Search results for "Pumping"

Asymmetric nanopore rectification for ion pumping, electrical power generation, and information processing applications

2011

Single-track, asymmetric nanopores can currently be functionalised with a spatially inhomogeneous distribution of fixed charges and a variety of pore tip shapes. Optimising the asymmetric nanopore characteristics is crucial for practical applications in nanofluidics. We have addressed here this question for three cases based on different input/output chemical and electrical signals: (i) ion pumping up a concentration gradient by means of a periodic, time-dependent bias potential, (ii) information processing with a single nanopore acting as the nanofluidic diode of a logic gate, and (iii) electrical energy harvesting using a nanopore that separates two solutions of different salt concentrati…

Performance of a high repetition pulse rate laser system for in-gas-jet laser ionization studies with the Leuven laser ion source @ LISOL

2012

The Leuven Isotope Separator On-Line (LISOL) facility at the Cyclotron Research Center (CRC) Louvain-la-Neuve; The laser ionization efficiency of the Leuven gas cell-based laser ion source was investigated under on- and off-line conditions using two distinctly different laser setups: a low-repetition rate dye laser system and a high-repetition rate Ti:sapphire laser system. A systematic study of the ion signal dependence on repetition rate and laser pulse energy was performed in off-line tests using stable cobalt and copper isotopes. These studies also included in-gas-jet laser spectroscopy measurements on the hyperfine structure of 63Cu. A final run under on-line conditions in which the ra…

The FURIOS laser ion source at IGISOL-4

2013

Abstract The FURIOS laser ion source at the Accelerator Laboratory of the University of Jyvaskyla has been moved to a new location as a part of the IGISOL-4 facility. The laser ion source project had a high priority which allowed the transport of laser light to be optimized during the design phase. The laser resonators have been upgraded with a dual etalon configuration leading to greatly reduced laser linewidth. The transport efficiency of the dual-chamber gas cell has been determined using an alpha recoil source, with efficiencies ranging from a few percent in the beam interaction chamber to nearly 20% in the ionization chamber. In addition, we present recent results from the re-commissio…

Quadrupole interaction of $^{8}$Li and $^{9}$Li in LiNbO$_{3}$ and the quadrupole moment of $^{9}$Li

1988

The quadrupole interaction of nuclear spin polarized8Li (I=2) and9Li (I=3/2) in LiNbO3 has been studied at room temperature. The polarization was achieved by optical pumping of a fast atomic beam with circularly polarized laser light. The atoms were implanted into a hexagonal LiNbO3 single crystal and the quadrupole splitting ofβ-NMR spectra was measured. A ratio of ¦Q(9Li)/Q(8Li)¦=0.88(4) for the nuclear quadrupole moments was deduced, yielding a new value of ¦Q(9Li)¦=25.3 (9) mb for the quadrupole moment of9Li.

Optical polarization of neutron-rich sodium isotopes and β-NMR measurements of quadrupole moments

1996

The nuclear quadrupole moments of neutron-rich sodium isotopes are being investigated with the help of in-beam polarization by optical pumping in combination with $\beta$-NMR techniques. First measurements have yielded the quadrupole splittings of NMR signals in the lattice of LiNbO$_{3}$ for the isotopes $^{26}$Na, $^{27}$Na and $^{28}$Na. Interaction constants and ratios of the electric quadrupole moments are derived. In view of future experiments, $\beta$-decay asymmetries for the sequence of isotopes up to the $N$=20 neutron shell closure, $^{26-31}$Na, have been measured.

Laser spectroscopy and the properties of light nuclei near the neutron drip line

1993

The interesting nuclear structure phenomena observed in some light nuclei at the neutron drip line suggest the measurement of basic ground state properties such as spins, magnetic moments and electric quadrupole moments. Here it will be discussed what experiments are presently feasable using laser spectroscopy. For the outstanding example of a “halo” nucleus,11Li, the development of a technique combining β-asymmetry detected optical pumping in a fast beam with NMR spectroscopy has yielded pertinent results, the most recent of which is an experimental value of the nuclear quadrupole moment.

Laser spectroscopy and β-decay asymmetry from on-line implanted nuclei

1985

The method of collinear laser spectroscopy is combined with s-radiation detected optical pumping by implanting the optically oriented atoms into a cubic crystal.

Collisional ionization as a sensitive detection scheme in collinear laser-fast-beam spectroscopy

1986

Abstract State-selective collisional ionization of fast atomic beams is used to detect optical pumping. Counting of these ions is superior in sensitivity by several orders of magnitude to the conventional fluorescence detection, provided that the energy levels involved in the optical pumping process are sufficiently well separated. A straightforward application is envisaged in the collinear laser-fast-beam spectroscopy of rare-gas isotopes far from stability of which only very weak beams are available from on-line isotope separators.

On-line laser spectroscopy of short-lived mercury isotopes

1978

Evidence for anI=1 isomeric state in96Rb

1981

Aβ-RADOP (β-Radiation Detected Optical Pumping) experiment on the short lived (T1/2=203 ms)96Rb isotope has been performed at the on line mass separator for fission produced alkali isotopes at the TRIGA reactor in Mainz. Irradiation of r.f. onto the polarized sample to induce Zeeman transitions resulted in two signals for nuclear spinsI=2 andI=1. The previously undetermined component withI=1 is interpreted as evidence for an isomeric state in96Rb.