Creedon Machine

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Definition:                           

Equations

Parameters

Diagram

 

 

 

Calculate Machine Attributes:              top

Parameter       

Value

Units

Special Values 

Inputs:

ZS (Source Line Impedance) [Ω] 
VS (Source Voltage) [MV]   
  ZVac (MITL Vacuum Impedance) [Ω]   
ZD (Diode Impedance) [Ω]  Optional Input for "With Radiographic Diode" outputs, only affects output when less than self-limited ZB
           
         
           

Outputs:

Running Self Limited

       
VL (Load Voltage) [MV]    
  IA (Anode Current) [kA]     
  Zop (MITL Operating Impedance) [Ω]     
  ZB (Bound Impedance) [Ω]     
  IB (Bound Current) [kA]    
  IS (Sheath Current) [kA]    
  gm (Gamma Minimum)      
           
 

With Radiographic Diode: "Retrapping" Solution

       
  VL (Load Voltage) [MV]    
  IA (Anode Current) [kA]    
  Zop (MITL Operating Impedance) [Ω]     
  ZB (Bound Impedance) [Ω]     
  IB (Bound Current) [kA]    
  IS (Sheath Current) [kA]    
  gm (Gamma Sheath)      
           
 

With Radiographic Diode:  Steady State Solution

       
  VL (Load Voltage) [MV]    
  IA (Anode Current) [kA]    
  Zop (MITL Operating Impedance) [Ω]     
  ZB (Bound Impedance) [Ω]     
  IB (Bound Current) [kA]    
  IS (Sheath Current) [kA]    
  gm (Gamma Sheath)      
           

 

Output Format:                                                        top

Select Format: Scientific Engineering Fixed

 

Notes:                                                                       top

bulletUpon further reflection, there are two solutions of interest...  These are the "re-trapping" solution and the steady state solution.  The "re-trapping" solution is the result when the forward wave first hits the load but before the retrapping wave goes back to the machine.  In a sense, this is the result before the generator is aware of the actual load.  Because the retrapping wave velocity is often very slow, this result may be the most useful for actual generators.  This result does not lie on the load line.  Eventually, after waves propagate back and forth between the generator and the load, the "steady state" solution will be reached.  This result does lie on the load line.  27Aug07
bulletFixed a bug regarding "With Radiographic Diode" results where answer did not lie on the load line 11May07
bulletIt is assumed that the source transmission line transit time is much longer than the electrical pulse. 
bulletSolver assumes no reflection from self-limited load and MITL has same effective impedance as load.  (I think this is usually a pretty good assumption, although not 100% accurate).
bulletUndermatched solver assumes a forward going wave in MITL with same voltage as in self-limited case and an MITL impedance equal to the vacuum impedance.  (This is probably only a good assumption when very undermatched.)
bulletSources: 
bulletPrivate communications with Dave L. Johnson and Vern Bailey of Titan, PSD.
bulletVern Bailey's Beams2004 paper.
bulletJ. M. Creedon,  Appl. Phys. 48, 1070 (1977).
bulletCreedon JM. J Appl Phys 1975; 46: 2946-2955.

 

Copyright 2006  Raymond J. Allen