A novel vacuum ultra violet lamp for metastable rare gas experiments

Daerr, H., Kohler, M., Sahling, P., Tippenhauer, S., Arabi-Hashemi, A., Becker, C., Sengstock, K., Kalinowski, M.

Published Jul 1, 2011• 10 citations

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 similar to 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. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3610465]

Related papers

Vacuum-ultraviolet light source for enhanced production of metastable krypton and xenon beams

Patrick Stollenwerk, K. Bailey, Daria B. Koch +4 more

We demonstrate excitation of metastable krypton and xenon beams using a vacuum ultraviolet lamp and directly compare the performance of this method to metastable excitation based on a radio-frequency-driven plasma discharge. In our apparatus, lamp-based metastable excitation outperforms the plasma discharge across a wide range of beam flux values relevant for atom trap trace analysis (ATTA). Moreover, we do not observe significant degradation in lamp performance after over 160 h of operation. We find that lamp-based excitation is particularly advantageous at the smallest and largest beam fluxes tested, demonstrating the utility of this approach both for improving krypton ATTA and for enabling the detection of radioactive xenon isotopes using ATTA. Finally, we demonstrate an additional enhancement to lamp-based metastable excitation efficiency and stability by applying an external magnetic field.

arXiv:2404.11493Physical Review ANov 13, 20241 citation

Optical production of metastable krypton

Linda Young, Donghai Yang, R. W. Dunford

We have investigated a new scheme for excitation of the 5s, J = 2 metastable level of Kr (5s[3/2] J = 2 ) which can be readily extended to other rare gases. In the scheme, an ultraviolet (UV) lamp is used to create a population of Kr atoms in the 5s[3/2] J = 1 level in a gas cell. The excited atoms are then pumped to the 5p[3/2] J = 2 level, using 819 nm light from a Ti:sapphire laser, from which they decay to the metastable state with a branching ratio of 77%. We made two striking observations: (1) the laser power required to saturate the second step decreases markedly as a function of gas cell pressure, and (2) the UV photon flux is converted with very high efficiency (≈10%) to metastable atom flux. A Monte Carlo study of the scattering of UV photons in the cell reproduces the trends observed. The understanding achieved points to the design of a higher flux source of metastable atoms.

Journal of Physics B Atomic Molecular and Optical PhysicsJun 25, 200227 citations

Thermal beam of metastable krypton atoms produced by optical excitation

Yue Ding, Shui-Ming Hu, K. Bailey +5 more

A room-temperature beam of krypton atoms in the metastable 5s[3/2]2 level is demonstrated via an optical excitation method. A Kr-discharge lamp is used to produce vacuum ultraviolet photons at 124 nm for the first-step excitation from the ground level 4p6 1S0 to the 5s[3/2]1 level. An 819 nm Ti:sapphire laser is used for the second-step excitation from 5s[3/2]1 to 5s[3/2]2 followed by a spontaneous decay to the 5s[3/2]2 metastable level. A metastable atomic beam with an angular flux density of 3 x 10(14) s(-1) sr(-1) is achieved at the total gas flow rate of 0.01 cm3/s at STP (or 3 x 10(17) at./s). The dependences of the flux on the gas flow rate, laser power, and lamp parameters are investigated.

arXiv:physics/0612046Review of Scientific InstrumentsFeb 1, 200725 citations

TUNABLE VACUUM-ULTRA VIOLET RADIATION GENERATED BY TWO-PHTON RESONANTFOUR-WAVE DIFFERENCE MIXING IN Hg VAPOR

Huang Xian-ling, Zongju Xia, ZOU YING-HUA +1 more

Vacuum-ultra violet radiation is generated by 61S0-61D2 or 61S0-63D2 two photon resonant four-wave difference mixing (ω4=2ω1-ω3) in Hg vapor. VUV radiation is tunable when one of the input wave (ω3) is tuned, the tuning range is 184.9-187.5 nm. The mechanism of this frenquency conversion, for example, the two-photon and single-photon resonant enhancement and phase matching have been investigeted. The competing processes and saturation effect on conversion efficiency have been analyzed. Using the generated tunable VUV radiation, we have recorded the absorption spetrum of O2 in air.

Acta Physica SinicaJan 1, 19900 citations

New Fluorescence Techniques for Detecting Noble Gases(*)

Tom J. Whitaker, Bret D. Cannon, Bruce A. Bushaw

Two new concepts for detecting noble gases are reported. Both techniques involve formation of the long-lived 1s5 metastable state of noble gases. The first technique utilizes the photon-burst method and should be capable of isotopically selective detection at extremely small relative abundances. The second concept incorporates a shelving technique that stores noble gas atoms in the metastable state and then pumps these atoms to a higher excited state that radiatively cascades to the ground state, emitting vacuum ultraviolet (VUV) photons. A significant advantage is that AlGaAs diode lasers can be used for the techniques rather than continuous wave cw dye lasers.

Laser Applications to Chemical, Security and Environmental AnalysisJan 1, 19870 citations

Optical Excitation of Metastable Krypton and Photoassociative Spectroscopy of Ultracold RbAr

Grady R. White

n this presentation, we discuss results from two separate bodies of work. In the first, we investigate all-optical excitation methods to produce metastable-state krypton. The high energies required to excite rare gases out of their ground state present a unique challenge in the context of laser experiments. Laser physics work with rare gases often relies on excitation within an RF discharge. All-optical excitation is a promising replacement for RF discharges, avoids problems caused by ion production and may eventually allow for higher efficiencies. We examine three separate methods of all-optical metastable-state production: using an ArF excimer laser, using the third harmonic of the Jefferson Lab free-electron laser (FEL), and using a commercially available UV lamp. In the second body of work, we perform photoassociation spectroscopy in an ultracold, heteronuclear Rb + Ar* system. Photoassociation is a method that may be used to both 1) produce ultracold molecules, and 2) perform high-resolution spectroscopy on excited molecular states. Most work within the field has been performed within all alkali-metal systems. We examine a unique noble gas–alkali system within a dual species magneto-optical trap. We have performed a comprehensive search for evidence of excitation to molecular levels of RbAr. We illuminate atom pairs with a photoassociation laser in a spectral region detuned a few GHz below an atomic asymptote of argon, analogous to previous work in the homo-nuclear argon or krypton systems. We discuss our methodology and findings. We conclude with a discussion of how our results may be applied to future spectroscopic searches

Jul 3, 20190 citations