Sep 20 – 24, 2021
America/Vancouver timezone

The H$^-$ Multiaperture Source NIO1: Conditioning and First Cesiations

Not scheduled
20m
Poster Ion sources for fusion Poster Session 1

Speakers

Marco Cavenago (INFN-LNL) Marco Barbisan (Consorzio RFX)

Description

Observation of a transient, in Cs-free regime and long term NIO1 operation, led to the development of stabilization techniques, including conditioning (with oxygen or other gases, as argon, nitrogen, and xenon), interleaved with days of use of H$_2$ as a process gas. Stabilization of transients gave more H$^-$ current and less plasma luminosity. After installation of a cesium oven, some additional increase (up to a factor of 2 reaching an average about 50 A$/$m$^2$) of current was observed, but effect saturates at a moderate oven reservoir temperature. Obtained beam optics will be compared with theoretical expectation and old results in the Cs-free regime in similar conditions (as source voltage, often set to 11 kV). In both regimes, central beamlet apparent density is larger, possibly because a bias plate BP mask reduces side ones. Further improvements including long term conditioning of oven, modification of BP mask and of Cs pipe nozzle (with supporting simulations) are discussed.

E-mail for contact person marco.cavenago@lnl.infn.it
Funding Information Euratom (Eurofusion, grant no. 633503); INFN-E; INFN-CSN5 (experiments Plasma4beam and Ion2neutral)

Primary authors

Marco Cavenago (INFN-LNL) Marco Barbisan (Consorzio RFX) Rita Sabrina Delogu (Consorzio RFX) Antonio Pimazzoni (Consorzio RFX) Carlo Poggi (Consorzio RFX) Margherita Ugoletti (University of Padua) Vincenzo Variale (INFN - Bari)

Co-authors

Vanni Antoni (Consorzio RFX, e CNR) Dr Diego Ravarotto (Consorzio RFX) Gianluigi Serianni (Consorzio RFX) Carlo Baltador (CNR - Consorzio RFX) Luca Franchin (Consorzio RFX) Denis Martini (INFN-LNL) Moreno Maniero (Consorzio RFX) Alessandro Minarello (INFN-LNL) Roberto Rizzieri (Consorzio RFX) Livio Romanato (Consorzio RFX) Federico Rossetto (Consorzio RFX) Francesco Taccogna (CNR)

Presentation materials