Speaker
Description
The Helmholtz Accelerator Mass Spectrometer Tracing Environmental Radionuclides (HAMSTER) facility [1] covers a wide range of applications from the environment to nuclear astrophysics.
For AMS, negative ions are extracted from a Rb or Cs sputter source and trace amounts of radionuclides are counted in a particle detector. A main limitation is the interference from stable isobars. Such interferences can be suppressed using the difference in electron affinities by laser-induced photodetachment. The Ion Linear Trap for Isobar Suppression (ILTIS) [2] decelerates a mass-filtered negative ion beam. Using He buffer gas, the residence time of the ions inside the ion cooler is increased to several milliseconds. A collinearly overlapped laser neutralizes negative ions at photon energies above the respective electron affinities or vertical detachment energies.
The setup also allows the determination of electron affinities.
We present results of the photodetachment of the BeF- molecule using an OPO laser scanning over a range of wavelengths from 1110 nm to 1310 nm and recording the intensity of the surviving anions. The resulting electron affinity of BeF- fully agrees with the literature value [3] and excited states of this molecule were observed. This technology is competitive to established techniques and opens applications of the HAMSTER for fundamental studies in atomic and molecular physics.
| Email address | l.widermann@hzdr.de |
|---|---|
| Funding Agency | BMFTR 05K25OD2, BMFTR 05K2022 |
| Visitor's Visa | no |
| Classification | Applications of Negative sources - medical (diagnostics, therapy), industrial (implantation, materials analysis, carbon dating, discovery science |
| Footnote | [1] A. Wallner et al. NIM B 2026, 570, 165890. [2] J. Lachner et al. NIM B 2026, 579, 166213. [3] M. L. Green et al. J. Phys. Chem. Lett. 2018, 9, 8b00784 |