| Autor: |
U. Timm, S. Schreck, C. Juhnke, M. Mattern-Klosson, H.-U. Häfner, H.-J. Mundinger, H. H. Klein |
| Rok vydání: |
1993 |
| Předmět: |
|
| Zdroj: |
Vacuum. 44:717-719 |
| ISSN: |
0042-207X |
| DOI: |
10.1016/0042-207x(93)90132-t |
| Popis: |
According to the PNEUROP-acceptance rules for cryopumps the crossover is defined as the maximum amount of nitrogen (mbar I) which can be pumped by the cryopump within a short interval, whereby the temperature of the cryopanels must not exceed 20 K. Measurements carried out with a standard refrigerator-cooled cryopump (intake flange DN 200) have shown that the present definition is not sufficient. The temperature rise caused by the gas flow mainly depends on the preloading of the pumping surfaces. The report proposes a new, more complete and practicable definition of the crossover. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
