1. Field Analysis in four different rf gun structures
1. 2d-gun structure
2. 3d-gun structure without racetrack and laser ports
3. 3d-gun structure with racetrack but without laser ports
4. 3d-gun structure with racetrack and laser ports
L.Xiao and Z.Li

2. 1. 2d-gun structure
L.Xiao and Z.Li

3. 2. 3d-gun structure without racetrack and laser ports
βr/mm
maxβr=5.55e-3/mm
L.Xiao and Z.Li

4. 3. 3d-gun structure with racetrack but without laser ports
βr/mm d b1 b1
L.Xiao and Z.Li

5. βr/mm
L.Xiao and Z.Li

6. 4. 3d-gun structure with racetrack and laser ports
βr/mm
The racetrack corrects only the quad in the full cell.
The skew quad effect in the half cell due to laser ports needs to be evaluated, racetrack can be added to the half cell if necessary.
L.Xiao and Z.Li

7. Summary: 2d-gun structure: no quadruple fields;
3d-gun structure without racetrack and laser ports: maxβr=5.55e-3/mm;
3d-gun structure with racetrack and without laser ports: maxβr=3.18e-5/mm;
3d-gun cavity with racetrack and laser ports: maxβr=2.98e-4/mm. d b1 b1
L.Xiao and Z.Li