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AbstractAbstract
[en] The absorption coefficients of the collision induced spectrum of the interaction H2-He at 300 K between 200 and 700 cm-1 are presented. A lack of absorption (dip) due to the intercollisional interference effect is clearly seen at the frequency of the pure rotation line S1 of the free molecule of H2
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Journal Article
Journal
Journal de Physique. Lettres; ISSN 0302-072X;
; v. 44(5); p. 183-187

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[en] We present a general framework in which non-linear optical phenomena for an ensemble of accelerated atoms can be studied. We show the equivalence of various approaches through frame transformations. This equivalence is understood within the context of a covariant formalism which is briefly sketched. The choice of the frame, in which the atoms are not accelerated but where the light spectrum and the atomic source term are correspondingly modified, leads to the simplest calculation. It enables one to use the usual density matrix diagrams and associated rules. Explicit examples are given in the case of a sinusoidal gravitational wave. Finally a brief discussion of the signal-to-noise ratio of the sidebands induced by gravitational waves on saturation resonances is outlined
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Journal Article
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Journal de Physique. Lettres; ISSN 0302-072X;
; v. 44(24); p. 983-990

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[en] After neutron activation, iridium samples have been kept at low temperature (22 K). The electrical resistivity decreases or increases with time according to whether the activation was moderate or high. A coherent interpretation is given implying the recoil-induced creation of a Frenkel pair during activation and its subsequent annihilation, with a probability approximately= 0.8, due to a second subthreshold recoil
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Journal Article
Journal
Journal de Physique. Lettres; ISSN 0302-072X;
; v. 44(6); p. 219-224

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[en] Two heavy ion interaction potentials have been computed using the same nuclear force. One has been obtained from symmetric semi-infinite nuclear matter slabs and the other one from finite nuclei. After a proximity scaling, two rather different universal functions are obtained. We argue that this is due to the different surface thickness of semi-infinite nuclear matter and finite nuclei. Consequently, it is the universal function obtained from the nucleus-nucleus systematics that should be used in the applications
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Journal Article
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Journal de Physique. Lettres; ISSN 0302-072X;
; v. 44(16); p. 685-688

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AbstractAbstract
[en] The first observation of the nuclear magnetic resonance of the uranium 235 is reported. It has been performed on pure liquid uranium hexafluoride at 380 K. The measured magnetogyric ratio is /γ(235U)/ = 492.6 +- 0.2 rad.s-1G-1
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Journal Article
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Numerical Data
Journal
Journal de Physique. Lettres; ISSN 0302-072X;
; v. 44(24); p. 1017-1019

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AbstractAbstract
[en] When a Hamiltonian H depends on variables phisub(i), the values of these variables which minimize H satisfy the equations deltaH/deltaphisub(i) = O. If this set of equations is solved by iteration, there is no guarantee that the solution is the one which minimizes H. In the case of a harmonic system with a random potential periodic with respect to the phisub(i)'s, the fluctuations have been calculated by Efetov and Larkin by means of the iteration method. The result is wrong in the case of a strong disorder. Even in the weak disorder case, it is wrong for a one-dimensional system and for a finite system of 2 particles. It is argued that the results obtained by iteration are always wrong, and that between 2 and 4 dimensions, spin-pair correlation functions decay like powers of the distance, as found by Aharony and Pytte for another model
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Journal Article
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Journal de Physique. Lettres; ISSN 0302-072X;
; v. 44(22); p. 889-895

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[en] We have extended to temperatures below 1 K the optical pumping technique for polarizing the nuclei of ground state 3He atoms in the gas phase. A superfluid 4He film covering the surface of the pyrex cell protected the 3He atoms from the rapid depolarization processes that would be experienced in the presence of bare pyrex walls. Relatively long relaxation times of order 103 s were observed at temperature down to 500 mK, the lowest temperature accessible with the present apparatus
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Journal Article
Journal
Journal de Physique. Lettres; ISSN 0302-072X;
; v. 44(13); p. 523-529

