Electron Recycling Spectrometer

The Development of an Ultra High-Energy Resolution Electron Source
for an Electron-Molecules Collisions Facility.

A novel electrostatic storage ring - the “Electron Recycling Spectrometer” (ERS) - has been designed in collaboration with Hammond (UWA, Australia) and Read (Manchester, UK); the prototype has been constructed at Windsor.

The ERS, shown schematically in Fig 1 consists of two precision-made hemispherical energy analysers (HDAs) separated by two cylindrically symmetric electron lens stacks. The small length of the ~65 cm orbital path and its control via only electric fields makes this a novel approach to store low energy charged particle beams. The ERS has been demonstrated using electrons [1], but can be adapted for any charged particle: spin polarised electrons, positrons, exotic atomic and molecular ions. From our theoretical studies [2] the ERS can operate in a variety of modes which are inherently stable (or pseudo-stable) and therefore suitable for charge particle storage. It could also have a time dependent energy resolution, due to chromatic aberrations. The flexibility in the ERS’ modes of operation is an exciting prospect for novel experiments in collision physics. In [1] we show that a 50 ns wide electron pulse injected into the ERS can undergo ~1000 orbits, corresponding to an electron of mean energy ~20 eV travelling over 650 m!

[1] Tessier et al, Phys Rev Letts 99 (2007) 253201
[2] Hammond et al, New J Phys 11 ( 2009) 043033

Figure 1: (a) Schematic of the Electron Recycling Spectrometer. See [1,2]) for details.
(b) An image from the CPO (Charge Particle Optics) Program showing the electron optical simulation of the ERS system.

ERS Simulations (see [2] for details)

Various Photos

Grad Student Mike Niu by the ERS Chamber.
	The Electron Recycling Spectrometer(ERS)

Gold-plated OFC components

ERS under construction