Beam and installation improvements of the NIO1 ion source.

The NIO1 (Negative Ion Optimization phase 1) source can provide continuous beam operation, which is convenient for systematic parameter and equipment studies. Even in the pure volume production regime, the source yield was found to depend on conditioning procedures. Magnetic configuration tests continued adding magnets to the existing setup; the filter field component Bx has been progressively extended to span the -12 to 5 mT range, and as a trend, source performances improved with |Bx|. The progress of camera beam diagnostics and of the quality of the volume-produced H- beam is also shown. The status, off-line results, and reliability of a first NIO1 cesium oven are discussed; other upgrades in preparation (cavity ring down spectrometer, the end calorimeter, and conceptual tests of the energy recovery system) are also listed.

Development and installation of a radio frequency quadrupole cooler test.

A Radio Frequency Quadrupole Cooler (RFQC) prototype was adapted for insertion into a high uniformity magnetic field, with Bz up to 0.2 T, to improve radial confinement. While the RFQC purpose is to reduce (by gas collisions) the energy spread and emittance of a beam of radioactive nuclei, to finely select ion mass in nuclear physics, the prototype is tested in a setup including a stable ion source, a pepper pot emittance meter, and two Faraday cups; this makes a precise characterization of the RFQC feasible. The ion extraction was studied in detail by simulations, both to match it to the emittance meter granularity and to verify the effect of the typical nonuniformity of the longitudinal electric field Ez inside the RFQC; an average motion description (including friction force from gas collisions) was used, introducing the ballistic and diffusive regimes. With a preliminary optimization of the electrode shape, buffer gas pressure pg, and radio frequency voltage, the ion beam can be extracted with a significant cooling margin.

Integration of RFQ beam coolers and solenoidal magnetic fields.

Electromagnetic traps are a flexible and powerful method of controlling particle beams, possibly of exotic nuclei, with cooling (of energy spread and transverse oscillations) provided by collisions with light gases as in the Radio Frequency Quadrupole Cooler (RFQC). A RFQC prototype can be placed inside the existing Eltrap solenoid, capable of providing a magnetic flux density component B(z) up to 0.2 T, where z is the solenoid axis. Confinement in the transverse plane is provided both by B(z) and the rf voltage V(rf) (up to 1 kV at few MHz). Transport is provided by a static electric field E(z) (order of 100 V/m), while gas collisions (say He at 1 Pa, to be maintained by differential pumping) provide cooling or heating depending on V(rf). The beamline design and the major parameters V(rf), B(z) (which affect the beam transmission optimization) are here reported, with a brief description of the experimental setup.

Plasma-beam traps and radiofrequency quadrupole beam coolers.

Two linear trap devices for particle beam manipulation (including emittance reduction, cooling, control of instabilities, dust dynamics, and non-neutral plasmas) are here presented, namely, a radiofrequency quadrupole (RFQ) beam cooler and a compact Penning trap with a dust injector. Both beam dynamics studies by means of dedicated codes including the interaction of the ions with a buffer gas (up to 3 Pa pressure), and the electromagnetic design of the RFQ beam cooler are reported. The compact multipurpose Penning trap is aimed to the study of multispecies charged particle samples, primarily electron beams interacting with a background gas and/or a micrometric dust contaminant. Using a 0.9 T solenoid and an electrode stack where both static and RF electric fields can be applied, both beam transport and confinement operations will be available. The design of the apparatus is presented.

Scaling properties and intermittency of two-dimensional turbulence in pure electron plasmas.

When the cold nonrelativistic guiding center approximation is valid, the transverse dynamics of highly magnetized electron plasma columns confined in Penning-Malmberg traps is analogous to that of an incompressible, inviscid, two-dimensional (2D) fluid whose vorticity corresponds, up to a constant of proportionality, to the axially averaged electron plasma density. In this work intermittency phenomena in the freely decaying 2D electron plasma turbulence are investigated through scaling properties of the probability density functions and flatness of spatial vorticity increments, computed by analyzing the results of experiments performed in the Penning-Malmberg trap ELTRAP. It is shown that the intermittency properties of the turbulence strongly depends on the initial conditions and the relation of these results to the dynamics of the system is discussed.

Photon neutralizer as an example of an open billiard.

A simple photon cavity consisting of three flat mirrors is considered, which provides a model for a photon neutralizer of negative ion beams to be used in a neutral beam injector for plasma heating in fusion devices. Treating the system as an open mathematical billiard, the mechanism of photon scattering on the sharp boundary between two mirrors is described. Assuming a balance between the continuous injection of the photons into the device and their loss through its open ends, the stationary angular distribution of the photons in the trap is computed in closed form and an estimate for the confinement time of the photons in the neutralizer is provided.

Electrostatic diagnostics of nanosecond pulsed electron beams in a Malmberg-Penning trap.

A fast electrostatic diagnostic and analysis scheme on nanosecond pulsed beams in the keV energy range has been developed in the Malmberg-Penning trap ELTRAP. Low-noise electronics has been used for the detection of small induced current signals on the trap electrodes. A discrete wavelet-based procedure has been implemented for data postprocessing. The development of an effective electrostatic diagnostics together with proper data analysis techniques is of general interest in view of deducing the beam properties through comparison of the postprocessed data with the theoretically computed signal shape, which contains beam radius, length, and average density as fit parameters.

