46 research outputs found
Zeeman slowers made simple with permanent magnets in a Halbach configuration
We describe a simple Zeeman slower design using permanent magnets. Contrary
to common wire-wound setups no electric power and water cooling are required.
In addition, the whole system can be assembled and disassembled at will. The
magnetic field is however transverse to the atomic motion and an extra repumper
laser is necessary. A Halbach configuration of the magnets produces a high
quality magnetic field and no further adjustment is needed. After optimization
of the laser parameters, the apparatus produces an intense beam of slow and
cold 87Rb atoms. With a typical flux of 1 - 5 \times 10^10 atoms/s at 30 ms^-1,
our apparatus efficiently loads a large magneto-optical trap with more than
10^10 atoms in one second, which is an ideal starting point for degenerate
quantum gases experiments.Comment: 8+6 pages (article + appendices: calculation details, probe and oven
description, pictures), 18 figures, supplementary material (movie,
Mathematica programs and technical drawings
Systematic comparison of ISOLDE-SC yields with calculated in-target production rates
Recently, a series of dedicated inverse-kinematics experiments performed at
GSI, Darmstadt, has brought an important progress in our understanding of
proton and heavy-ion induced reactions at relativistic energies. The nuclear
reaction code ABRABLA that has been developed and benchmarked against the
results of these experiments has been used to calculate nuclide production
cross sections at different energies and with different targets and beams.
These calculations are used to estimate nuclide production rates by protons in
thick targets, taking into account the energy loss and the attenuation of the
proton beam in the target, as well as the low-energy fission induced by the
secondary neutrons. The results are compared to the yields of isotopes of
various elements obtained from different targets at CERN-ISOLDE with 600 MeV
protons, and the overall extraction efficiencies are deduced. The dependence of
these extraction efficiencies on the nuclide half-life is found to follow a
simple pattern in many different cases. A simple function is proposed to
parameterize this behavior in a way that quantifies the essential properties of
the extraction efficiency for the element and the target - ion-source system in
question.Comment: 46 pages, 49 figures, background information on
http://www-w2k.gsi.de/charms
Cold atoms in space: community workshop summary and proposed road-map
We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible road-map for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with the European Space Agency (ESA) and national space and research funding agencies
Cold atoms in space: community workshop summary and proposed road-map
We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible road-map for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with the European Space Agency (ESA) and national space and research funding agencies
Synthesis, structures, and selective toxicity to cancer cells of gold(I) complexes involving N-heterocyclic carbene ligands
New gold(I) complexes containing two 1-[2-(diethylamino)ethyl]imidazolydene ligands have been synthesized and characterized. The X-ray structures of two key compounds are presented. All complexes have been tested for their antiproliferative activities in prostate cancer cell line PC-3. Lipophilicity (Log P) has been determined for these complexes. The most active complex has been tested for the cytotoxic activities in five human cancer cell lines and primary endothelial cells. The most active complex demonstrated a potent selectivity for cancer cells
Evidence for sudden of rotational structure in heavy Sr nuclides
The authors give evidence for rotational 2/sup +/ and 4/sup +/ levels in /sup 100/Sr. The nuclide /sub 37//sup 100/Rb with half-life of 55 ms was produced by mass separation at the ISOLDE Facility by bombarding a uranium carbide target with 600 MeV protons. The gamma- ray spectrum shows peaks that the authors interpret from systematics as the 4/sup +/ to 2/sup +/ and 2/sup +/ to 0/sup +/ gamma-ray transitions in strontium. Similar measurements on /sup 98/Rb confirm earlier findings by Wollnick et al. (1977). The level diagrams clearly show an abrupt onset of deformation at N=60. (4 refs)