87
An Ultra‑Low‑Emittance,
L‑Band, Flat‑Beam PWT Photoinjector--DULY Research Inc.,
Dr. David U.L. Yu, Principal Investigator, davidyu@pacbell.net
Dr. David Yu, Business Official, davidyu@pacbell.net
DOE Grant No. DE‑FG02‑06ER84460
Amount: $650,000
The International Linear Collider (ILC) needs a polarized
electron source capable of producing an electron beam with 85% polarization,
when illuminated by a circularly polarized laser. The current design of the ILC polarized
electron source is based on a DC gun and a subharmonic buncher, followed
downstream by a large, expensive damping ring.
This project will develop an alternative approach in which an L-band,
normal-conducting, polarized electron gun of the Plane-Wave-Transformer (PWT)
design is used to meet ILC specifications.
In Phase I, detailed numerical simulations and tradeoff studies – based
on vacuum, RF, magnet, beam dynamics, thermal hydraulic, and mechanical
considerations – were used to identify a baseline design for the L-band, PWT
photoinjector. Phase II will entail the
detailed mechanical design of a 1.3 GHz, 2-cell PWT gun, followed by the
fabrication and assembly of the entire system.
Tests will be performed at the Fermi National Accelerator Laboratory in
order to demonstrate: (1) the generation
of a beam with the targeted polarization and an ultra low vertical emittance, and (2) the survivability of the GaAs
photocathode needed to produce such a beam.
Commercial Applications and Other Benefits as described by the awardee: The use of an L-band PWT gun as a viable electron source
could potentially save ~$100M in ILC construction costs by eliminating the
complicated and expensive damping ring.
In other applications, the PWT gun could be used as a high brightness
electron injector for linear accelerators, synchrotrons, FELs,
and other light sources. In combination
with a high-intensity laser, the PWT gun could serve as a