A5081996426- Atomic and Molecular Physics
- Particle accelerators and beam dynamics
- Mass Spectrometry Techniques and Applications
- Advanced Chemical Physics Studies
- Particle Accelerators and Free-Electron Lasers
- Nuclear physics research studies
- Laser-induced spectroscopy and plasma
- Magnetic confinement fusion research
- X-ray Spectroscopy and Fluorescence Analysis
- Cold Atom Physics and Bose-Einstein Condensates
- Laser-Plasma Interactions and Diagnostics
- Plasma Diagnostics and Applications
- Nuclear Physics and Applications
- Astrophysics and Star Formation Studies
- Muon and positron interactions and applications
- Laser-Matter Interactions and Applications
- Superconducting Materials and Applications
- Ion-surface interactions and analysis
- Electron and X-Ray Spectroscopy Techniques
- Advanced Frequency and Time Standards
- Quantum, superfluid, helium dynamics
- Atomic and Subatomic Physics Research
- Radiation Therapy and Dosimetry
- Spectroscopy and Laser Applications
- Advanced Data Storage Technologies
Max Planck Institute for Nuclear Physics
2016-2025
Max Planck Society
2006-2016
Weizmann Institute of Science
1996-2016
Columbia University
2016
Kyoto Bunkyo University
2012
Kyoto University
2007-2012
UCLouvain
2010
Kyoto University Institute for Chemical Research
2007
Heidelberg University
1991-2002
Ludwig-Maximilians-Universität München
2002
Neutron-induced reaction cross sections of short-lived nuclei are imperative to understand the origin heavy elements in stellar nucleosynthesis and for societal applications, but their measurement is extremely complicated due radioactivity targets involved. One way overcoming this issue combine surrogate reactions with unique possibilities offered by heavy-ion storage rings. In work, we describe first surrogate-reaction experiment inverse kinematics, which successfully conducted at...
In chemistry and biology, chirality, or handedness, refers to molecules that exist in two spatial configurations are incongruent mirror images of one another. Almost all biologically active chiral, the correct determination their absolute configuration is essential for understanding development processes involving chiral molecules. Anomalous x-ray diffraction vibrational optical activity measurements broadly used determine solid liquid samples. Determining gas phase still a formidable...
The probabilities for γ-ray and particle emission as a function of the excitation energy decaying nucleus are valuable observables constraining ingredients models that describe deexcitation nuclei near threshold. These essential in nuclear astrophysics applications. In this paper, we have first time simultaneously measured neutron <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mmultiscripts><a:mi>Pb</a:mi><a:mprescripts/><a:none/><a:mn>208</a:mn></a:mmultiscripts></a:math>....
The first successful laser cooling of ions at relativistic energies was observed the Heidelberg TSR storage ring. A $^{7}\mathrm{Li}^{+}$-ion beam 13.3 MeV oberlapped with resonant copropagating and counterpropagating beams. metastable were cooled from 260 K to a longitudinal temperature below 3 decelerated by several keV. velocity distribution determined fluorescence method. After strongly enhanced narrow peak appeared in Schottky noise spectrum addition uncooled ion distribution.
State-resolved cross sections for the dielectronic recombination of hydrogenlike oxygen ions with free electrons have been measured first time using electron cooling device in heavy-ion Test Storage Ring Heidelberg. Energies and individual terms configuration 2l2l' were determined. Two-electron resonances 2lnl' n\ensuremath{\ge}3 contribute 90% to total dielectronic-recombination section. are reasonable agreement available calculations.
An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, put into operation. With a circumference 35 m, the ion-beam vacuum chambers all beam optics are in cryostat cooled by closed-cycle liquid helium system. At temperatures as low (5.5 ± 1) K inside time constants several minutes almost an hour were observed atomic molecular, anion cation at 60 keV. The intensity, energy-dependent...
The cross section as well the branching ratios for dissociative recombination of ground-state ${\mathrm{CH}}^{+}$ ions with electrons have been measured using heavy-ion storage-ring technique and two-dimensional fragment imaging. Although absolute value at thermal energies is found to be in very good agreement theory, several unpredicted narrow resonances are also present data. These structures interpreted due an indirect process via core-excited Rydberg states. branching-ratio measurement...
The first observation of laser-induced recombination, performed with merged beams protons, electrons, and laser photons in an ion storage ring, is reported. process was used to study the photorecombination spectrum high resolution. Deviations from earlier theoretical predictions turned out be due a weak external electric field could well described by simple extension field-free quantum-mechanical theory, based on properties classical electron trajectories combined Coulomb fields.
The radiative decay rate of ${\mathrm{C}}^{4+}$ ions in the metastable 1s2${\mathit{s}}^{3}$${\mathit{S}}_{1}$ state has been measured at ion storage ring TSR Heidelberg, observing time dependence dielectronic recombination on resonances characteristic for this state. very accurate result 48.57\ifmmode\pm\else\textpm\fi{}0.11 ${\mathit{s}}^{\mathrm{\ensuremath{-}}1}$ allows us to distinguish between different theoretical approaches. Our is excellent agreement with a calculation...
We report on the realization and operation of a fast ion beam trap linear electrostatic type employing liquid helium cooling to reach extremely low blackbody radiation temperature residual gas density and, hence, long storage times more than 5 min which are unprecedented for keV beams. Inside pipe that can be cooled temperatures <15 K, with 1.8 K reached in some locations, an pulse stored at kinetic energies 2-20 between two mirrors. Along overview cryogenic design, we present measurement...
