| dc.contributor |
LeBlanc, Benoit P |
|
| dc.contributor |
Majeski, Richard |
|
| dc.contributor |
Plasma Physics Department |
|
| dc.creator |
Jacobson, Craig |
|
| dc.date |
2014-03-26T17:10:46Z |
|
| dc.date |
2014-03-26T17:10:46Z |
|
| dc.date |
2014 |
|
| dc.date.accessioned |
2022-05-18T23:25:06Z |
|
| dc.date.available |
2022-05-18T23:25:06Z |
|
| dc.identifier |
http://arks.princeton.edu/ark:/88435/dsp01td96k2640 |
|
| dc.identifier.uri |
http://localhost:8080/xmlui/handle/CUHPOERS/48395 |
|
| dc.description |
The Lithium Tokamak Experiment (LTX) is a spherical tokamak designed to study the low-recycling regime through the use of lithium-coated shells conformal to the last closed flux surface (LCFS). A lowered recycling rate is expected to flatten core $T_\mathrm{e}$ profiles, raise edge $T_\mathrm{e}$, strongly affect $n_\mathrm{e}$ profiles, and enhance confinement.
To study these unique plasmas, a Thomson scattering diagnostic uses a $\le 20$~J, 30~ns FWHM pulsed ruby laser to measure $T_\mathrm{e}$ and $n_\mathrm{e}$ at 11 radial points on the horizontal midplane, spaced from the magnetic axis to the outer edge at a single temporal point for each discharge. Scattered light is imaged through a spectrometer onto an intensified CCD. The diagnostic is absolutely calibrated using a precision light source and Raman scattering. Measurements of $n_\mathrm{e}$ are compared with line integrated density measurements from a microwave interferometer. Adequate signal to noise is obtained with $n_\mathrm{e} \ge 2 \times 10^{18}\,\mathrm{m^{-3}}$.
Thomson profiles of plasmas following evaporation of lithium onto room-temperature plasma-facing components (PFCs) are used in conjunction with magnetic equilibria as input for TRANSP modeling runs. Neoclassical calculations are used to determine $T_\mathrm{i}$ profiles, which have levels that agree with passive charge exchange recombination spectroscopy (CHERS) measurements. TRANSP results for confinement times and stored energies agree with diamagnetic loop measurements. Results of $\chi_\mathrm{e}$ result in values as low as 7 m$^2$/s near the core, which rise to around 100 m$^2$/s near the edge. These are the first measurements of $\chi_\mathrm{e}$ in LTX, or its predecessor, the Current Drive Experiment-Upgrade (CDX-U), with lithium PFCs. |
|
| dc.language |
en |
|
| dc.publisher |
Princeton, NJ : Princeton University |
|
| dc.relation |
The Mudd Manuscript Library retains one bound copy of each dissertation. Search for these copies in the <a href=http://catalog.princeton.edu> library's main catalog </a> |
|
| dc.subject |
lithium |
|
| dc.subject |
tokamak |
|
| dc.subject |
transport |
|
| dc.subject |
Plasma physics |
|
| dc.title |
Electron Transport in Plasmas with Lithium-Coated Plasma-Facing Components |
|
| dc.type |
Academic dissertations (Ph.D.) |
|