| Paper |
Title |
Page |
| WEOACH02 |
Gas Condensates onto a LHC Type Cryogenic Vacuum System Subjected to Electron Cloud
|
126 |
| |
- V. Baglin, B.J. Jenninger
CERN, Geneva
|
|
| |
In the Large Hadron Collider (LHC), the gas desorbed via photon stimulated molecular desorption or electron stimulated molecular desorption will be physisorbed onto the beam screen held between 5 and 20 K. Studies of the effects of the electron cloud onto a LHC type cryogenic vacuum chamber have been performed with the cold bore experiment (COLDEX) installed in the CERN Super Proton Synchrotron (SPS). Experiments performed with gas condensates such as H2, H2O, CO and CO2 are described. Implications to the LHC design and operation are discussed.
|
|
|
Video of talk
|
|
Transparencies
|
| WEPKF007 |
Vacuum Characterisation of a Woven Carbon Fiber Cryosorber in Presence of H2
|
1603 |
| |
- V. Baglin, H. Dupont, T. Garcin
CERN, Geneva
|
|
| |
Some of the cryogenic components in the Large Hadron Collider (LHC) will operate at 4.5 K. The H2 desorption will rapidly increase to the saturated vapour pressure, 3 orders of magnitude larger than the design pressure. Therefore, the use of cryosorbers is mandatory to provide the required pumping capacity and pumping speed. The behaviour of a woven carbon fiber to be used as a cryosorber has been studied under H2 injection. The pumping speed and capacity measured in the range 6 to 30 K are described. Observations made with an electron microscope are shown. A proposed pumping mechanism and the implications to the LHC are discussed.
|
|
| WEPLT044 |
Electron-cloud Build-up Simulations and Experiments at CERN
|
1930 |
| |
- F. Zimmermann, G. Arduini, V. Baglin, T. Bohl, B.J. Jenninger, J.M. Jimenez, J.-M. Laurent, F. Ruggiero, D. Schulte
CERN, Geneva
|
|
| |
We compare the predications of electron-cloud build-up simulations with measurements at the CERN SPS. Specifically, we compare the electron flux at the wall, electron-energy spectra, heat loads, and the spatial distribution of the electrons for two different bunch spacings, with variable magnetic fields, and for several chamber temperatures and associated surface conditions. The simulations employ a modified, improved version of the ECLOUD code. The main changes are briefly described. We finally present updated simulation results for the heat load in the cold LHC arcs.
|
|