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AbstractAbstract
[en] The magnetic properties of NpSbTe and NpAsTe have been studied. NpSbTe remains paramagnetic down to 1.8K. NpAsTe is ferromagnetic below Tsub(c) = 25 K; the magnetization reaches 1.07μsub(B)/Np in a 40 kOe field but is not yet saturated. In the paramagnetic range, results for both compounds indicate a 3 + valence state of Np ions. In the case of NpAsTe, results are in agreement with recent crystal field calculation, Moessbauer effect and electrical resistivity measurements
[fr]
Les proprietes magnetiques de NpSbTe et NpAsTe ont ete etudiees. NpSbTe reste paramagnetique jusqu'a 1,8 K. NpAsTe devient ferromagnetique en dessous de Tsub(c) = 25 K; l'aimantation atteint 1,07 μsub(B)/atome de Np dans un champ magnetique de 40 kOe et n'est pas encore saturee. Dans la zone paramagnetique, les resultats pour les deux composes s'accordent avec un etat de valence + 3 pour le Np. Dans le cas de NpAsTe, les resultats s'accordent egalement avec de recents calculs de champ cristallin, des mesures d'effet Moessbauer et des mesures de resistiviteOriginal Title
Proprietes magnetiques de NpSbTe et NpAsTe
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Journal Article
Journal
Journal de Physique. Lettres; ISSN 0302-072X;
; v. 45(11); p. L.571-L.576

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AbstractAbstract
[en] Fission yields of two 136I isomers have been measured in the fission of 235U (n. therm. f) and 235U (n. 3 MeV, f). The results were obtained from γ spectrometry (Ge-Li) gross spectra. The isomeric ratio: Yi(136I(45s))/Yi(136I(45s))+Yi(136I(83s)) is respectively: 0.55+-0.05 (n. therm.) and 0.66+-0.07 (n. 3 MeV). J(RMS) values of: 5.9+-0.4 h and 7.0+-1.0 h are deduced
[fr]
Les rendements de fission des 2 isomeres de 136I ont ete mesures dans la fission de 235U (n. therm. f) et 235U (n. 3 MeV, f). Ces resultats ont ete obtenus par spectrometrie γ (Ge-Li) sans separation chimique. Le rapport isomerique: Yi(136I(45s))/Yi(136I(45s))+Yi(136I(83s)) est respectivement de: 0,55+-0,05 (n. therm.) et 0,66+-0,07 (n. 3 MeV). On en deduit des valeurs du moment angulaire moyen J(RMS) respectivement egales a 5,9+-0,4 h et 7,0+-1,0 hOriginal Title
Determination experimentale du rapport isomerique du 136I dans la fission thermique et par neutrons de 3 MeV de 235U
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Journal Article
Journal
Journal de Physique. Lettres; ISSN 0302-072X;
; v. 41(9); p. L.223-L.225

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BARYON REACTIONS, BARYONS, BETA DECAY RADIOISOTOPES, BETA-MINUS DECAY RADIOISOTOPES, ELEMENTARY PARTICLES, ENERGY RANGE, FERMIONS, HADRON REACTIONS, HADRONS, INTERMEDIATE MASS NUCLEI, IODINE ISOTOPES, ISOTOPES, MEV RANGE, MINUTES LIVING RADIOISOTOPES, NEUTRONS, NUCLEAR REACTION YIELD, NUCLEAR REACTIONS, NUCLEI, NUCLEON REACTIONS, NUCLEONS, ODD-ODD NUCLEI, RADIOACTIVE MATERIALS, RADIOISOTOPES, TARGETS
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AbstractAbstract
[en] A simplified method for studying the energetic and spatial statistical properties of ions confined in a quadrupole R.F. trap is proposed. A relation from a property of temporal invariance is deduced, and the results are tested with those obtained previously by a general method
[fr]
On propose une methode simplifiee d'etude des proprietes statistiques energetiques et spatiales d'ions confines dans une trappe quadrupolaire R.F. on etablit une relation basee sur une propriete d'invariance par translation temporelle, et on teste les resultats avec ceux obtenus anterieurement par une methode generaleOriginal Title
Invariance temporelle et proprietes statistiques energetiques et spatiales d'ions confines dans une trappe quadrupolaire R.F
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Journal Article
Journal
Journal de Physique. Lettres; ISSN 0302-072X;
; v. 40(24); p. L.633-L.638

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