Effect of Fuel Doping in ICF Targets

Abstract

Inertial Confinement Fusion (ICF) reactor chambers can be designed to contain an ICF target being imploded and capture the resulting energy output from the reaction. The exact amount of energy required to facilitate this implosion depends on the specific target design in use. An ICF target design and implosion mechanism which is more robust against non-uniformities, simpler to analyze and simpler to utilize would be advantageous in achieving practical energy generation. Ideally, the ICF target will be configured to achieve a uniform temperature and density profile when imploding with a variety of parameters not limited to the following: a central region having an areal density (ρr) less than 1 g/cm2 at ignition and approximately 1% of the entire mass to be a material having a Z between 6 and 47 inclusive. Once the parameters of the ICF target are selected, one can easily smooth both the temperature and density profiles in the fusion fuel of non-equilibrium ignition targets without preventing runaway burn or affecting margin parameters such as fall-line greatly.

1 . A method for increasing the stability of an Inertial Confinement Fusion (ICF) system when igniting an ICF target, the method comprising:
 configuring an ICF target to achieve a uniform temperature and density profile when imploding, the ICF target comprising:
 a central region, wherein said central region comprises a mixture of a plurality of fusion fuel materials and having an areal density of less than approximately 1 g/cm 2  at ignition; and 
 a first shell directly surrounding and in direct contact with said central region, wherein said first shell comprises a material having a Z of 48 or greater; 
   doping the mixture of the central region with less than approximately 1% of total mass with a material having a Z between 6 and 47 inclusive, mixed throughout the central region; and   increasing the stability of a interface between the central region and first shell by adjusting the doping quantity.   
     
     
         2 . The method of  claim 1 , configuring the mixture of the central region to further comprise: a material having a Z of 48 or greater in addition to the material having a Z between 6 and 47 inclusive, mixed throughout the central region. 
     
     
         3 . The method of  claim 2 , further comprising: configuring the mixture of the central region to have an areal density of less than approximately 0.5 g/cm 2  at ignition. 
     
     
         4 . The method of  claim 3 , further comprising: doping the mixture of the central region with less than approximately 0.5% of total mass with a material having a Z between 6 and 47 inclusive, mixed throughout the central region. 
     
     
         5 . The method of  claim 4 , further comprising: doping the mixture of the central region with less than approximately 0.25% of total mass with a material having a Z between 6 and 47 inclusive, mixed throughout the central region. 
     
     
         6 . The method of  claim 5 , wherein the material having a Z between 6 and 47 inclusive, is Iron. 
     
     
         7 . The method of  claim 6 , further comprises: configuring the ICF target to include an outer fuel region and outer shell, wherein said outer shell directly surrounds said outer fuel region which directly surrounds said first shell which directly surrounds said inner fuel region. 
     
     
         8 . The method of  claim 7 , further comprising: uniformly mixing the plurality of fusion fuel material throughout the central region. 
     
     
         9 . The method of  claim 1 , further comprising: configuring the mixture of the central region to have an areal density of less than 0.7 g/cm 2 . 
     
     
         10 . The method of  claim 9 , further comprises: configuring the ICF target to include an outer fuel region and outer shell, wherein said outer shell directly surrounds said outer fuel region which directly surrounds said first shell which directly surrounds said inner fuel region. 
     
     
         11 . A system for increasing the stability of an Inertial Confinement Fusion (ICF) system when igniting an ICF target, the system comprising:
 an ICF target to achieve a uniform temperature and density profile when imploding, the ICF target comprising:
 a central region, wherein said central region comprises a mixture of a plurality of fusion fuel materials; 
 a first shell directly surrounding and in direct contact with said central region, wherein said first shell comprises a material having a Z of 48 or greater; 
   wherein the mixture of the central region has an areal density of less than approximately 1 g/cm 2  at ignition;   wherein at least one of the plurality of fusion fuel materials from the mixture in the central region has less than approximately 1% of total mass of a material having a Z between 6 and 47 inclusive, mixed throughout the central region.   
     
     
         12 . The system of  claim 11 , the central region further comprising: the mixture to include a material having a Z of 48 or greater in addition to the material having a Z between 6 and 47 inclusive, uniformly mixed throughout the central region. 
     
     
         13 . The system of  claim 12 , further comprising: the mixture of the central region to have an areal density of less than approximately 0.5 g/cm 2  at ignition. 
     
     
         14 . The system of  claim 13 , further comprising: at least one of the plurality of fusion fuel materials from the mixture in the central region to have less than approximately 0.5% of total mass, a material having a Z between 6 and 47 inclusive mixed throughout the central region. 
     
     
         15 . The system of  claim 14 , further comprising: at least one of the plurality of fusion fuel materials from the mixture in the central region to have less than approximately 0.25% of total mass, a material having a Z between 6 and 47 inclusive mixed throughout the central region. 
     
     
         16 . The system of  claim 15 , wherein the material having a Z between 6 and 47 inclusive, is Iron. 
     
     
         17 . The system of  claim 16 , wherein the ICF target further comprises: an outer fuel region and outer shell, wherein said outer shell directly surrounds said outer fuel region which directly surrounds said first shell which directly surrounds said inner fuel region. 
     
     
         18 . The system of  claim 17 , further comprising: the plurality of fusion fuel material are uniformly mixed throughout the central region. 
     
     
         19 . The system of  claim 11 , wherein the ICF target further comprises: the central region having an areal density of less than 0.7 g/cm 2 . 
     
     
         20 . The system of  claim 19 , wherein the ICF target further comprises: an outer fuel region and outer shell, wherein said outer shell directly surrounds said outer fuel region which directly surrounds said first shell which directly surrounds said inner fuel region.