A novel vacuum ultra violet lamp for metastable rare gas experiments

Abstract

We report on a new design of a vacuum ultra violet (VUV) lamp for direct optical excitation of high laying atomic states e.g. for excitation of metastable rare gas atoms. The lamp can be directly mounted to ultra high vacuum vessels (p ≤ 10 −10 mbar). It is driven by a 2.45 GHz microwave source. For optimum operation it requires powers of approximately 20 W. The VUV light is transmitted through a magnesium fluoride window, which is known to have a decreasing transmittance for VUV photons with time. In our special setup, after a run-time of the VUV lamp of 550 h the detected signal continuously decreased to 25 % of its initial value. This corresponds to a lifetime increase of two orders of magnitude compared to previous setups or commercial lamps.

Towards an Australian Atom-Trap Trace Analysis (ATTA) facility

“…A more efficient and cleaner metastable production technique could reduce measurement time, increase throughput, and allow measurement of smaller samples. While optical lamp-based excitation techniques have been considered before [2], here we explore two innovative laser excitation techniques: Multi-photon Excitation: We have experimentally measured two-photon transitions for optical excitation into the metastable level [3]. A two-photon excitation into krypton 2p6 state decays directly into the 1s5 metastable state with favourable (~75%) branching ratio, and we have demonstrated efficiencies of 2% per pulse, using a broad-bandwidth excitation source at 215nm.…”

Laser-based Noble-gas Metastable Excitation Techniques with Application to Atom Trap Trace Analysis

“…While optical lamp-based metastable excitation techniques have been considered before [2], laser-based schemes remain largely unexplored. Here we consider two laser-based optical excitation techniques and explore how they could benefit an ATTA measurement system.…”

All-optical production and trapping of metastable noble-gas atoms down to the single-atom regime

“…The optical production of metastable krypton in the electronic configuration 4p 5 5s[3/2] 2 (see Figure 1) is based on the absorption of two resonant photons (123.6 nm & 819 nm), followed by spontaneous emission of a photon (760 nm) [17]. In our setup, the radiation at 123.6 nm is provided by an array of home built VUV lamps [3] directly connected to the 2D MOT vacuum chamber (see Figure 2 & 3), while the infrared light is delivered by a 1.4 W laser system. The final decay to the desired metastable state occurs with a probability of 75%.…”