Noble gas exhaust with a stri=ongly baffled divertor in ASDEX-Upgrade
Since spring of 1997 ASDEX Upgrade has operated with the new divertor II (LYRA), which is characterisd by vertical target plates, tight baffling towards the main chamber, and a dome baffle in the private flux region. The main goal of this divertor modification was to increase the divertor density for a given plasma density, whereas the neutral density in the main chamber should be similar or even lower. Pumping occurs now from the private flux region which is linked to the pump chamber by finite conductance below the outer target. A cryo-pump has been installed in the outer divertor chamber in addition to the turbo pumps. This divertor scheme is very similar to the one planned for ITER. First experiments with the new divertor indicate that the compression of helium, is much higher in the new divertor, while the neon exhaust efficiency. The cryo-pump can strongly enhance the scrape-off layer flow of deuterium, resulting in a small improvement of the He exhaust rate.
Bibliographic Reference: Article: Journal of Nuclear Materials, 266-269 (1999), 462-466
Record Number: 199910743 / Last updated on: 1999-05-21
Original language: en
Available languages: en