P.50. E.G.Miginskaya, I.I.Morozov, V.M.Tsukanov, A.A.Volkov (Budker Institute of Nuclear Physics, Novosibirsk, Russia)
Temperature stabilization of RF- cavities of VEPP-4M Electron- Positron Facility
Temperature variation of RF-cavities leads to a change of their geometrical sizes that pro- vides 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 tempera- ture have been established for elimination of this disadvantage. Temperature probes LM335 were used with a sensitivity of 10 per degree. The power part is made on the controllable switches CPV240. The analysis of temperature of input and output tempera- tures 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 oscil-
lations more than in 100 times.
Dr. Ivan Ivanovich Morozov: email@example.com
P.51. Vladimir Ovchar, Eduard Kuper (Budker Institute of Nuclear Physics, Novosibirsk, Russia); Knud Dahlerup, Petersen Gert-Jan Coelingh.
ARC DETECTOR SYSTEM FOR EXTRACTION SWITCHES IN LHC CERN.
Cluster of 8 electro-mechanical D.C. breakers will be used for current interruption and fast extraction of magnetic field energy to dump resistors in the superconducting chains of main dipoles and quadrupoles in LHC (Large Hadron Collider), CERN, Switzerland. Par- allel connection (four brunches) and series connection (two in series) will be used in clus- ter for current and voltage matching. Contact erosion as usual occurs in the slowest branch, in two breakers from eight in cluster. The number of interruption is limited by contact erosion and some parts need replacement after some interruptions with arcs. The total number of breakers in the system is 256. For breakers resources registration and for prophylaxis works facilitation the 8 channels Arc Detector was designed. Each channel consists of light signal integrator, comparator and counter of events. Spark Detector for registration of discharges in power RF generators and feeders was designed on the base of Arc Detector
Vladimir Kirillovich Ovchar: firstname.lastname@example.org