Speaker
Dr
Michael Walsh
(ITER Organization, CS 90 046 - 13067 St Paul Lez Durance Cedex, France)
Description
Laser Aided diagnostics play a large role in ITER. This extends from basic control, to advanced control to the physics understanding. As ITER is the first Tokamak ever to be built that that is a Nuclear Facility, it brings with it a large range of challenges.
Typically, lasers are used in ITER for several key areas. These include Thomson scattering, line averaged density Interferometers, line averaged density - Interferometer-Polarimeters, internal q-profile Polarimeters, plasm current polarimeters, Erosion monitoring and Tritium monitoring. Lasers are further used to monitor the in-vessel as well as a very important use in the alignment of all the systems.
One thing that differentiates ITER and hence the techniques used from those deployed in the past is the fact that the systems have to be intelligent and find ways to self-calibrate and self-align. This is demanding that the design teams are pushing the boundaries of the current designs to reach the level needed for this modern and demanding Tokamak.
So far, the ITER team which is extended across the world has been developing many systems to address the above challenges. These include a self-aligning, fringe-hop eliminating scheme for the critical line average density measurements. These also include Thomson Scattering systems that can identify where they are pointing and react to the alignment in real time just to mention but a few.
There is also a need to develop interpretation algorithms that take in to account the new phenomena that will be measured as well as redundancy in the algorithms that are used for the critical measurements.
One particular issue that is shared amongst all these systems at different levels is the issue of the First mirror. To avoid neutrons escaping the confining boundary, mirrors are needed and these bring with them challenges. These challenges have and are still being addressed with excellent development in recent years.
While these systems have undergone already a significant amount of development, there is still a need to push the boundaries further and ensure that the operation of ITER will be made successful by the quality of the systems that provide the important measurements.
In this presentation, an outline of the different systems and approaches as well as some areas that need to be explored will be presented.
The views and opinions expressed herein do not necessarily reflect those of the ITER Organization.
Primary author
Dr
Michael Walsh
(ITER Organization, CS 90 046 - 13067 St Paul Lez Durance Cedex, France)
