Observation of Atom-Wave Beats Using a Kerr Modulator for Atom Waves.

A phase modulation puts the atom in a coherent superposition of quantum states with different kinetic energies. We have detected the interference of such modulated waves at the output of our atom interferometer, and we have observed beats at the difference of the modulation frequencies and its harmonics, in good agreement with theory. The phase modulations were produced by a Kerr phase modulator, i.e., by the propagation of the atom wave in a time-dependent electric field. An extension of this technique to electron interferometry should open the way to very high temporal resolution in electron microscopy.

Note: A passively cooled heat pipe for spectroscopy.

We have developed and characterized a heat pipe for lithium spectroscopy, which is cooled only by air-convection, although its operating temperature is 330 °C: its construction is simple, of moderate cost and it is very reliable. A thermal model proves that heat-pipes without water cooling can be used up to considerably higher temperatures.

Measurement of the He-McKellar-Wilkens topological phase by atom interferometry and test of its independence with atom velocity.

In this Letter, we report a measurement of the He-McKellar-Wilkens (HMW) topological phase by atom interferometry. The experiment is done with our lithium atom interferometer, and in order to suppress the stray effects present in our first experiment, we use optical pumping of the (7)Li atoms in their F=2, m(F)=+2 (or -2) ground state sublevel. In these conditions, the measured phase shift is the sum of the HMW phase and of the Aharonov-Casher phase, which are separated due to their different m(F) dependence. The HMW phase has been measured for different lithium beam velocities and the results are in very good agreement with a phase independent of the atom velocity, as expected for a topological phase.

He-McKellar-Wilkens topological phase in atom interferometry.

We report an experimental test of the topological phase predicted by He and McKellar in 1993 and by Wilkens in 1994: this phase, which appears when an electric dipole propagates in a magnetic field, is connected to the Aharonov-Casher effect by electric-magnetic duality. The He-McKellar-Wilkens phase is quite small, at most 27 mrad in our experiment, and this experiment requires the high phase sensitivity of our atom interferometer with spatially separated arms as well as symmetry reversals such as the direction of the electric and magnetic fields. The measured value of the He-McKellar-Wilkens phase differs by 31% from its theoretical value, a difference possibly due to some as yet uncontrolled systematic errors.

First measurements of the index of refraction of gases for lithium atomic waves.

We report the first measurements of the index of refraction of gases for lithium waves. Using an atom interferometer, we have measured the real and imaginary parts of the index of refraction n for argon, krypton, and xenon as a function of the gas density for several velocities of the lithium beam. The linear dependence of (n-1) with the gas density is well verified. The total collision cross section deduced from the imaginary part of (n-1) is in very good agreement with traditional measurements of this quantity. Finally, the real and imaginary parts of (n-1) and their ratio rho exhibit glory oscillations, in good agreement with calculations.

New spectroscopic data, spin-orbit functions, and global analysis of data on the A 1Sigmau+ and b 3Piu states of Na2.

The lowest electronically excited states of Na2 are of interest as intermediaries in the excitation of higher states and in the development of methods for producing cold molecules. We have compiled previously obtained spectroscopic data on the A 1Sigmau+ and b 3Piu states of Na2 from about 20 sources, both published and unpublished, together with new sub-Doppler linewidth measurements of about 15,000 A<--X transitions using polarization spectroscopy. We also present new ab initio results for the diagonal and off-diagonal spin-orbit functions. The discrete variable representation is used in conjunction with Hund's case a potentials plus spin-orbit effects to model data extending from v=0 to very close to the 3 2S+3 2P12 limit. Empirical estimates of the spin-orbit functions agree well with the ab initio functions for the accessible values of R. The potential function for the A state includes an exchange potential for S+P atoms, with a fitted coefficient somewhat larger than the predicted value. Observed and calculated term values are presented in an auxiliary (EPAPS) file as a database for future studies on Na2.

Parallel temperatures in supersonic beams: ultracooling of light atoms seeded in a heavier carrier gas.

Supersonic expansion is a very powerful tool to produce an atomic beam with a well defined velocity and, by seeding a test gas in such an expansion, the energy of the test gas can be transferred, at least partially, to the very-low-temperature carrier gas. The case usually studied is the one of a heavy gas seeded in a light carrier gas and, in this case, the parallel temperature of the seeded gas is always larger than the one of the carrier gas. In the present paper, we study the opposite case which has received less attention: when a light gas is seeded in a heavier carrier gas, the parallel temperature can be substantially lower for the seeded gas than for the carrier gas. This effect has been first observed by Campargue and co-workers in 2000, in the case of atomic oxygen seeded in argon. In the present paper, we develop a theoretical analysis of this effect, in the high dilution limit, and we compare our theoretical results to several experimental observations, including a set of measurements we have made on a beam of lithium seeded in argon. The agreement between theory and experiments is good.

[Intracranial subdural hematoma after obstetric dural puncture]. / Hématome sous-dural intracrânien après brèche dure-mérienne en obstétrique.

The authors report a case of subdural haematoma (HSD), which occurred following epidural analgesia for labour, complicated by post dural puncture headache (PDPH). A 26-year-old woman displayed a typical PDPH following epidural anaesthesia. On the sixth day, she was given a blood patch (BP), which was partially efficacious. Because of worsening of the headache, of disappearance of the postural characteristics, and of vomiting without focal neurological signs on the 9th day, a CT-scan was done. The CT-scan showed a small hemispheric subdural haematoma. The recovery was complete with only medical treatment. HSD is a rare serious complication of dural puncture. When the characteristics of PDPH change, HSD should be evoked even without focal neurological signs. An early diagnosis and the small size of the haematoma may allow HSD to be treated medically and avoid surgical evacuation.

[Sheehan's syndrome: a recurrent obstetrical complication]. / Le syndrome de Sheehan: une complication obstétricale toujours d'actualité.

Case report of a 25-year-old primigravida who sustained a necrosis of the anterior pituitary gland after a haemorrhagic Caesarean section. The diagnosis was delayed, as the early symptoms (apathy, anorexia, nausea, orthostatic hypotension and hypoglycaemia) were imputed to more usual causes.

[Interactions between naltrexone, an opioid antagonist, and opioids administered during general anesthesia]. / Interférences entre la naltrexone, un antagoniste des morphiniques, et les morphiniques administrés pendant une anesthésie générale.

We report a case of a probable interaction between sufentanil and naltrexone, an oral long acting opioid antagonist, prescribed for maintenance of abstinence in alcoholics and opioid addicts. The interaction resulted in an antagonisation of the effects of sufentanil and the necessity to increase the dosage. Anaesthetists should be aware of this potential drug interaction.

[Catheter rupture at the site of implantation: a rare accident? Apropos of 2 observations]. / Rupture de cathéter sur site implantable: un accident rare? A propos de deux observations.

Seventy three venous access ports of the same type have been implanted recently in our hospital. We have observed two cases of catheter's rupture. Both accidents show a lot of similarities: material of the same trade mark; same way of implantation: right subclavian vein; rupture before one year; rupture at the point of entry of the subclavian vein; migration of the distal part of catheter; withdrawal of this part by right femoral vein's catheterism. Both broken catheters and another not broken (implanted during more than one year) were tested. It appears that those catheters were weakened, especially around the rupture. The reason is the long-standing compression of the catheter at the narrow space between clavicle and first rib. Then, the rupture of this weakened catheter could have been produced by the high pressure due to injection with small syringes.