Enhanced abundance of primordial HeH + Though only recently detected in space, the helium hydride ion (HeH ) is thought to be first molecule ever have formed early Universe. Novotný et al. report state-specific rate coefficients for dissociative reaction with electrons, obtained using a cryogenic storage ring combined merged electron beam (see Perspective by Bovino and Galli). They detect substantial rotational dependence decrease rates lowest states , far below values listed astrochemistry...
We present a merged-beams study of reactions between <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msup><a:mrow><a:mi>HD</a:mi></a:mrow><a:mrow><a:mo>+</a:mo></a:mrow></a:msup></a:mrow></a:math> ions, stored in the Cryogenic Storage Ring (CSR), and laser-produced ground-term C atoms. The molecular ions are for up to 20 s extreme vacuum CSR, where they have time relax radiatively until reach their vibrational ground state (within 0.5 storage) rotational...
We have momentum-analyzed electrons and recoil ions in triple coincidence with projectiles neutralized 300-keV <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mi mathvariant="normal">S</a:mi><a:msup><a:mrow><a:mi mathvariant="normal">i</a:mi></a:mrow><a:mo>−</a:mo></a:msup><a:mo>+</a:mo><a:mi>Ar</a:mi></a:mrow></a:math> collisions. The experiment was performed at a cryogenic ion storage ring an in-ring reaction microscope. Differential momentum distributions for detachment...
Radiative recombination (inverse photoionization) is believed to be well understood since the beginning of quantum mechanics. Still, modern experiments consistently reveal excess rates at very low electron-ion center-of-mass energies. In a detailed study on F6+ and C6+ ions with magnetically guided electrons we explored yet unexplained rate enhancement, its dependence magnetic field B, electron density n(e), beam temperatures T( perpendicular) ||). The scales as T(-1/2)( and, surprisingly,...
The term beta-beam has been coined for the production of a pure beam electron neutrinos or their antiparticles through decay radioactive ions circulating in storage ring. This concept requires to be accelerated Lorentz gamma 150 6He and 60 18Ne. neutrino source itself consists ring this energy range, with long straight sections line experiment(s). Such does not exist at CERN today, nor high-intensity proton ions. Nevertheless, existing accelerator infrastructure could used as would still...
The dissociative recombination cross section between ${\mathrm{HD}}^{+}$ molecules and electrons at energies 0.3 40 eV has been measured for the first time in an ion storage ring. beam, stored with a mean lifetime of \ensuremath{\sim}5 s, was observed to be vibrationally cold. In section, theoretically predicted high-energy resonances appeared, which can attributed via doubly excited Rydberg states HD.
A feasibility test of a new method to polarize beams strongly interacting charged particles circulating in storage ring is described. The stored particles, here protons, pass through polarized hydrogen gas target (thickness 6\ifmmode\times\else\texttimes\fi{}${10}^{13}$ H/${\mathrm{cm}}^{2}$) the some ${10}^{10}$ times and become partially because one spin state attenuated faster than other. polarization buildup clearly demonstrated present experiment.
Photodetachment thermometry on a beam of OH− in cryogenic storage ring cooled to below 10 K is carried out using two-dimensional frequency- and time-dependent photodetachment spectroscopy over 20 min ion storage. In equilibrium with the low-level blackbody field, we find an effective radiative temperature near 15 about 90% all ions rotational ground state. We measure J=1 natural lifetime (about 193 s) determine transition dipole moment 1.5% uncertainty. also rotationally dependent relative...
We have studied the photodissociation of ${\mathrm{CH}}^{+}$ in Cryogenic Storage Ring at ambient temperatures below 10 K. Owing to extremely high vacuum cryogenic environment, we were able store beams with a kinetic energy $\ensuremath{\sim}60\text{ }\text{ }\mathrm{keV}$ for several minutes. Using pulsed laser, observed Feshbach-type near-threshold resonances rotational levels $J=0--2$ ${\mathrm{CH}}^{+}$, exclusively. In comparison updated, state-of-the-art calculations, find excellent...
Two-dimensional fragment imaging is used to determine branching ratios into final atomic states for dissociative recombination of vibrationally cold ${\mathrm{HD}}^{+}$ molecules with electrons at variable energy. For low electron energies it found that the dissociation proceeds via $^{1}\ensuremath{\Sigma}_{g}^{+}$ state, leaving one fragments in $n\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}2$ level. At higher up $\ensuremath{\approx}20\mathrm{eV}$, a pronounced angular anisotropy...
We have performed measurements of the dissociative electron recombination (DR) ${\mathrm{H}}_{3}^{+}$ at ion storage ring TSR utilizing a supersonic expansion source. The source has been characterized by continuous wave cavity ring-down spectroscopy. present high-resolution DR rate coefficients for different nuclear spin modifications combined with precise fragment imaging studies internal excitation ions inside ring. resolve changes in energy dependence between ortho-${\mathrm{H}}_{3}^{+}$...
We present a novel experimental tool allowing for kinematically complete studies of break-up processes laser-cooled atoms. This apparatus, the 'MOTReMi,' is combination magneto-optical trap (MOT) and reaction microscope (ReMi). Operated in an ion-storage ring, new setup enables us to study dynamics swift ion-atom collisions on unprecedented level precision detail. In inaugural experiment with 1.5 MeV/amu O(8+)-Li pure ionization valence electron as well ionization-excitation lithium target...