Introduction

In the SPS and LHC BGIs an optical readout is used. The images of the beam are registered using ThermoFisher (currently named Thermo CIDTEC) I8712D1M-XD4 CID intensified camera (in the link non-intensified version is shown).

This cameras produce analog video signal which is amplified in the tunnel and send to the frame grabber in the VME card.

The cameras are shall work even after receiving doses of about 1 MRad (tested with gammas). Nevertheless camera failures for much smaller doses at SPS and LHC have been encountered. Investigation by the manufacturer led to suggestion that the radiation-sensitive component is microcontroller Silicon Labolatories C8051F121 (enclose the datasheet).

The cameras in which microcontroller failed (4 out of 5) were modified: the microcontrollers were moved from camera head to external box which will be installed on the floor of the tunnel and shielded.

Gain and gate control

Cameras have buil-in MCP-unit which allows to increase its sensitivity. The image acquisition can also be gated down to 10 ns. The gain and gate settings are controlled through RS485 interface.