MACOR glass-ceramic based UHV cell for quantum technology applications

Abstract

Compact, customizable, non-magnetic vacuum systems are a key requirement for many field applications of quantum technology based on cold atoms. We report on the development and construction of a compact, low-cost ultra-high vacuum compatible cell using the glass-ceramic MACOR. The cell offers a CF flange connection to commercial vacuum technology, as well as high numerical aperture viewports for precision optical measurements. The presented technology shows stable vacuum pressures of $< 1 \cdot 10^{-10}$ mbar for more than a year since the implementation into the vacuum system of a quantum gas experiment, further proving suitability for general quantum technology applications.

Figures (6)

• Figure 1: Technical drawing of the metal flange to MACOR chamber connection. The wall thickness of the metal part was chosen to be 2.5 mm, while the glass ceramic conical extrusion has a minimum wall thickness of 4 mm.
• Figure 2: (a) Photograph of the glass-ceramic to metal flange technology. The lower part shows the metallic CF40 flange adapter with a conical mounting tube. The test cell (25 $\times$ 25 $\times$ 20 mm) made out of MACOR glass-ceramic can be easily inserted, after which an adhesive-based sealing of the conical mating, as well as the optical viewport, is established. (b) Photograph of the test chamber after the finished adhesive-based sealing procedure, here performed using Epotek 353ND.
• Figure 3: Technical drawing of the glass window to MACOR chamber connection for a 1" window. The diameter of the chamber recess and window are chosen such, that the clear aperture is fully covered and the depicted gap is formed. The thickness of the window (3.175 mm) is slightly larger than the chamber recess depth (3.0 mm) to prevent adhesive from spilling onto the window surface during the application process.
• Figure 4: Photographs of the aluminium viewports including a window after curing of the stated adhesives. 377 shows an increased leakage of adhesive into the viewport, indicated by the ring formation around the clear aperture.
• Figure 5: Picture of the MACOR science cell. Its full dimensions are denoted in the figure, featuring a 62x62x40 mm octagonal cell body and a 30 mm conical flange adapter. The nine optical window recesses are designed to hold commercial 0.75", 1" and 2" windows.