Speaker
Description
A highly flexible shattered pellet injection (SPI) system was installed in December 2021 on ASDEX Upgrade. This system provides three independent guide tubes (GTs) and the pellet velocity can be varied between 100-900 m/s depending on pellet size and composition. At the end of each GT, different shatter heads had been installed for characterization of the disruption behaviour for different shatter distributions.
In this talk we will discuss the results of the laboratory characterization, during which over 1300 different pellets were fired and their post-shatter shard distributions analysed. In total, 10 different shatter head geometries were compared and the fragment distributions were analyzed with the help of fragment tracking algorithms. Figure 1 shows a comparison between two pellets fired into a shatter head with a rectangular and circular cross-section, respectively.
Our results also show that there is a significant discrepancy (for the largest and smallest fragments) between measured distributions and those predicted by the currently employed pellet break-up models. We are going to share our experience with pellet creation and launching for in total over 1900 pellets and also first results of the ongoing ASDEX Upgrade SPI campaign.
Acknowledgements:
We would like to thank I. Vinyar for fruitful discussions.
| Speaker's title | Mr |
|---|---|
| Speaker's email address | paul.heinrich@ipp.mpg.de |
| Speaker's Affiliation | Max Planck Institute for Plasma Physics, Garching |
| Member State or IGO | Germany |
