• V.Kaplin, S.Karnaev, A. Kvashnin, I.Morozov, O.Plotnikova
  Budker Institute of Nuclear Physics, Novosibirsk, Russia

The temperature of the magnets is an important factor of the average energy stability of the circulating bunches. The work describes the VEPP-4M temperature measurement system based on 32 channel temperature controllers using High-Precision Digital Thermometers DS1621 and DS1631 with the resolution 0.02 and 0.06 degrees centigrade respectively. Temperature values are renewed for the all of 32 channels of each controller every second automatically. The controllers are connected to PC via serial interface RS232/RS485. The program running in PC inquires all controllers and writes data to database in terms of PostgreSQL at every minute. The graphic interface provides browsing of the temperature diagrams of the selected sensors over any period of time. The programs run under Linux and use Motif library.

235

• E.G.Miginskaya, I.I.Morozov, V.M.Tsukanov, A.A.Volkov
  Budker Institute of Nuclear Physics, Novosibirsk, Russia

Temperature variation of RF-cavities leads to a change of their geometrical sizes that provides undesirable cavity modes and to excitation of phase oscillations. It leads to decrease in luminosity and a beam life time. Flowing water heaters with stabilization of temperature have been established for elimination of this disadvantage. Temperature probes LM335 were used with a sensitivity of 10 мВ per degree. The power part is made on the controllable switches CPV240. The analysis of temperature of input and output temperatures of water is carried out by microcontroller ADAM connected to a computer by means of interface RS-485. The temperature variation have been reduced from 5 to 0.2 degrees centigrade. That has led to decrease in probability of occurrence of parasitical phase oscillations more than in 100 times.

253

• D.Gurov, O.Kiselev, I.Morozov, A.Ogurtsov, V.Petrov, E.Ruvinsky, A.Sukhanov K.Zhilayev
  Budker Institute of Nuclear Physics, Novosibirsk, Russia

• D.Cornuet, D.Gérard, W.Kalbreier, S.Ramberger, G. de Rijk
  CERN, Switzerland

The experimental insertions of the LHC employ normal-conducting magnets to provide for part of the beam separation and to compensate the effect of two large spectrometer dipoles. In the interaction regions IR1 for the ATLAS experiment and IR5 for the CMS experiment, each of the optical elements D1 for beam separation on either side of the experiment consist of 6 MBXW dipoles. Each magnet has a core length of 3.4 m, a large single aperture with a gap height of 63 mm and will operate in the field range up to 1.5 T. The MBXWT and MBXWS magnets are shorter versions of the MBXW magnet and will be used as vertical and horizontal compensation dipoles for the spectrometer dipoles in IR2 for the ALICE and in IR8 for the LHCb experiments respectively. The MBXWT and MBXWS have a core length of 1.5m and 0.75m respectively. Additionally on MBXW magnet serves as a main compensator for the LHCb experiment. The magnet design was done in collaboration between CERN and BINP and the dipole magnets are produced by BINP. So far all three MBXWS, all three MBXWT and thirteen of twenty-nine MBXW magnets including spares have been manufactured and delivered to CERN. The report presents the main design issues and results of the acceptance tests including mechanical, electrical and magnetic field measurements

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