Patent US2236992A successfully refreshed from Google Patents.
Patent US3798565A successfully refreshed from Google Patents.
US3798565A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas cell atomic frequency standard of compact design
Assignee: Ball Corp
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Filing: 1972-12-14
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Granted: 1974-03-19
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Expires: 1992-12-14
Abstract
Abstract An atomic frequency standard comprising a cell arranged in the radiation path between a light source and a light sensitive signal generating means. Both the light source and the cell contain alkali metal vapor. A cavity resonator surrounds the cell. Means are provided for coupling one resonator to a frequency controllable oscillator. Means for applying a static homogenous magnetic field to the cell are also provided. The device contains an oscillator feedback control system responsive to the increased light absorption occurring when resonator oscillations coincide with an electron transition of the alkali metal. The cell substantially completely fills the cavity resonator and follows its contours. At least one concavity is provided on the cell wall into which a projection extends to promote stable oscillation modes within the cell.
Inventors
- 👤 E Jechart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:36
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/26
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
214 words
An atomic frequency standard comprising a cavity resonator, a cell containing alkali metal in (vapour) vapor form, said cell being located within, substantially filling and being formed to follow the interior contours of said resonator, a light source containing alkali metal in (vapour) vapor form located on one side of said cell and light sensitive signal generating means on the other side of said cell such that a radiation path is formed from said light source, through said cell to said light sensitive signal generating means, a frequency controllable oscillator, means for coupling said oscillator to said resonator, means for applying a static homogeneous magnetic field to said cell, an oscillator feedback control system responsive to the signal generated by said light sensitive signal generating means for tuning said oscillator to the increased light absorption occurring when the oscillations of the resonator coincide with an electron transition of the alkali metal, at least one concavity on said cell wall and at least one projection of (metal or) a material selected from the group consisting of a metal, an insulator and a semi-conductor, (with) said insulator and semiconductor having a high dielectric constant, said material extending from the wall of the resonator into said concavity such that stable oscillation modes are promoted within said cell.
Claim 2
Dependent Claim
214 words
An atomic frequency standard comprising a cavity resonator, a cell containing alkali metal in (vapour) vapor form, said cell being located within, substantially filling and being formed to follow the interior contours of said resonator, a light source containing alkali metal in (vapour) vapor form located on one side of said cell and light sensitive signal generating means on the other side of said cell such that a radiation path is formed from said light source, through said cell to said light sensitive signal generating means, a frequency controllable oscillator, means for coupling said oscillator to said resonator, means for applying a static homogeneous magnetic field to said cell, an oscillator feedback control system responsive to the signal generated by said light sensitive signal generating means for tuning said oscillator to the increased light absorption occurring when the oscillations of the resonator coincide with an electron transition of the alkali metal, at least one concavity on said cell wall and at least one projection of (metal or) a material selected from the group consisting of a metal, an insulator and a semi-conductor, (with) said insulator and semiconductor having a high dielectric constant, said material extending from the wall of the resonator into said concavity such that stable oscillation modes are promoted within said cell.
Claim 3
Dependent Claim
27 words
An atomic frequency standard as claimed in claim 1, wherein said cavity resonator is formed as a cylinder with a diameter of about 25 to 40 mm.
Claim 4
Dependent Claim
37 words
The atomic frequency standard according to claim 2 comprising at least two concavities on said cell wall, said concavities being arranged substantially in the center of the length of said resonator and diametrically opposed to one another.
Claim 5
Dependent Claim
34 words
The atomic frequency standard according to claim 3 wherein each of said concavities has extending therein a projection, said projections extending into said concavities less than 80 percent of the radius of said cylinder.
Claim 6
Dependent Claim
26 words
The atomic frequency standard according to claim 4 wherein said projections extend into said concavities less than 50 per cent of the radius of said cylinder.
Claim 7
Dependent Claim
23 words
The atomic frequency standard as claimed in claim 3 wherein at least one of the projections is adjustable in respect of its length.
Claim 8
Dependent Claim
32 words
The atomIc frequency standard as claimed in claim 1 wherein the cell is arranged in the cavity resonator in such a way as to be supported at least by its peripheral wall.
Claim 9
Dependent Claim
25 words
The atomic frequency standard as claimed in claim 1 further comprising a thermostat for keeping the temperature of said cell at a constant elevated temperature.
Claim 10
Dependent Claim
31 words
The atomic frequency standard as claimed in claim 1 wherein said means for generating the static magnetic field comprises at least one magnetic coil wound directly on to the cavity resonator.
Claim 11
Dependent Claim
27 words
The atomic frequency standard as claimed in claim 8 further comprising means responsive to the said cell thermostat for controlling the magnitude of the applied magnetic field.
Claim 12
Dependent Claim
29 words
An atomic frequency standard as claimed in claim 10, characterized in that the light sensitive signal generating means is arranged in the thermostatically controlled interior of the cavity resonator.
Claim 13
Dependent Claim
41 words
An atomic frequency standard as claimed in claim 1 wherein said light source is a heatable thermostatically-controlled gas discharge lamp and means for adjusting the temperature of said lamp in accordance with the signal from the light sensitive signal generating means.
Claim 14
Dependent Claim
73 words
An atomic frequency standard as claimed in claim 1 further comprising a cavity resonator having double walls and wherein said means for coupling the oscillator to the cavity resonator comprises a capacitor and a diode, said capacitor having the double walls of the cavity as its plates with said diode being connected therebetween and having a port or window for the radiation between the light source and said light sensitive signal generating means.
Claim 15
Dependent Claim
39 words
An atomic frequency standard as claimed in claim 13, wherein a light-permeable dielectric is situated between the capacitor plates and extends over the window thereby preventing any convection between the interior of the cavity resonator and the outer air.
References Cited (Backward Citations)
US3248666A
Cited
US3388339A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |