Abstracts Brochure - CERN

WEPLS047
WEPLS048
WEPLS049
28-Jun-06 16:00 - 18:00 WEPLS — Poster Session
3-1/2 Cell Superconducting RF Gun Simulations
C.D. Beard, P.A. McIntosh, J.H.P. Rogers (CCLRC/DL/ASTeC) A.
Arnold, D. Janssen, F. Staufenbiel, J. Teichert (FZR)
346
A 3-1/2 cell superconducting RF photocathode
gun is being developed at
Forschungszentrum Rossendorf to produce
a high peak current, low emittance electron
beam. This technology is essential to the realisation of many large scale facilities. The gun is designed for CW
operation mode with 1 mA current and 9.5 MeV electron energy, and it will be installed at the ELBE superconducting
electron linear accelerator. The gun will have a 3-1/2 cell niobium cavity operating at 1.3 GHz. The cavity consists
of three cells with TESLA geometry and a specially designed half-cell in which the photocathode will be placed.
Typical ERL-based projects require ∼100 mA average current, and therefore suitable upgrade paths are required.
Simulations have been carried out to evaluate the design and to determine suitable upgrades for higher current
operation. Simulations of alternative cathode surface shapes are presented. Several couplers have been identified
that can provide higher power to the cavity, whose integration and suitability has been verified. All the investigations
that have identified possible solutions to higher current operation are discussed in this report.
Development of a Positron Production Target for the ILC Positron Source
I.R. Bailey, I.R. Bailey, J.B. Dainton, D.J. Scott (Cockcroft Institute)
V. Bharadwaj, J. Sheppard (SLAC) P. Cooke, P. Sutcliffe (Liverpool
University, Science Faculty) J.G. Gronberg, W. Stein (LLNL)
The future International Linear Collider
(ILC) will require of order 10 14 positrons per
second to fulfil its luminosity requirements.
The current baseline design produces this
unprecedented flux of positrons using an un-
dulator-based source. In this concept, a collimated beam of 10MeV photons produced from the action of an undulator
on the main electron beam of the ILC is incident on a conversion target. Positrons produced in the resulting electromagnetic
shower can then be captured, accelerated and injected into a damping ring. The international community
is pursuing several alternative technologies to develop a target capable of long-term operation in the intense photon
beam. In the design being developed jointly by the Cockcroft Institute, LLNL and SLAC, a thin (0.4 radiation length)
water-cooled Titanium alloy target wheel of diameter 4m is rotated at approximately 1000rpm to spread the incident
power of each pulse over a wide area. We present the latest target design, report on the status of the target prototypes
and computer models, and review the interplay between the target technology, capture optics, photon collimator and
remote-handling systems.
The Design of a Hybrid Photoinjector for High Brightness Beam Applications
D. Alesini, M. Ferrario, V. Fusco, B. Spataro (INFN/LNF) L. Ficcadenti,
A. Mostacci, L. Palumbo (Rome University La Sapienza) B.
O’Shea, J.B. Rosenzweig, G. Travish (UCLA)
In this paper, we illustrate the electromagnetic
and beam dynamics design procedure
of a new class of photoinjector, a hybrid
standing/traveling wave structure. In this
device a standing wave RF gun section is in-
tegrated with a downstream traveling wave structure through a coupling cell that feeds simultaneously the two
sections. We discuss the advantages in RF and beam performance of the hybrid photoinjector compared to conventional
systems. The electromagnetic design has been performed using the 2D and 3D electromagnetic codes Superfish
and HFSS. Results of beam dynamics simulations in different operating conditions are also discussed.