage and total ionizing dose, using a combination of techniques, is offered. Irradiations are carried out in a temperature controlled chamber that can be scanned through the beam, with the possibility for the devices to be biased, clocked, and read-out. Fluence up to several 1016 1 MeV neq/cm2 and GRad ionizing dose can be delivered within a day.