Speaker
Description
The Zero Power Tuneable Optics (ZEPTO) project at STFC Daresbury Laboratory has developed several prototype permanent magnet quadrupoles with tuneable magnetic field gradient. These magnets have the largest tuning range so far demonstrated for permanent magnet quadrupoles, and operate by moving permanent magnet blocks relative to fixed steel structures that define the flux path, allowing gradient to be adjusted whilst homogeneity remains defined by the steel shape. However, maintaining stable field homogeneity and magnetic axis position during adjustment remains a challenge that requires extremely high precision in manufacture and assembly to achieve. Based on lessons learned from the latest ZEPTO prototype, which operated for 2 years installed on Diamond Light Source, we have developed a fourth prototype which will be installed on the CLARA linear accelerator at Daresbury Laboratory.
This new prototype contains two key developments over the previous prototype to allow the difficulties in manufacturing and assembly precision to be overcome. In the event that magnetic measurements reveal poor magnet harmonics or magnetic axis shift as a function of gradient adjustment, these can now be corrected in the new prototype without re-assembling the magnet or re-machining components. We show by 3D FEA that by the addition of magnetic steel shims in defined patterns we can correct for excessive higher order field components, and that by removing rods of material from the yoke in pre-defined patterns we can tune the level of field saturation in one half of the magnet to correct magnetic axis movement. This represents the next step into bringing this technology into direct competition with electromagnets in terms of convenience and reliability.
| Presenting Author | Alex Bainbridge |
|---|---|
| Is the Presenting Author a PhD Student or Early Career Scientist ? | No |
| Area of research | Accelerator technology (including magnets) |