Tijs van Roon | Searcharxiv

arXiv2025

High-power RF amplifier for ultracold atom experiments

We report on the design and characterization of a high-power amplifier with an output power of 36.5 dBm for a frequency range of 50 MHz to 1000 MHz with a total gain of 40 dB. The amplifier is optimized for driving acousto-optic and electro-optic modulators for ultracold atom experiments. This amplifier is a 19 inch rack unit, with a power efficiency of >35 %, and 0.01 dBm long-term stability. Schematics and other design materials are publicly available under an open hardware license.

physics.atom-ph↗

arXiv2023

Active stabilization of kilogauss magnetic fields to the ppm level for magnetoassociation on ultranarrow Feshbach resonances

Feshbach association of ultracold molecules using narrow resonances requires exquisite control of the applied magnetic field. Here we present a magnetic field control system to deliver magnetic fields of over 1000 G with ppm-level precision integrated into an ultracold-atom experimental setup. We combine a battery-powered current-stabilized power supply with active feedback stabilization of the magnetic field using fluxgate magnetic field sensors. As a real-world test we perform microwave spectroscopy of ultracold Rb atoms and demonstrate an upper limit on our magnetic field stability of 2.4(3) mG at 1050 G [2.3(3) ppm relative] as determined from the spectral feature.

physics.atom-ph↗