Tests on a mock-up of the feedback controlled matching options for the ITER ICRH system

For the ICRH of ITER 20MW must be coupled to the plasma in the 40-55MHz frequency band via an array of 24 radiating shorted straps fed by four generators. The matching system must provide automatic matching control on the mean load provided by the plasma and be resilient (|Γ| < 0.2) to a wide range of fast antenna load excursions occurring in ELMy plasmas. Furthermore, good control of the current distribution in the strap array must be possible for the various heating and current drive scenarios. Two load resilient matching options have been considered for ITER: the 4 “Conjugate-T” (CT) and the 4 hybrids ones, the first being presently considered as a back-up option. Automatic control of these 2 options is presently developed, and tested for optimization on a low-powered scaled mock-up. Successful implementation of the simultaneous feedback control of 11 actuators for the matching of the 4CT and for the control of the toroidal phasing has already been achieved. The matching and the array current control of the 3dB hybrid option is provided by simultaneous feedback control of the decouplers and double stub tuners (in total 23 actuators) and is being progressively implemented. The simultaneous control of matching and antenna current has already been successfully tested on part of the array

Backbending in the N=96 isotones

The backbending in the even-even, /b N/=96 isotones can be quantitatively accounted for by the rotation-alignment of the spins of neutrons in i 13/2 orbits, as shown by comparing the aligned angular momentum and relative Routhian for the /b s/-bands in these isotones and for the i 13/2 bands in the corresponding isotopes with /b N/=97. The influence of protons on this backbending situation is shown to be indirect, acting through a change of the nuclear deformation which yields a change of the moment of inertia of the g.s. band and of the non-rigid character of the rotation. The experimental data on the /b N /=96 and 97 isotones are in reasonable agreement with cranking model calculations. Possible reasons for the inhibition of backbending in the h9/2 proton bands in the odd-/b Z/, /b N/=96 isotones, all related to a change of deformation, are presented.Anglai

10. Les outils d’aide à la décision

L'eau constitue un système complexe formé de la ressource elle-même, des écosystèmes qui l'utilisent et qui l'abritent et des usages faits par la société. La gestion de ce système se heurte à la difficulté majeure de la prise en compte et de la conciliation d’intérêts, souvent peu ou pas compatibles. Formaliser les enjeux et les valeurs La conciliation de ces intérêts a été pendant longtemps régie par une vision utilitariste et des notions d'intérêt général, parmi lesquelles figurent la produ..

Results of the implementation on a mock-up of the full 3dB hybrid matching option of the ITER ICRH system

Each of the two ICRH antennas for ITER must couple 20MW to the plasma in the 40-55MHz band via an array of 24 radiating shorted straps fed by four generators. The matching system must provide automatic matching control on the mean load provided by the plasma and be resilient (|Γ| < 0.2) to a wide range of fast antenna load excursions occurring in ELMy plasmas. Furthermore, good control of the current distribution in the strap array must be possible for the various heating and current drive scenarios. Two load resilient matching options have been considered for ITER: the 4 “Conjugate-T” (CT) and the 4 hybrids ones, the first being presently considered as a back-up option. Automatic control of these 2 options has been developed, and tested for optimization on a low-powered scaled mock-up. Successful implementation of the simultaneous feedback control of 11 actuators for the matching of the 4CT and for the control of the toroidal phasing has already been achieved. The matching and the array current control of the 3dB hybrid option are provided by simultaneous feedback control of the decouplers and double stub tuners (in total 23 actuators) and this has also been successfully achieved for the full array. The paper discusses the circuit implementation and presents the obtained results

Energy levels of /sup 162/Er through the /sup 165/Ho(p,4n gamma )/sup 162/Er reaction

The energy levels of the nucleus /sup 162/Er have been investigated by standard on-line gamma -ray spectroscopic methods using the /sup 165/Ho(p,4n gamma )/sup 162/Er reaction. Various rotational bands have been excited up to high spins; the ground-state band up to 16/sup +/; the gamma -band up to 11/sup +/ and maybe 12/sup +/; the odd-spin members of the negative-parity octupole band up to 13/sup -/; and a new band, with levels of spins 4, 6, 8, 10 and 12, which could be the even-spin part of the negative-parity octupole band. The results are compared with various theoretical models. The absolute cross sections for the /sup 165/Ho(p,/b x/n)/sup 166-x/Er reactions between /b E //sub p/=30 and 51 MeV have also been measured for /b x/=2 to 6.Anglai

Experimental evidence for low-spin members of `upper' bands in /sup 156/Dy [using /sup 159/Tb(p,4n)/sup 156/Dy]

Study of the energy levels of /sup 156/Dy through the /sup 159/Tb(/b p/,4/b n/)/sup 156/Dy reaction has revealed the existence of six states with excitation energies between 1.8 and 2.8 MeV and spins between 6 and 12. Some of them can tentatively be assigned as low-spin members of `upper' bands which are thought to be responsible for the backbending phenomenon experimentally observed in the ground-state of beta -vibrational bands of this nucleus. Others could be levels of a negative-parity octupole band.Anglai