Railgun performance with a two-stage light-gas gun injector

Conference · Mon Jan 01 00:00:00 EST 1990

OSTI ID:6875072

Hawke, R S; Susoeff, A R ^[1]; Asay, J R; Ang, J A; Hall, C A; Konrad, C H; Wellman, G W ^[2]; Hickman, R J; Heath, W A; Martinez, J R ^[3]; Sauve, J L; Vasey, A R ^[4]; Shahinpoor, M ^[5]

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1. Lawrence Livermore National Lab., CA (USA)
2. Sandia National Labs., Albuquerque, NM (USA)
3. Ktech Corp., Albuquerque, NM (USA)
4. EG and G, Inc., Albuquerque, NM (USA)
5. New Mexico Univ., Albuquerque, NM (USA)

This paper summarizes the results obtained with the HELEOS railgun which uses a two-stage light-gas gun (2SLGG) as an injector. The high velocity 2SLGG injector pre-accelerates projectiles up to {approximately}7 km/s. The high injection velocity reduces the exposure duration of the railgun barrel to the passing high temperature plasma armature, thereby reducing the ablation and subsequent armature growth. The 2SLGG also provides a column of cool, high pressure hydrogen gas to insulate the rails behind the projectile, thereby eliminating restrike. A means to form an armature behind the injected projectile has been developed. In preliminary tests, the third stage railgun has successfully increased the projectile velocity by 1.35 km/s. Extensive diagnostics have been used to determine the behavior of the armature and track the launcher's performance. In some cases, velocity increases in the railgun section have been achieved, which are in close agreement with theoretical predictions, whereas in other experiments deviations from theoretical have been observed. The reasons for and implications of these results are addressed. Recent tests are reported. 17 refs., 7 figs., 1 tab.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• Sponsoring Organization: DOE/DP
• DOE Contract Number: W-7405-ENG-48; AC04-76DP00789
• OSTI ID: 6875072
• Report Number(s): UCRL-101932-Rev.1; CONF-9004136-9-Rev.; ON: DE90016211
• Resource Relation: Conference: 5. IEEE symposium on electromagnetic launch technology, Destin, FL (USA), 1-5 Apr 1990
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
PROJECTILES
LAUNCHING
RAILGUN ACCELERATORS
PERFORMANCE TESTING
ABLATION
BOUNDARY LAYERS
COMPARATIVE EVALUATIONS
CURRENT DENSITY
DRAG
ELECTRIC POTENTIAL
ELECTROMAGNETIC FIELDS
EVAPORATION
MEASURING METHODS
PLASMA
PRESSURE EFFECTS
STABILITY
SURFACE PROPERTIES
VELOCITY
ACCELERATORS
LAYERS
PHASE TRANSFORMATIONS
TESTING
420200* - Engineering- Facilities
Equipment
& Techniques