We have used a radio frequency quadrupole decelerator to decelerate antiprotons emerging from the CERN Antiproton Decelerator from MeV-to keV-scale energy, and collected five decelerated pulses in a multiring trap. Some 5 10 6 antiprotons were stacked in this way. Cooling of the trapped antiprotons by a simultaneously trapped electron plasma was studied nondestructively via shifts in plasma mode frequencies. We have also demonstrated the first step in extracting a 10 -500 eV antiproton beam from the trap.

HfO2 thin films with elemental substitutions were formed by chemical solution deposition. Bi substitution distorts the HfO2 lattice and increases the polarization value. (Bi,Nb) substitution compensates the charge balance to prevent the formation of oxygen vacancies. The relative dielectric permittivity of the HfO2 film with 5 mol % La, 5 mol % Bi, and 5 mol % Nb substitution under an applied DC field was observed to be up to 78. The constriction of the polarization–electric field (P–E) curve disappears at a temperature lower than that where the dielectric permittivity is maximum. The phase transition from the paraelectric tetragonal phase to the ferroelectric orthorhombic phase causes the constriction of the P–E curve to disappear. We consider that the high dielectric permittivity was due to the phase-transition-related phenomena.

Regional blood flow to major organs and regional cerebral blood flow were determined in seven anesthetized male gerbils by a modified microsphere method. Carbonized microspheres, 15 micrometers in diameter and labeled with 85Sr or 141Ce, were injected into the left ventricle by cardiac puncture through the closed thorax, and reference samples of known volume were withdrawn from tail-artery cannula. No significant hemodynamic alterations were observed during microsphere administration, and extraction of 15-micrometers microspheres by the pulmonary or systemic capillary beds was nearly 100%. The adequacy of mixing of microspheres in the left ventricle was also validated. The absolute regional blood flow to various organs and regional cerebral blood flow were expressed in terms of milliliters per minute per gram tissue weight, and the values mostly agreed with those reported previously in rats. The results indicate that the reference sample method can be applied to the gerbil. This method should allow the gerbil, which is an animal widely used in stroke research, to be conveniently used for hemodynamic studies when organ blood flow and regional cerebral blood flow are necessary.

A beam line for the transportation of slow antiprotons from a multiring electrode trap to an experimental chamber is described. The beam line is equipped with a three-stage differential pumping system in order to maintain a pressure lower than 1×10−12 Torr in the trap region while simultaneously having a pressure of around 1×10−6 Torr in the chamber. Tests have shown that 105 positive ions per trapping cycle were successfully extracted at 250 eV from the trap positioned in a superconducting solenoid. The ions were then further transported through three small apertures to the target area located 3.5 m downstream of the trap. Results from the first delivery of a 250 eV antiproton beam are described.

The nonlinear polarization responses of ZrO2-based thin films were investigated. Y, Ce, Ti, and Sn were used as substitutes in ZrO2 thin films by chemical solution deposition. A pure ZrO2 film and the ZrO2 film with 1% Y substitution showed constricted polarization–electric field (P–E) curves. In contrast, the ZrO2 film with 5% Y substitution showed a linear P–E curve. The dielectric constants of the pure ZrO2 film and the ZrO2 film with 1% Y substitution increased by 7 and 11%, respectively, under an applied electric field of 2.5 MV/cm. The nonlinearity of the polarization responses was decreased by Ce substitution and Ti substitution. The ZrO2 films with Sn substitution showed narrow P–E curves. The dielectric constant of the ZrO2 film with 10% Sn substitution increased by 13% under an applied electric field of 3 MV/cm. These dielectric constant increases originate from electric-field-induced phase transitions of ZrO2-based thin films.