Plasma source development for fusion-relevant material testing

Journal Article · Mon May 01 00:00:00 EDT 2017 · Journal of Vacuum Science and Technology A

DOI:https://doi.org/10.1116/1.4982664· OSTI ID:1361355

Caughman, John B. O. ^[1]; Goulding, Richard H. ^[1]; Biewer, Theodore M. ^[1]; Bigelow, Timothy S. ^[1]; Campbell, Ian H. ^[1]; Caneses, Juan ^[1]; Diem, Stephanie J. ^[1]; Fadnek, Andy ^[1]; Fehling, Dan T. ^[1]; Isler, Ralph C. ^[1]; Martin, Elijah H. ^[1]; Parish, Chad M. ^[1]; Rapp, Juergen ^[1]; Wang, Kun ^[1]; Beers, Clyde J. ^[2]; Donovan, David ^[2]; Kafle, Nischal ^[2]; Ray, Holly B. ^[2]; Shaw, Guinevere C. ^[2]; Showers, Melissa A. ^[2]

---

1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2. Univ. of Tennessee, Knoxville, TN (United States)

Plasma facing materials in the divertor of a magnetic fusion reactor will have to tolerate steady-state plasma heat fluxes in the range of 10 MW/m2 for ~107 sec, in addition to fusion neutron fluences, which can damage the plasma facing materials to high displacements per atom (dpa) of ~50 dpa . Material solutions needed for the plasma facing components are yet to be developed and tested. The Materials Plasma Exposure eXperiment (MPEX) is a newly proposed steady state linear plasma device that is designed to deliver the necessary plasma heat flux to a target for this material testing, including the capability to expose a-priori neutron damaged material samples to those plasmas. The requirements of the plasma source needed to deliver this plasma heat flux are being developed on the Proto-MPEX device, which is a linear high-intensity radio frequency (RF) plasma source that combines a high-density helicon plasma generator with electron and ion heating sections. It is being used to study the physics of heating over-dense plasmas in a linear configuration. The helicon plasma is operated at 13.56 MHz with RF power levels up to 120 kW. Microwaves at 28 GHz (~30 kW) are coupled to the electrons in the over-dense helicon plasma via Electron Bernstein Waves (EBW), and ion cyclotron heating at 7-9 MHz (~30 kW) is via a magnetic beach approach. High plasma densities >6x1019/m3 have been produced in deuterium, with electron temperatures that can range from 2 to >10 eV. Operation with on-axis magnetic field strengths between 0.6 and 1.4 T is typical. The plasma heat flux delivered to a target can be > 10 MW/m2, depending on the operating conditions.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1361355
• Journal Information: Journal of Vacuum Science and Technology A, Vol. 35, Issue 3; ISSN 0734-2101
• Publisher: American Vacuum Society
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY