Abstracts Brochure - CERN

MOPCH — Poster Session 26-Jun-06 16:00 - 18:00
On a Skeleton CASSINI Ovales Current Undulator
A new undulator structure for free electron
lasers was presented. Current skeleton
CASSINI ovals produced magnetic fields
which are spatially periodic. The current
structure was in the shape of stacks of mod-
A.M. Mihalache, V.I.R. Niculescu (INFLPR) V. Babin (INOE) F.
Scarlat (Valahia University, Faculty of Sciences) C. Stancu (Bucharest
University, Faculty of Physics)
ified CASSINI ovals. The current has alternating directions. The magnetic field components for each wire present
C2 symmetry. CASSINI undulator transverse cross-section* was approximated by polygons. In cartesian coordinates
the Biot-Savart law was analytically evaluated. The magnetic field was mainly transversal and easily adjusted with
the current. The versatility of this structure introduces a new type of two beams longitudinal undulator or wiggler
design for transverse moments.
*Cassini curve; C. Mihu, I.P. Iambor-1989.
Preliminary Physics Design for an IR FEL Proposal
The present paper is a description of the design
requirements, methods and results for
an IR FEL driven by the 7 MeV Linac of the
National Institute for Laser, Plasma and Ra-
F. Scarlat, A.M. Mihalache, V.I.R. Niculescu, M. Oane, C. Oproiu
(INFLPR)
diation Physics. Design issues and parameter optimization for the above FEL in the SASE operation mode are
approached.
Photocathode Roughness Impact on Photogun Beam Characteristics
Photocathode surface roughness has an impact
on photoelectron yield, bunch duration, T.V. Gorlov (MEPhI) A.M. Tron (LPI)
beam emittance at the exit of femtosecond
photogun with an accelerating field that is considered in assumption of quasi-stationary one in the paper. The main
problem in investigating the impact is determination of the field near the surface, statistical properties of which are
defined through rms values of deviation and slope in profile line of the surface roughness. Developed and created
code allows determining the field with relative rms error not worse than 0.001%. The results of the investigation for
rms values of roughness and its slope within respectively 500. . .0 nm and 20. . .0 degrees are presented and discussed.
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