• Physics 16, s59
The electric-field distribution inside a cold-ion cloud has been characterised utilizing Rydberg atoms embedded within the cloud—an method that could possibly be harnessed to optimize ion-beam sources.
Focused ion beams (FIBs) are highly effective instruments for imaging and getting ready supplies, semiconductor circuits, and organic samples. An essential class of FIB sources produces the ions from chilly, trapped impartial atoms—an method that provides excessive brightness and flexibility within the delivered ionic species. The electrical fields produced by the charged ions can degrade the beam high quality and brightness, however characterizing and controlling these fields has confirmed difficult. A brand new technique demonstrated by Alisher Duspayev and Georg Raithel of the University of Michigan, Ann Arbor, holds promise for overcoming this problem [1]. The technique, based mostly on embedding Rydberg atoms in an ion cloud, provides a noninvasive and versatile technique to probe the electric-field distribution within the cloud underneath a broad vary of circumstances.
The thought exploits the pronounced electric-field sensitivity of Rydberg atoms, which have their outermost electron excited right into a high-lying vitality stage the place it is just weakly certain. These atoms exhibit robust so-called Stark results, wherein an electrical area produces giant shifts of the atomic spectral traces. Duspayev and Raithel use laser beams to create each ions and Rydberg atoms from rubidium atoms trapped in a cavity. They then characterize the Rydberg spectra with high-precision spectroscopy. Analyzing such spectra, they reconstruct the electrical area produced by the ions contained in the ion supply. Importantly, the duo exhibits that, by utilizing two units of rubidium Rydberg states with totally different electron energies and angular momenta, the scheme can probe a broad vary of strengths and distributions of the electrical area skilled by the Rydberg atoms.
Next the duo plans to include the scheme right into a working FIB supply utilizing the derived electric-field info to drive a suggestions loop that optimizes the ion-beam high quality, says Raithel.
–Matteo Rini
Matteo Rini is the Editor of Physics Magazine.
References
- A. Duspayev and G. Raithel, “Electric field analysis in a cold-ion source using Stark spectroscopy of Rydberg atoms,” Phys. Rev. Appl. 19, 044051 (2023).