US4034032A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for foam encapsulating laser targets
Assignee: Energy Research and Development Administration ERDA
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Filing: 1975-09-02
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Granted: 1977-07-05
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Expires: 1995-09-02
Abstract
Abstract Foam encapsulated laser fusion targets are made by positioning a fusion fuel-filled sphere within a mold cavity of suitable configuration and dimensions, and then filling the cavity with a material capable of producing a low density, microcellular foam, such as cellulose acetate dissolved in an acetone-based solvent. The mold assembly is dipped into an ice water bath to gel the material and thereafter soaked in the water bath to leach out undesired components, after which the gel is frozen, then freeze-dried wherein water and solvents sublime and the gel structure solidifies into a low-density microcellular foam, thereafter the resulting foam encapsulated target is removed from the mold cavity. The fuel-filled sphere is surrounded by foam having a thickness of about 10 to 100 mu m, a cell size of less than 2 mu m, and density of 0.065 to 0.6 x 103 kg/m3. Various configured foam-encapsulated targets capable of being made by this encapsulation method are illustrated.
Inventors
- 👤 Charles D. Hendricks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:36
CPC Classifications
G; G21; G21B; G21B1/00; G21B1/11; G21B1/19; C; C08; C08J; C08J9/00; C08J9/28; C08J2201/00; C08J2201/04; C08J2201/048; C08J2201/054; C08J2301/00; C08J2301/08; C08J2301/10; C08J2301/12; Y; Y02; Y02E; Y02E30/00; Y02E30/10; Y10; Y10S; Y10S376/00; Y10S376/916; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
164 words
A method for encapsulating a quantity of fusion fuel in a foam having a density of about 0.065 to 0.6× 10 3 kg/m 3 , a thickness of about 10 to 100 μm, and a cell size of up to about 2 μm comprising the steps of: positioning a fusion fuel-containing member having a cross-section of about 40 to 100 μm in a mold cavity formed in a desired configuration, filling the mold cavity with a solution comprising cellulose acetate and at least a swelling agent, placing the thus filled mold cavity in a bath of water having a temperature of 0°-10° C. causing the solution to gel, soaking the gel in a water bath to extract additives therefrom, freezing the thus soaked gel, freeze-drying the thus frozen gel such that water and solvents therein sublime and the gel structure solidifies into a low density microcellular foam containing the fusion fuel therein, and removing the thus formed fuel containing foam from the mold cavity.
Claim 2
Independent Claim
164 words
A method for encapsulating a quantity of fusion fuel in a foam having a density of about 0.065 to 0.6× 10 3 kg/m 3 , a thickness of about 10 to 100 μm, and a cell size of up to about 2 μm comprising the steps of: positioning a fusion fuel-containing member having a cross-section of about 40 to 100 μm in a mold cavity formed in a desired configuration, filling the mold cavity with a solution comprising cellulose acetate and at least a swelling agent, placing the thus filled mold cavity in a bath of water having a temperature of 0°-10° C. causing the solution to gel, soaking the gel in a water bath to extract additives therefrom, freezing the thus soaked gel, freeze-drying the thus frozen gel such that water and solvents therein sublime and the gel structure solidifies into a low density microcellular foam containing the fusion fuel therein, and removing the thus formed fuel containing foam from the mold cavity.
Claim 3
Dependent Claim
22 words
The method defined in claim 1, aadditionally including the step of attaching the thus formed fuel containing foam to a support member.
Claim 4
Dependent Claim
41 words
The method defined in claim 1, wherein the step of soaking the gel in the water bath is carried out in a time period of 16 to 24 hours and wherein the bath is maintained at a temperature of 0°-30° C.
Claim 5
Dependent Claim
31 words
The method defined in claim 1, wherein the step of freezing the gel is carried out by inserting same into liquid pentane having a temperature of about -70° to -18° C.
Claim 6
Dependent Claim
24 words
The method defined in claim 1, wherein the step of freezedrying the gel is carried out in a period of 4 to 8 hours.
Claim 7
Dependent Claim
42 words
The method defined in claim 1, additionally including the step of forming the solution by dissolving a quantity of cellulose acetate in a solution composed of magnesium perchlorate, water, ethyl lactate, and acetone at a temperature of about 25° to 50° C.
Claim 8
Dependent Claim
34 words
The method defined in claim 1, additionally including the step of forming the solution by dissolving a quantity of cellulose acetate in a solution composed of a solvent, a swelling agent and a non-solvent.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-04 | 1981-01-03 | 1981-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-04 | 1985-01-03 | 1985-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-04 | 1989-01-03 | 1989-07-05 | $7700.00 | Window Closed / Lapsed |