UCLA Permanent Magnet Quadrupole
PMQ RADIA Simulation
UCLA PMQ Final Focusing System
UCLA Permanent Magnet Quadrupole
PMQ RADIA Simulation
UCLA PMQ Final Focusing System
The final focus system for the Thomson X-ray scattering experiment termed PLEIADES (Picosecond Laser-Electron InterAction for Dynamic Evaluation of Structures) at LLNL demands ultra-high field gradient quadrupoles in order to focus electron beams to 10-20µm spot sizes. The final focus scheme is based on an ultra-high gradient of 560T/m quadrupole which employs the Halbach 16-piece, permanent magnet design. Use of this optimized geometry, NdFeB material, and a small bore of 5 mm allows the desired field gradient, and a few cm focal length, to be achieved. The adjustability of the focusing system is obtained by changing the relative longitudinal positions of sub-component focusing and defocusing magnets on precision movers.
| Parameters | Value |
| Magnetic material | NdFeB |
| Remnant field [kG] | 12 |
| Inner radius [mm] | 2.5 |
| Outer radius [mm] | 7.5 |
| Length [mm] | 10.0 |
| Field Gradient [T/m] |
560.0 |
| Magnetic effective length [mm] | 10.35 |
| Integrated magnetic field strength [T] | 6.0 |
| Geometry |
|
[1] RADIA page