Potassium Vapor Cell, Pyrex – $350
25 mm OD x 75 mm Path Length
Flat Windows Attached Parallel
The purity level of the natural elements used in manufacturing all vapor cells is greater than 99% and is then distilled to an even higher purity during the filling process. Upon request, we offer buffer gases like Helium, Neon, Argon, Krypton, Xenon, Nitrogen, and Ethane as well as paraffin coating and OTS coating (additional charges may apply).
All vapor cells are helium leak checked and then baked under vacuum to the 10-8 Torr range for a minimum of 24 hours before they are filled with the selected element.
If ordering multiple cells please contact customer service for possible discounts.
Q: Do you offer AR coated windows?
A: Yes, we can offer double-side AR coated windows on any cell made from quartz with quartz or fused silica windows. We stock windows AR coated for 780-795 nm but we can offer most any AR coating although charges for a custom coating batch may apply.
Q: Can you offer AR coated windows on Pyrex cells?
A: Due to the coefficient of thermal expansion of Pyrex and heat required to attach the windows, at this time we are not able to offer double-side AR coated windows. AR coating can be applied to the outside surfaces of the windows once cells are constructed but the cost may be prohibitive for a small quantity of cells.
Q: Can I order a cell with uncoated or AR coated fused silica windows on a Pyrex cell body?
A: Due to the difference on coefficient of expansion, quartz or fused silica windows cannot be attached to a Pyrex cell body.
Q: How hot should I bake my cell?
A: Alkali metal vapor begins to react with Pyrex and quartz/fused silica in excess of 110-120C, although the reaction with Pyrex is slower. The higher the temperature, the faster the reaction until all alkali metal is consumed and no vapor exists to generate a signal. Standard vapor cells should be operated at no higher than 110C to ensure a long useful lifetime.
Q: How hot should I bake cells with anti-relaxation coating such as Paraffin or OTS?
A: Paraffin inside cells breaks down with too much heat. We recommend a maximum working temperature of 80C for cells with paraffin coating. OTS coating can withstand much higher temperatures up to 200C. However, please note prolonged contact between alkali vapor and OTS coating will cause the OTS to break down. Thus, we advise customers to collect the alkali material into the cold finger at the center of the cell (fill stem) when the cells are not in use.
Q: Do you offer Pyrex cells with wedged windows?
A: At this time, the process of fusing Pyrex windows to a Pyrex cell body makes attachment of wedged windows very difficult and can cause a high level of distortion and damage to the clear aperture of the windows. However, we can attach Pyrex windows at an angle with no issue.
Q: Can you measure the exact amount of alkali metal placed into each cell?
A: The process of placing alkali metal vapor into a cell is done on a manifold under vacuum through a glass fill stem. The cells are then closed leaving a small tip off. Because the resulting tip off can vary with each cell there is no accurate way to tare or weigh the cells prior to filling and determine a quantity of metal inside each cell. We estimate 5-10 mg of alkali material per cell. A “heavy” fill or large quantity of alkali material can be placed inside the cell upon request. Additional charges may apply for isotopically enriched materials.
Q: Do you leak check your cells prior to filling them to ensure they are UHV compatible?
A: Yes, every cell we produce is He leak checked down to 1E-9 CC/sec.