Determination of current distribution in EM gun armature by least squares fitting of BSi (smallinduction) coil voltage
Abstract
The electromagnetic (EM) plasma railgun current distribution was determined by fitting (using the method of least squares) the voltage induced on small induction (BSi) coils to a derived function model. The voltage function model was derived using the BiotSavart equation. The model was derived assuming that the current flowed in sheets perpendicular to the rails. The sheets of currents varied in time and in the rail direction but were assumed to be constant (at a given time) perpendicular to the bore direction. The plasma current distribution in the bore direction, the initial length, and expansion characteristics of the plasma were determined from BSi coil voltage measurements taken at short time increments. Fitted parameters correlate well with measurements taken by other sensors.
 Publication:

IEEE Transactions on Plasma Science
 Pub Date:
 June 1988
 DOI:
 10.1109/27.3842
 Bibcode:
 1988ITPS...16..352C
 Keywords:

 Armatures;
 Current Distribution;
 Electromagnetic Acceleration;
 Least Squares Method;
 Plasma Currents;
 Railgun Accelerators;
 Biot Method;
 Current Sheets;
 Electric Potential;
 Magnetic Coils;
 Plasma Dynamics;
 Electronics and Electrical Engineering