Difference between revisions of "Thesis work"

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# Introduction  
+
==Introduction==
 
* ''Magnetized electron beam''
 
* ''Magnetized electron beam''
 
* ''Applications of the magnetized electron beam''
 
* ''Applications of the magnetized electron beam''
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# Generation of the magnetized electron beam
+
==Generation of the magnetized electron beam==
 
*''Experimental setup (DC HV gun, photocathode, cathode solenoid, RF laser, focusing solenoids, etc.)''
 
*''Experimental setup (DC HV gun, photocathode, cathode solenoid, RF laser, focusing solenoids, etc.)''
 
*''Beam diagnostics''
 
*''Beam diagnostics''
  
  
# Beam dynamics  
+
==Beam dynamics==
 
*''Beam matrix''
 
*''Beam matrix''
 
*''Phase space''
 
*''Phase space''
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# Space charge effect  
+
==Space charge effect==
 
*''Space charge effect in the magnetized beam''
 
*''Space charge effect in the magnetized beam''
  
# Simulations on the magnetized electron beam  
+
==Simulations on the magnetized electron beam==
 
*''ASTRA''
 
*''ASTRA''
 
**''Initial particle distribution''
 
**''Initial particle distribution''
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*''Post-processing (MATLAB)''
 
*''Post-processing (MATLAB)''
  
# Characterization of the magnetized beam  
+
==Characterization of the magnetized beam==
 
*''Experimental method''
 
*''Experimental method''
 
**''Beam size vs solenoid I''
 
**''Beam size vs solenoid I''
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# Experiments and numerical simulations of the space charge dominated magnetized beam  
+
==Experiments and numerical simulations of the space charge dominated magnetized beam==
 
*''Experimental methods''
 
*''Experimental methods''
 
**''Pulse energy vs extracted charge -for different magnetizations''
 
**''Pulse energy vs extracted charge -for different magnetizations''
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#Redesigning and performance of the photogun  
+
==Redesigning and performance of the photogun==
 
*''Gun designing''
 
*''Gun designing''
 
**''CST electrostatic design''
 
**''CST electrostatic design''
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#Repeated experimental and numerical simulations results of the space charge dominated magnetized beam with the new photogun ==
+
==Repeated experimental and numerical simulations results of the space charge dominated magnetized beam with the new photogun ==
  
  
#Conclusions  
+
==Conclusions==
  
  
 
[[Sajini Wijethunga | Return to Sajini Wijethunga]]
 
[[Sajini Wijethunga | Return to Sajini Wijethunga]]

Revision as of 01:03, 29 May 2020

Oral Qualifying Exam-March 2019

Annual review-May 2020

Thesis Outline

Introduction

  • Magnetized electron beam
  • Applications of the magnetized electron beam
    • Magnetized electron cooling
  • Jefferson Lab magnetized electron source for the JLEIC cooler


Generation of the magnetized electron beam

  • Experimental setup (DC HV gun, photocathode, cathode solenoid, RF laser, focusing solenoids, etc.)
  • Beam diagnostics


Beam dynamics

  • Beam matrix
  • Phase space
  • Emittance (thermal, phase space, geometric)
  • Effective(drift) emittance (emittance of the magnetized beam)
  • Measuring the beam emittance


Space charge effect

  • Space charge effect in the magnetized beam

Simulations on the magnetized electron beam

  • ASTRA
    • Initial particle distribution
    • Field maps (3D E field map, 2D B field map)
    • Space charge calculation mechanism
    • Emittance
  • GPT
    • Initial particle distribution (Laser*QE image processing)
    • Field maps (3D E field map, 2D B field map)
    • Space charge calculation mechanism
    • Emittance
  • Post-processing (MATLAB)

Characterization of the magnetized beam

  • Experimental method
    • Beam size vs solenoid I
    • Rotation angle vs solenoid I
    • Emittance vs solenoid I - two different laser sizes
    • Emittance vs laser spot sizes - max solenoid current
  • ASTRA/GPT simulations (Simulation of all the above variations)
  • Conclusions (comparisons -measurements vs simulations, mismatch oscillations, negative rotation angles, etc.)


Experiments and numerical simulations of the space charge dominated magnetized beam

  • Experimental methods
    • Pulse energy vs extracted charge -for different magnetizations
    • Space charge current limitation dependence on gun high voltage - for different magnetizations
    • Space charge current limitation dependence on pulse width- for different magnetizations
    • Space charge current limitation dependence on laser spot size- for different magnetizations
  • GPT simulations
  • Conclusions (Comparison -measurements and simulations)


Redesigning and performance of the photogun

  • Gun designing
    • CST electrostatic design
    • GPT simulations implementing the new gun field map
  • Polishing and gun assembly
  • High voltage conditioning


Repeated experimental and numerical simulations results of the space charge dominated magnetized beam with the new photogun

Conclusions

Return to Sajini Wijethunga