| Zugriffsnummer | 30562 |
| Dokumenttyp | Zeitschriftenartikel |
| Sprache | Englisch |
| Titel | Temperature relaxation of argon and helium after injection into a vacuum vessel |
| Autor(in); Institution |
Jousten, Karl; 9.14, Vakuumphysik, PTB-Berlin
|
| Quelle/Jahr | Vacuum: 45 (1994), 2, 1205 - 1208 |
| ISSN | 0042-207X |
| DOI | |
| Verlag | Amsterdam: Elsevier |
| Zusammenfassung | When gas is transferred from a vessel with high pressure to a vessel with much lower pressure or a vacuum, considerable flow velocities larger than sonic speed or average thermal speed may occur. Since the transfer is adiabatic for a short period, the gas injected into a vessel is getting much warmer than the surrounding walls, while the gas remaining on the high pressure side, which is performing accelarating work, cools down considerably below ambient temperature; this happens even if the gas is ideal. We have investigated this effect experimentally and determined the relaxation time of the temperature for Ar and He. The measured temperature differences of the gas to the surrounding walls were as much as 20 K, when gas was transferred from a volume 1 l / with 300 kPa to high vacuum. The relaxation could be fitted with the sum of three exponential functions, with the time constants ranging from a few seconds up to 10 min. These different time constants can be related to the physical processes involved. |
