View source for TJ-II:In situ, real time boronization of TJ-II

== Experimental campaign ==
2018 Autumn

== Proposal title ==
In situ, real time boronization of TJ-II.

== Name and affiliation of proponent 
F Tabares CIEMAT

== Details of contact person at LNF == N/A

== Description of the activity ==
Real time boronization of stellarators has been identified as an important technique for the routine operation of W7-X and activities on this are financed through the S1working package (0.5 ppy). Experiments in URAGAN 2M are presently planned by B powder droppers.

TJ-II can contribute to this task and two techniques are being developed: Injection of o-carborane hydrogen mixtures by a modified puffing valve and o-carborane dust dropper. These activates will be complemented with studies of the homogeneity of boronization by GD in He by using LIBs to monitor local deposition under several GD configurations.

While the relative proportion of B/H fuelling can be varied through the valve temperature in the mixed puffing case, the direct drop of o-carborane dust may be limited by the power available to fully ionize the injected particles. Therefore it is recommended to test this method in NBI heated discharges, on which the high plasma energy content and higher electron density may prevent the radiation collapse of the plasma core. A gradual increase of the amount of dust followed by bolometry will be applied. Furthermore, in both cases, LIBs can be used to assess the resulting degree of B coverage after the operation day.

== International or National funding project or entity ==
EuroFusion WP S1.

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 2 days
*LIBS, Bolometry, RGA
* 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)

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== References ==
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