Evaluation of two proposed improvements to the gradient B drift geometry
Abstract
The magnetic fields in various gradient transport schemes for electron pulse compression were calculated. Infinite wired fields were found to be correct regardless of the entrance foil cone angle. The fields outside the transport volumes are zero. The electron drift rates and injection criteria were extended and verified numerically. The injection criteria are valid for any entrance foil cone half angle between 0 and (LC OMEGA)/2 radians. Finally, two improvements to the basic transport scheme in the references were evaluated. The conical entrance foil idea seems to be the best way of increasing warm beam electron injection efficiencies. this idea would not work for a cold beam because the cold beam electrons' angles, (-), would be less than the critical angle needed for injection. The cold beam injection efficiency, however, can be improved by the use of double entrance foils with a reversed current. The double entrance foil idea with a forward current appears to be unsatisfactory because beam radii increase greatly. The main disadvantage of these ideas is increased complexity.
- Publication:
-
Unknown
- Pub Date:
- July 1981
- Bibcode:
- 1981etpi.rept.....B
- Keywords:
-
- Beam Currents;
- Computerized Simulation;
- Drift Rate;
- Electron Acceleration;
- Relativistic Electron Beams;
- Beam Injection;
- Foils (Materials);
- Linear Accelerators;
- Magnetic Fields;
- Pulse Compression;
- Radiation Transport;
- Space Charge;
- Atomic and Molecular Physics