Results from recent hydrogen pellet acceleration studies with a 2-m railgun
A new 3.2-mm-diameter, two-stage, fuseless, plasma-arc-driven electromagnetic railgun has been designed, constructed, and successfully operated to achieve a record velocity of 2.67 km/s({sup b}) for 3.2 mmD {times} 4 mmL solid hydrogen pellet. The first stage of this hydrogen pellet injector is a combination of a hydrogen pellet generator and a gas fun. The second stage is a 2-m-long railgun which serves as a booster accelerator. The gas fun accelerates a frozen hydrogen pellet to a medium velocity and injects it into the railgun through a perforated coupling piece, which also serves a pressure-relieving mechanism. An electrical breakdown of the propellant gas, which has followed the pellet from the gas fun into the railgun, forms a conducting plasma-arc armature immediately behind the pellet allowing for fuseless operation of the railgun. Study of the pressure profile and the behavior of the plasma-arc armature inside the railgun bore led to elimination of spurious arcing, which prevents operation of the railgun at high voltages (and, therefore, at high currents). A timing circuit that can automatically measure the pellet input velocity and allows for accurate control of arc initiation behind the pellet helps prevent pellet disintegration and mistriggering of the arc initiation circuit. Results from the recent cryogenic operation of the two-stage pellet acceleration system are reported. 11 refs., 2 figs., 1 tab.
- Research Organization:
- Illinois Univ., Urbana, IL (USA). Fusion Technology Lab.
- Sponsoring Organization:
- DOE/ER
- DOE Contract Number:
- FG02-84ER52111
- OSTI ID:
- 6996889
- Report Number(s):
- CONF-891007-118; ON: DE90008773
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
700205* -- Fusion Power Plant Technology-- Fuel
Heating
& Injection Systems
ACCELERATORS
BREAKDOWN
CAMERAS
CLOSED PLASMA DEVICES
CRYOGENICS
DESIGN
ELEMENTS
FUEL PELLETS
HYDROGEN
MEASURING INSTRUMENTS
NONMETALS
PELLET INJECTION
PELLETS
PLASMA DIAGNOSTICS
RADIATION DETECTORS
RAILGUN ACCELERATORS
STREAK CAMERAS
THERMONUCLEAR DEVICES
TOKAMAK DEVICES