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Title: The SPIRAL 2 Project

Abstract

The project of an important new extension of the GANIL facility - SPIRAL 2 - is shortly presented. The physics case of the facility is based on the use of high intensity stable and radioactive beams. Expected performances and main technical parameters of the facility as well as planned new experimental areas and detectors are shortly described.

Authors:
 [1]
  1. Grand Accelerateur d'Ions Lourds - GANIL, CEA/DSM-CNRS/IN2P3, BP 55027, 14076 Caen Cedex (France)
Publication Date:
OSTI Identifier:
21056785
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 891; Journal Issue: 1; Conference: 6. Symposium on nuclear physics, Tours (France), 5-8 Sep 2006; Other Information: DOI: 10.1063/1.2713504; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA). Collaboration: SPIRAL 2 Project Group
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BEAM PRODUCTION; GANIL CYCLOTRON; HEAVY ION REACTIONS; PERFORMANCE; RADIATION DETECTORS; RADIOACTIVE ION BEAMS

Citation Formats

Lewitowicz, Marek. The SPIRAL 2 Project. United States: N. p., 2007. Web. doi:10.1063/1.2713504.
Lewitowicz, Marek. The SPIRAL 2 Project. United States. doi:10.1063/1.2713504.
Lewitowicz, Marek. Mon . "The SPIRAL 2 Project". United States. doi:10.1063/1.2713504.
@article{osti_21056785,
title = {The SPIRAL 2 Project},
author = {Lewitowicz, Marek},
abstractNote = {The project of an important new extension of the GANIL facility - SPIRAL 2 - is shortly presented. The physics case of the facility is based on the use of high intensity stable and radioactive beams. Expected performances and main technical parameters of the facility as well as planned new experimental areas and detectors are shortly described.},
doi = {10.1063/1.2713504},
journal = {AIP Conference Proceedings},
number = 1,
volume = 891,
place = {United States},
year = {Mon Feb 26 00:00:00 EST 2007},
month = {Mon Feb 26 00:00:00 EST 2007}
}
  • Development of new radioactive beams, and thus of new target ion sources (TISs) for isotope-separator-on-line production systems are in progress at GANIL for the SPIRAL 2 project. The efficiency and time response measurements of each step in the production process are crucial to predict and maximize the available yields, in particular, for short lived isotopes. This paper presents a method for measuring these quantities that makes use of a stable alkali chopped beam of controlled intensity. This method was applied to surface ionization source test for high efficiency. Results of recent experiments are presented that include ionization efficiency measurements formore » Cs, Rb, K, Na, and Li with a graphite and rhenium ionizer and dwell time of these alkalis on graphite. The results enabled to design a first surface ionization source prototype which will be installed in the SPIRAL 2 TIS.« less
  • The SPIRAL 2 facility, currently under construction, will provide either stable or radioactive beams at high intensity. In addition to the high intensity of stable beams, high charge states must be produced by the ion source to fulfill the RFQ LINAC injection requirements: Q/A = 1/3 at 60 kV ion source extraction voltage. Excepting deuterons and hydrogen, most of the stable beam requests concern metallic elements. The existing 18 GHz electron cyclotron resonance ion source (ECRIS) Phoenix V2 designed at LPSC Grenoble has been used for the tests and will be the source for the SPIRAL 2 commissioning. The testsmore » performed at LPSC for calcium ({sup 40}Ca{sup 14+} and {sup 40}Ca{sup 16+}), nickel ({sup 58}Ni{sup 19+}), and sulfur ({sup 32}S{sup 11+}) are described and discussed. Due to the very high charge states required, the oven method has been chosen. An intensity of 1 pμA has been reached for those elements. The performance and the beam stability have been studied using different buffer gases, and some ionization efficiency preliminary results are given.« less
  • Magnetic hysteresis loops were measured on spiral-grown Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub y} (Bi-2212) crystals. An anomalous peak effect at a magnetic field of 1000{endash}2000 Oe was observed both in high-T{sub c} (86 K) and oxygen underdoped (T{sub c}=76 K) spiral-grown crystals between 20 and 40 K. The peak effect was observed to be stronger than that induced by oxygen vacancies, defect dislocation networks reported in Bi-2212 crystals. Further, the anomalous peak almost completely disappeared after removing growth spiral patterns from the crystal surface. Edge barriers associated with the growth spirals are suggested to be responsible for the strong peak effectmore » for the spiral-grown Bi-2212 crystals and not oxygen vacancies or screw dislocations {copyright} {ital 1997} {ital The American Physical Society}« less
  • Neutron-diffraction and inelastic-scattering experiments are used to investigate in detail the field dependence of the magnetic structure and low-energy spin-wave spectrum of the Dzyaloshinskii-Moriya helimagnet Ba{sub 2}CuGe{sub 2}O{sub 7}. The results suggest that the previously proposed model for the magnetism of this compound (an ideal sinusoidal spin spiral, stabilized by isotropic exchange and Dzyaloshinskii-Moriya interactions) needs to be refined. Both recent and previously published data can be quantitatively explained by taking into account the Kaplan-Shekhtman-Entin-Wohlman-Aharony term, a special magnetic anisotropy term that was predicted to always accompany Dzyaloshinskii-Moriya interactions in insulators. {copyright} {ital 1999} {ital The American Physical Society}
  • The quasi-two-dimensional square-lattice antiferromagnet Ba{sub 2}CuGe{sub 2}O{sub 7} was studied by neutron scattering and bulk magnetic techniques. An incommensurate magnetic spiral structure with the propagation vector (1+{zeta},1+{zeta},0) ({zeta}=0.027) was observed below {ital T}{sub {ital N}}=3.26 K. Magnetic ordering occurs with a two-dimensional-like critical exponent {beta}{approx_equal}0.15. The spin dynamics can be adequately described by conventional spin-wave theory with two exchange constants: nearest-neighbor in-plane antiferromagnetic coupling {ital J}{sub 1}{approx_equal}0.48 meV and interplane ferromagnetic interaction {ital J}{sub {perpendicular}}{approx_equal}0.013 meV. This set of exchange parameters apparently fails to explain the spiral order. The noncentrosymmetric crystal structure suggests that the incommensurate phase may be themore » result of a Dzyaloshinskii-Moriya instability of the N{acute e}el ground state. {copyright} {ital 1996 The American Physical Society.}« less