Abstracts Brochure - CERN

THPCH — Poster Session 29-Jun-06 16:00 - 18:00
65 MEV Neutron Irradiation of ND-FE-B Permanent Magnet
Rare-earth permanent magnets are now playing
a major role in accelerator technology,
from the development of beam transport systems
magnets to their extensive use in syn-
X.-M. Maréchal, T. Bizen (JASRI/SPring-8) Y. Asano (JAEA/
SPring-8) H. Kitamura (RIKEN Spring-8 Harima)
chrotron radiation sources and free electron lasers. Unfortunately, operating in a high radiation environment, rareearth
permanent magnets are subject to demagnetization caused by direct and scattered radiation. The lifetime of
these components is therefore a major issue: as a result, the number of studies to clarify the demagnetization mechanism
or to test materials of interest for a particular application under specific conditions of irradiation has increased
in recent years. However, so far, neutron irradiation experiments have been mainly carried out with reactors, were
neutrons have a wide, but mainly low, energy spectrum. We present here the results obtained at the TIARA facility
of the Japan Atomic Energy Research Institute, a spalliation source of mono highly energetic neutrons. Four types of
Nd-Fe-B permanent magnets (Neomax TM 35EH, 32AH, 27VH and 44H) representing a wide range of characteristics
(remanence and coervicity) have been studied.
Design of a Permanent Magnet Quadrupole
In this paper we present a new design for a
permanent magnet-based quadrupole. The
performances are analysed and compared to
other similar systems. Several sources of er-
X.-M. Maréchal (JASRI/SPring-8) T. Shintake (RIKEN Spring-8
Harima)
rors such as misalignment and demagnetization due to irradiation have been analysed.
Design of a Pulsed 2.5 MeV High Charge Electron Photo-injector
The design of an electron beam experiment
DEINOS has been carried out at Bruyeres le J.-L. Lemaire (CEA)
Chatel research center. This experiment is
intended to demonstrate i)the faisability of a multi bunch high charge production source from a photocathode
illuminated by a pulsed UV laser, ii)the quality of the beam composed of 120 ps duration electron bunches (energy
stability, emittance). Successive trains of 20 bunches (micro-pulses), each bunch carrying a 100 nC charge would be
extracted from the photocathode and accelerated in a DC electron gun to an energy of 2.5 MeV. The gun consists of
a DC acceleration gap and a photocathode remote handling chamber. Development of CsTe photocathodes for this
application is also pursued. The resulting high brightness electron gun injector will be the first stage of a variable
energy electron machine dedicated to the development and calibration of diagnostics for imaging applications. Details
of the design will be reported along with simulation results for beam generation, acceleration and final focusing.
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THPCH135
THPCH136
THPCH138