Helium barrier atom chamber
The present invention discloses a vacuum chamber having operating pressures in the ultra-high vacuum (UHV) range (10 −8 torr to 10 −13 torr) and incorporating transparent windows, said windows constructed from transparent materials (preferably glass), and having low helium permeability velocity under operating and storage conditions. Embodiments may also contain surface coatings on windows to reduce helium permeation. Also disclosed herein is a method for vacuum processing said chamber by heating entire chamber and exposing the inside and outside of the chamber windows to helium free environments. Methods for final sealing said chamber are also discussed. The vacuum chamber is useful as a container for optically-cooled atoms for use in quantum information and atomic clocks and as a sensor for magnetic fields, gravitational fields, and inertial effects.
1. A sealed vacuum chamber comprising:
an enclosure having a pressure in the range of about 10 −7 to about 10 −13 torr;
said enclosure further comprising no active pumping means;
said enclosure having at least one optically transparent window;
said window further comprising an aluminosilicate glass having a helium permeability velocity below about 1×10 −13 cm 2 /s at a temperature of about 25° C.;
wherein the enclosure further comprises an atom injecting source;
wherein the enclosure further comprises an atom collector;
wherein the atom injecting source supplies a plurality of like atoms into the enclosure; and
wherein an electromagnetic beam passing through the window effects an energy change to reduce the temperature of at least one like atom.
2. The chamber of claim 1 , wherein the aluminosilicate further comprises a composition ranging from about 4% to about 80% of alumina by weight.
3. The chamber of claim 1 , wherein said window has a thickness ranging from about 0.1 mm to about 2 cm.
4. The chamber of claim 1 , wherein the enclosure further comprises a glass panel structure having at least four glass panels.
5. The chamber of claim 4 , wherein the enclosure further comprises a rectangular cross section.
6. The chamber of claim 1 further comprising an all glass structure having a rectangular cross section in at least one plane and having an enclosure volume of less than about 250 cubic cm.
7. The vacuum chamber of claim 1 , wherein said optically transparent window has an average helium concentration within the glass that corresponds to a surface pressure that is less than about 10 −4 torr.
8. The vacuum chamber of claim 1 further comprising a port that can be reopened for subsequent recharging.
9. The vacuum chamber of claim 1 , wherein the enclosure further comprises at least 2 cavities separated by a barrier which has a fluid communication channel between the cavities.
10. The vacuum chamber of claim 9 , wherein the cavities are composed of an aluminasilicate glass and wherein at least one of the cavities has a volume smaller than about 8 cm 3 .
11. A sealed vacuum chamber comprising:
an enclosure having a pressure in the range of about 10 −7 to about 10 −13 torr;
said enclosure having at least one optically transparent window;
said enclosure further comprising no active pumping means;
wherein the optically transparent window is composed of an aluminosilicate glass and further comprises a layer of helium barrier material having a thickness ranging from about 0.335 nm to about 0.1 mm;
wherein the enclosure further comprises an atom injecting source;
wherein the enclosure further comprises an atom collector;
wherein the atom injecting source supplies a plurality of like atoms into the enclosure; and
wherein an electromagnetic beam passing through the window effects an energy change to reduce the temperature of at least one like atom.
12. The vacuum chamber of claim 11 , wherein the layer further comprises at least a single layer of graphene.
13. The vacuum chamber of claim 11 , wherein the layer further comprises at least a single layer of aluminum oxide.