A NEW TV BEAM OBSERVATION SYSTEM FOR CERN

Beam observation, emittance measurements and initial beam steering, are often achieved using scintillating or OTR (optical transition radiation) screens. In the CERN accelerators complex, this system is known as the BTV or MTV system. It consists of an observation camera, an illumination device and a vacuum tank provided of a view port containing the radiator. More than 100 such equipments, in several different flavours, are installed in the CPS complex, another 50 in the SPS complex and another 50 will be installed in the upcoming LHC. The newly developed electronics hardware consists of a single VME 64x card. This card is capable of controlling: all the different types of positioning mechanism for the screens, the adjustment of the illumination intensity, the different types of cameras (i.e. CCD or Vidicon tube) and the positioning of optical filters in front of the camera. Apart from the analogue video signal the card provides as output also the digitized image. A preserie of this new electronics has been installed and tested during the tests of the LHC beam transfer line TI8 last autumn. The production of 300 cards is now underway. These cards will be used for the complete renovation of the MTV system of the CPS complex[1] and for the installations in LHC and its transfer lines. In this contribution the new system is described with particular emphasis on the new VME card. The performances and limitations are also presented.