Search results for "Ion beam"
showing 10 items of 297 documents
Versatile use of ion beams for diffusion studies by the modified radiotracer technique
2004
Abstract In the modified radiotracer technique ion beams within a broad energy range are employed. They include energetic light particles ensuring radioactive isotope production via nuclear reactions, keV-ion implantation of radiotracers and sputtering by low energy heavy ions for depth profiling. If the involved ion–solid interactions are properly taken into account, the technique provides an effective means for solid-state diffusion studies under demanding conditions. The various aspects related to the modified radiotracer technique are surveyed and discussed. The reliability of the procedure is demonstrated by comparisons with corresponding profiles obtained by secondary ion mass spectro…
Isospin symmetry in thesdshell: Transition strengths in the neutron-deficientsdshell nucleusAr33
2014
Reduced transition strengths of the deexciting transitions from the first two excited states in 33Ar were measured in a relativistic Coulomb excitation experiment at the GSI Helmholtz center. The radioactive ion beam was produced by fragmentation of a primary 36Ar beam on a 9Be target followed by the selection of the reaction product of interest via the GSI Fragment Separator. The 33Ar beam hit a secondary 197Au target with an energy of approximately 145 MeV/nucleon. An array of high-purity germanium cluster detectors and large-volume BaF2 scintillator detectors were employed for γ -ray spectroscopy at the secondary target position. The Lund-York-Cologne Calorimeter was used to track the ou…
Nuclear structure physics at GSI-challenges and perspectives
2001
Some characteristic examples from the ongoing GSI nuclear structure research programme are presented such as recent experimental results from nuclear reactions with exotic beams to explore the structure of halo nuclei, direct mass measurements in the storage ring, and the structure of heavy-elements. A brief outline of a next generation exotic beam facility will be given.
Laser spectroscopy of niobium fission fragments: first use of optical pumping in an ion beam cooler buncher.
2009
A new method of optical pumping in an ion beam cooler buncher has been developed to selectively enhance ionic metastable state populations. The technique permits the study of elements previously inaccessible to laser spectroscopy and has been applied here to the study of Nb. Model independent mean-square charge radii and nuclear moments have been studied for $^{90,90\text{ }\mathrm{m},91,91\text{ }\mathrm{m},92,93,99,101,103}\mathrm{Nb}$ to cover the region of the $N=50$ shell closure and $N\ensuremath{\approx}60$ sudden onset of deformation. The increase in mean-square charge radius is observed to be less than that for Y, with a substantial degree of $\ensuremath{\beta}$ softness observed …
X-ray fluorescence analysis by the fundamental parameters method without explicit knowledge of the excitation beam spectrum
2000
The results of analyses carried out with the fundamental parameters method without explicit knowledge of the beam exciting the sample are presented. The excitation beam is described by means of the fluorescence produced by a set of thick or thin targets of pure chemical elements. The results are compared with those obtained by using a semi-empirical model and an adjusted spectrum model, all sets of results being in turn compared with the actual chemical composition of the samples. It is concluded that the description of the excitation beam by means of the fluorescence produced on targets of pure elements is suitable for use with the fundamental parameters method. Copyright © 2000 John Wiley…
Recent Exploits of the ISOLTRAP Mass Spectrometer
2013
Abstract The Penning-trap mass spectrometer ISOLTRAP, located at the isotope-separator facility ISOLDE (CERN), is presented in its current form taking into account technical developments since 2007. Three areas of developments are presented. The reference ion sources have been modified to guarantee a sufficient supply of reference ions for mass measurements and systematic studies. Different excitation schemes have been investigated for manipulation of the ion motion in the Penning trap, to enhance either the purification or measurement process. A multi-reflection time-of-flight mass separator has been implemented and can now be routinely used for purification and as a versatile tool for bea…
First transmission of electrons and ions through the KATRIN beamline
2018
The Karlsruhe Tritium Neutrino (KATRIN) experiment is a large-scale effort to probe the absolute neutrino mass scale with a sensitivity of 0.2 eV (90% confidence level), via a precise measurement of the endpoint spectrum of tritium β-decay. This work documents several KATRIN commissioning milestones: the complete assembly of the experimental beamline, the successful transmission of electrons from three sources through the beamline to the primary detector, and tests of ion transport and retention. In the First Light commissioning campaign of autumn 2016, photoelectrons were generated at the rear wall and ions were created by a dedicated ion source attached to the rear section; in July 2017, …
Ion beam shaping and downsizing of nanostructures
2011
We report a new approach for progressive and well-controlled downsizing of nanostructures below the 10 nm scale. Low energetic ion beam (Ar+) is used for gentle surface erosion, progressively shrinking the dimensions with ~ 1 nm accuracy. The method enables shaping of nanostructure geometry and polishing the surface. The process is clean room / high vacuum compatible being suitable for various applications. Apart from technological advantages, the method enables study of various size phenomena on the same sample between sessions of ion beam treatment.
One dimensional arrays and solitary tunnel junctions in the weak coulomb blockade regime: CBT thermometry
1997
In this article we review the use of the tunnel junction arrays for primary thermometry. In addition to our basic experimental and theoretical results we stress the insensitivity of this method to the fluctuating background charges, to nonidealities in the array and to magnetic field. Important new results of this article are the low temperature corrections to the half width and depth of the measured conductance dip beyond the linear approximation. We also point ou that short arrays, single tunnel junctions in particular, show interesting deviations from the universal behaviour of the long arrays.
Isotope shift of40,42,44,48Ca in the 4s2S1/2→ 4p2P3/2transition
2015
We report on improved isotope shift measurements of the isotopes 40,42,44,48Ca in the 4s2S1/2→4p2P3/2 transition using collinear laser spectroscopy. Accurately known isotope shifts in the 4s2S1/2→4p2P1/2 (D1) transition were used to calibrate the ion beam energy with an uncertainty of ΔU ≈ ± 0.25 V. The accuracy in the D2 transition was improved by a factor of 5–10. A King-plot analysis of the two transitions revealed that the field shift factor in the D2 line is about 1.8(13)% larger than in the D1 transition which is ascribed to relativistic contributions of the 4p1/2 wave function.