Autodetachment of Diatomic Carbon Anions from Long-Lived High-Rotation Quartet States.

We show that strong molecular rotation drastically modifies the autodetachment of C_{2}^{-} ions in the lowest quartet electronic state a^{4}Σ_{u}^{+}. In the strong-rotation regime, levels of this state only decay by a process termed "rotationally assisted" autodetachment, whose theoretical description is worked out based on the nonlocal resonance model. For autodetachment linked with the exchange of six rotational quanta, the results reproduce a prominent, hitherto unexplained electron emission signal with a mean decay time near 3 ms, observed on stored C_{2}^{-} ions from a hot ion source.

Merged-Beams Study of the Reaction of Cold HD^{+} with C Atoms Reveals a Pronounced Intramolecular Kinetic Isotope Effect.

We present a merged-beams study of reactions between HD^{+} ions, stored in the Cryogenic Storage Ring (CSR), and laser-produced ground-term C atoms. The molecular ions are stored for up to 20 s in the extreme vacuum of the CSR, where they have time to relax radiatively until they reach their vibrational ground state (within 0.5 s of storage) and rotational states with J≤3 (after 5 s).

Velocity map imaging with no spherical aberrations.

Velocity map imaging (VMI) is a powerful technique to deduce the kinetic energy of ions or electrons that are produced from a large volume in space with good resolution. The size of the acceptance volume is determined by the spherical aberrations of the ion optical system. Here we present an analytical derivation for velocity map imaging with no spherical aberrations.

Tracking Permeation of Dimethyl Sulfoxide (DMSO) in Shoot Tips Using Coherent Raman Microscopy.

Cryopreservation has emerged as a low-maintenance, cost-effective solution for the long-term preservation of vegetatively propagated crops. Shoot tip cryopreservation often makes use of vitrification methods that employ highly concentrated mixtures of cryoprotecting agents; however, little is understood as to how these cryoprotecting agents protect cells and tissues from freezing. In this study, we use coherent anti-Stokes Raman scattering microscopy to directly visualize where dimethyl sulfoxide (DMSO) localizes within shoot tips.

Isochronous mass spectrometry in an electrostatic storage ring.

For sensitive studies of molecular ions in electrostatic storage rings, the exact knowledge of the isobaric composition of stored beams from a variety of ion sources is essential. Conventional mass-filtering techniques are often inefficient to resolve the beam components. Here, we report the first isochronous mass spectrometry in an electrostatic storage ring, which offers a high mass resolution of Δm/m < 1 × 10 even for heavy molecular species with m > 100 u and uncooled ion beams.