Theory of simultaneous dipole and quadrupole excitation of the ion motion in a Penning trap

“…One example is the anti-rotating wall excitation technique [13], a circularly polarized field which can expand radially and axially the cloud in the trap. In addition, new separation methods like the SIMCO excitation [14,15] are also under study at MPIK in an FT-ICR test Penning trap set-up [16], to find the most efficient and the fastest method to separate large samples of isobaric species in a Penning trap. …”

Section: Isobar Separation In a Penning Trapmentioning

confidence: 99%

PIPERADE: A Penning-trap isobar separator for the DESIR low-energy facility of SPIRAL2

Ascher

Blank

Blaum

et al. 2014

EPJ Web of Conferences

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Abstract. A Penning-trap isobar separator is currently under construction at CENBG (Bordeaux, France) and MPIK (Heidelberg, Germany) for a future installation at the SPI-RAL2/DESIR facility. This device aims at purifying the radioactive ion beams from undesired species, in order to deliver highly pure samples of exotic nuclei to the different set-ups which will be installed in the DESIR hall. The present manuscript describes the context and the motivations to build such a system, the targeted characteristics, and the studies to find an efficient purification method for large samples of isobaric species. The DESIR facility at SPIRAL2The last decades have seen an extremely rapid development of Radioactive Ion Beam (RIB) facilities allowing important progress concerning the knowledge of the atomic nucleus. Exploring new territory of nuclei with extreme N/Z ratios allowed the discovery of new structures and behaviors of the nucleus, thus refining the theoretical nuclear models originally developed from observations on long-lived nuclei [1]. The future SPIRAL2 facility [2] at GANIL in Caen, France, will push the limits further and allow experiments with nuclei which are currently inaccessible. The DESIR hall will be the installation dedicated to low-energy studies and will host experimental set-ups for decay spectroscopy, laser spectroscopy and trap-based experiments, in order to study nuclear ground and excited state properties. Thanks to these three complementary techniques, key observables of nuclei far from stability will be accessible, allowing to answer many of the open questions concerning the nuclear forces, the processes of nucleosynthesis as well as testing the Standard Model. The DESIR facility will be equipped with different beam lines which will receive low-energy beams (10-60 keV) from: (i) the existing SPIRAL1 facility, (ii) the SPIRAL2 production building using neutron-and deuteron-induced fission, deep-inelastic and fusion evaporation reactions and (iii) the super separator spectrometer S 3 where neutron-deficient and superheavy elements will be produced via in-flight fusion evaporation reactions. The combination of the complementary in-flight and ISOL methods and of many different reaction mechanisms using unprecedented high intensities will make the DESIR facility a powerful and versatile low-energy facility. The construction of the DESIR hall will begin in 2016. a

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The interconversion of the radial motional modes of an ion in a Penning trap mass spectrometer by 4n‐polar external radio frequency fields (n = 1,2,3,4)

Kretzschmar

2013

Annalen der Physik

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In Penning trap mass spectrometry ion masses are determined by measuring the free cyclotron frequency ν c = qB/(2π m) via the resonant conversion of the magnetron into the cyclotron motional mode, induced by the interaction with an external radio-frequency field. With octupolar rf-fields of frequency ν rf ≈ 2ν c the mass resolution has been improved by more than an order of magnitude as compared to conventional quadrupolar fields of frequency ν rf ≈ ν c and with the same pulse duration. This result raises the question what one might expect from using 12-polar rffields with frequency ν rf ≈ 3ν c or even 16-polar rf-fields with frequency ν rf ≈ 4ν c .In this paper the theoretical model for the interconversion of the radial modes by quadrupolar and octupolar rffields is generalized to general 4n-polar fields. As in the earlier work the complex amplitudes of the cyclotron and magnetron oscillators are used as dynamical variables and the Hamiltonian equations of motion are reformulated in terms of Bloch vector components. The resulting non-linear differential equations can be solved numerically.Results are presented on excitation functions (conversion at the exact resonance frequency) and on conversion line shapes (dependence of conversion on the detuning parameter). The most important observation is the decrease of the resonance width by a factor of 2 × 10 3 as one passes from quadrupolar (n = 1) to 12-polar (n = 3) and 16-polar (n = 4) excitation.

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Theory of simultaneous dipole and quadrupole excitation of the ion motion in a Penning trap

Cited by 9 publications

References 25 publications

High-resolution mass separation by phase splitting and fast centering of ion motion in a Penning trap

High-resolution mass separation by phase splitting and fast centering of ion motion in a Penning trap

PIPERADE: A Penning-trap isobar separator for the DESIR low-energy facility of SPIRAL2

The interconversion of the radial motional modes of an ion in a Penning trap mass spectrometer by 4n‐polar external radio frequency fields (n = 1,2,3,4)

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