Thesis outline
From Ciswikidb
Contents
- 1 Introduction
- 2 Generation of the magnetized electron beam
- 3 Beam dynamics
- 4 Space charge effect
- 5 Simulations on the magnetized electron beam
- 6 Characterization of the magnetized beam
- 7 Experiments and numerical simulations of the space charge dominated magnetized beam
- 8 Redesigning and performance of the photogun
- 9 Repeated experimental and numerical simulations results of the space charge dominated magnetized beam with the new photogun
- 10 Summary and Conclusions
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
- Existing electrostatic design
- Modified electrostatic design
- Polishing and gun assembly
- High voltage conditioning