[25 years old woman with nocturia]. / Donna di 25 anni con nicturia.

A 25 years old lady presented to our outpatient clinic complaining nicturia, polyuria and polydipsia. On the basis of clinical assessment and the results of a simple test, a diagnosis of Nephrogenic Diabetes Insipidus (NDI) was made. The diagnosis of NDI is often missed, and appropriate treatment therefore delayed, with severe consequences especially in elderly and bed restricted people.

Role of the tricuspid annulus and the eustachian valve/ridge on atrial flutter. Relevance to catheter ablation of the septal isthmus and a new technique for rapid identification of ablation success.

BACKGROUND: Typical atrial flutter (AFL) results from right atrial reentry by propagation through an isthmus between the inferior vena cava (IVC) and tricuspid annulus (TA). We postulated that the eustachian valve and ridge (EVR) forms a line of conduction block between the IVC and coronary sinus (CS) ostium and forms a second isthmus (septal isthmus) between the TA and CS ostium. METHODS AND RESULTS: Endocardial mapping in 30 patients with AFL demonstrated atrial activation around the TA in the counter-clockwise direction (left anterior oblique projection). Double atrial potentials were recorded along the EVR in all patients during AFL. Pacing either side of the EVR during sinus rhythm also produced double potentials, which indicated fixed anatomic block across EVR. Entrainment pacing at the septal isthmus and multiple sites around the TA produced a delta return interval < or = 8 ms in 14 of 15 patients tested. Catheter ablation eliminated AFL in all patients by ablation of the septal isthmus in 26 patients and the posterior isthmus in 4. AFL recurred in 2 of 12 patients (mean follow-up, 33.9 +/- 16.3 months) in whom ablation success was defined by the inability to reinduce AFL, compared with none of 18 patients (mean follow-up, 10.3 +/- 8.3 months) in whom success required formation of a complete line of conduction block between the TA and the EVR, identified by CS pacing that produced atrial activation around the TA only in the counterclockwise direction and by pacing the posterior TA with only clockwise atrial activation. CONCLUSIONS: (1) The EVR forms a line of fixed conduction block between the IVC and the CS; (2) the EVR and the TA provide boundaries for the AFL reentrant circuit; and (3) verification of a complete line of block between the TA and the EVR is a more reliable criterion for long-term ablation success.

Left ventricular performance during the course of a day and meals in dilated cardiomyopathy and heart failure.

This study was performed to examine the influence of time during the day and of meals on left ventricular performance in patients with dilated cardiomyopathy and chronic congestive heart failure. Systolic time intervals and echocardiography were performed at set intervals with concomitant hemodynamic measurements in nine patients with chronic congestive heart failure over a 15 hour daytime period and during the three meals. Pulmonary capillary wedge pressure decreased (p less than 0.05) from a non-meal resting peak of 18 +/- 8 mm Hg at 1500 hours to 16 +/- 7 mm Hg at 2200 hours. The other non-meal cardiovascular variables, invasive and noninvasive, did not change significantly during the course of the day. Cardiac output and stroke volume rose and pulmonary and systemic vascular resistances, systemic blood pressure, pulmonary artery pressure, and pulmonary capillary wedge pressure generally fell significantly after meals. Although mean PEP/LVET tended to decrease and delta p/delta t increase after meals, these numerical changes were not statistically significant and none of the other noninvasive variables were affected by meals. Patients with dilated cardiomyopathy and chronic congestive heart failure have modest changes in central hemodynamics over the course of a day with rather striking changes with food ingestion. These alterations are generally not reflected in noninvasive cardiovascular parameters.

Oestrogen excretion and ovarian pathology in postmenopausal women with atypical hyperplasia, adenocarcinoma and mixed adenosquamous carcinoma of the endometrium.

Urinary oestrogen and pregnanediol excretion were measured before and after hysterectomy and bilateral salpingo-oophorectomy in 26 postmenopausal women with adenocarcinoma of the endometrium, 10 postmenopausal women with mixed adenosquamous carcinoma and 11 postmenopausal women with atypical hyperplasia (the patient groups). The results were compared with the values obtained in 22 active postmenopausal women, 20 hospitalized postmenopausal women and 18 women who had been subjected to hysterectomy and bilateral salpingo-oophorectomy for cancer of the cervix (the control groups). The ovaries and Fallopian tubes obtained at operation were examined for evidence of current or past excessive oestrogen production. Preoperative oestrogen values were higher in the patient groups than in the controls and the elevated values persisted after oophorectomy. The implications of these findings are discussed.

New developments in multiplier phototubes for space research.

Recent developments in ruggedized high-performance multiplier phototubes are described for the uv and visible. The spectral radiant responses of photocathodes with peak quantum efficiencies up to 30% and higher are detailed over the applicable spectral regions. Photoemissive surfaces with two types of spectral responses are included: (a) spectrally selective cathodes of the extreme solar-blind type for the far uv, and (b) cathodes with broad-band sensitivity over wide spectral ranges. The characteristics of dark current (dc and pulse counting), current amplification, equivalent noise input, and environmental conditions are reviewed for the various new tube types covered.