@inproceedings{1ff6e4857d8d4cc59bddec9cbfdda700,
title = "Cryogenic pellet production developments for long-pulse plasma operation",
abstract = "Long pulse plasma operation on large magnetic fusion devices require multiple forms of cryogenically formed pellets for plasma fueling, on-demand edge localized mode (ELM) triggering, radiative cooling of the divertor, and impurity transport studies. The solid deuterium fueling and ELM triggering pellets can be formed by extrusions created by helium cooled, twin-screw extruder based injection system that freezes deuterium in the screw section. A solenoid actuated cutter mechanism is activated to cut the pellets from the extrusion, inserting them into the barrel, and then fired by the pneumatic valve pulse of high pressure gas. Fuel pellets are injected at a rate up to 10 Hz, and ELM triggering pellets are injected at rates up to 20 Hz. The radiative cooling and impurity transport study pellets are produced by introducing impurity gas into a helium cooled section of a pipe gun where it deposits in-situ. A pneumatic valve is opened and propellant gas is released downstream where it encounters a passive punch which initially accelerates the pellet before the gas flow around the finishes the pellet acceleration. This paper discusses the various cryogenic pellet production techniques based on the twin-screw extruder, pipe gun, and pellet punch designs.",
keywords = "Elm pacing, Fueling, Pellet injection, Twin screw extruder",
author = "Meitner, {S. J.} and Baylor, {L. R.} and Combs, {S. K.} and Fehling, {D. T.} and McGill, {J. M.} and Duckworth, {R. C.} and McGinnis, {W. D.} and Rasmussen, {D. A.}",
note = "Publisher Copyright: {\textcopyright}2014 AIP Publishing LLC.; 2013 Joint Cryogenic Engineering and International Cryogenic Materials Conferences, CEC/ICMC 2013 ; Conference date: 17-06-2013 Through 21-06-2013",
year = "2014",
doi = "10.1063/1.4860881",
language = "English",
series = "AIP Conference Proceedings",
publisher = "American Institute of Physics Inc.",
pages = "1475--1482",
editor = "Susan Breon and Jennifer Marquardt and Thomas Peterson and Michael DiPirro and John Pfotenhauer and Jonathan Demko and James Fesmire and Arkadiy Klebaner and Sidney Yuan and Al Zeller and Peter Kittel and Gregory Nellis and Mark Zagarola",
booktitle = "Advances in Cryogenic Engineering - Transactions of the Cryogenic Engineering Conference - CEC, Volume 59",
}