TJ-II:LIA-TOF. New method for Edge Ti determination in TJ-II
Experimental campaign
2019 Autumn
Proposal title
Impurity transport studies by Li Ablation-TOF detection: New method for Edge Ti determination in TJ-II
Name and affiliation of proponent
F Tabares
Details of contact person at LNF
If applicable, enter contact person here or write N/A
Description of the activity
Background: Although several methods for the measurement of Ti at the edge of TJ-II have been tried (RFA, He beam, Doppler spectroscopy…) no systematic recording of this important parameter has been achieved so far.
Description: The NdYag laser used for Blow Off experiments will be focussed into the vacuum vessel opposite to it. A lens will control the local power density; in order to produce the right dose of Li compatible with normal plasma operation, similar to those induced by pellet injection now. Fast recording of the Time of Flight of the LI+ emission toroidally away from the source will provide the energy distribution of the thermalized particles and hence the value of the Ti of the background plasma can be deduced.
International or National funding project or entity
N/A
Description of required resources
Required resources:
- Number of plasma discharges or days of operation:
- Essential diagnostic systems:
- Type of plasmas (heating configuration):
- Specific requirements on wall conditioning if any:
- External users: need a local computer account for data access: yes/no
- Any external equipment to be integrated? Provide description and integration needs:
Preferred dates and degree of flexibility
Preferred dates: (format dd-mm-yyyy)
References
[1] B. López-Miranda et al., “Investigation of the toroidal propagation of lithium injected by LIBS intoTJ-II plasmas to measure edge ion temperatura” EPS Conference Praga (2018) [2] F L Tabarés and D Tafalla. “Self-consistent Determination of the Ion Thermalization Rate at the Plasma Boundary of TJ-II by the Supersonic He Beam Diagnostic”. Nucl. Fusion 55 (2015) 013020 [3] A. Baciero et al., Rev. Sci. Instrum. 72 971 (2001) [4] I. S. Nedzelskiy, private communication