Implementation of a Liquid Metal Dropper in the LTX- β Evaporators

The Li loading of the current LTX-β Mark-II evaporators is done in air which increases the Li oxidation and impurity contamination during the transfer. Previous TPD studies [1] showed co-desorption of H, O, N, and C-containing species with Li in the TPD peak envelope, which indicates there is impurity co- deposition during Li evaporations. Furthermore, current evaporators can hold approximately 5 g of Li and require frequent venting to reload Li. For this reason, a liquid metal dropper will be implemented in the LTX- β evaporators with two main purposes: 1) reduce the impurity contamination of Li during loading and thus decrease the impurity co-deposition with Li on the PFCs, and 2) allow for multiple refills of the evaporators using the LM dropper. The LM dropper will have the capability of loading >30g of Li, which will enable more than 5 refills of the evaporators without venting. The dropper will be designed based on

Penn State’s dropper design [2]. This upgrade will allow cleaner, shot-to-shot lithium evaporations in LTX- β.