학술논문

Massive pellet and rupture disk testing for disruption mitigation applications
Document Type
Conference
Source
2009 23rd IEEE/NPSS Symposium on Fusion Engineering Fusion Engineering, 2009. SOFE 2009. 23rd IEEE/NPSS Symposium on. :1-4 Jun, 2009
Subject
Fields, Waves and Electromagnetics
Nuclear Engineering
Tokamaks
Gases
Laboratories
Cryogenics
Refrigeration
Boring
Acceleration
System testing
Assembly
Argon
plasma
disruption
mitigation
gas injection
massive pellet
rupture disk
Language
ISSN
1078-8891
2155-9953
Abstract
Injection of massive quantities of noble gases or D 2 has proven to be effective at mitigating some of the deleterious effects of disruptions in tokamaks. Two alternative methods that might offer some advantages over the present technique for massive gas injection are “shattering” massive pellets and employing close-coupled rupture disks. Laboratory testing has been carried out to evaluate their feasibility. For the study of massive pellets, a pipe gun pellet injector cooled with a cryogenic refrigerator was fitted with a relatively large barrel (16.5 mm bore), and D 2 and Ne pellets were made and were accelerated to speeds of ∼600 and 300 m/s, respectively. Based on the successful proof-of-principle testing with the injector and a special double-impact target to shatter pellets, a similar system has been prepared and installed on DIII-D and should be ready for experiments later this year. To study the applicability of rupture disks for disruption mitigation, a simple test apparatus was assembled in the lab. Commercially available rupture disks of 1 in. nominal diameter were tested at conditions relevant for the application on tokamaks, including tests with Ar and He gases and rupture pressures of ∼54 bar. Some technical and practical issues of implementing this technique on a tokamak are discussed.