System and method for small, clean, steady-state fusion reactors

Abstract

According to some embodiments, a system for widening and densifying a scrape-off layer (SOL) in a field reversed configuration (FRC) fusion reactor is disclosed. The system includes a gas box at one end of the reactor including a gas inlet system and walls of suitable heat bearing materials. The system further includes an exit orifice adjoining the gas box, wherein the exit orifice has a controllable radius and length to allow plasma to flow out from the gas box to populate the SOL with the plasma. The system may also include fusion products, which decrease in speed in the plasma in the SOL, allowing energy to be extracted and converted into thrust or electrical power and further allowing ash to be extracted to reduce neutron emissions and maintain high, steady-state fusion power.

What is claimed is: 
     
         1 . A system for widening and densifying a scrape-off layer (SOL) in a field reversed configuration (FRC) fusion reactor, comprising:
 a gas box at one end of the reactor comprising a gas inlet system and walls of suitable heat bearing materials; and   an exit orifice adjoining the gas box, wherein the exit orifice has a controllable radius and length to allow plasma to flow out from the gas box to populate the SOL with the plasma.   
     
     
         2 . The system of  claim 1 , wherein the plasma in the gas box has a peak electron temperature in the range 1-50 eV and a peak density in the range 3×10 16  cm −3  to 3×10 13  cm −3 . 
     
     
         3 . The system of  claim 1 , wherein the plasma in the SOL has a peak temperature in the range 10-200 eV and a peak density in the range 5×10 14  cm −3  to 3×10 13  cm −3 . 
     
     
         4 . The system of  claim 1 , wherein the FRC reactor burns D- 3 He, D-D, or a combination of D- 3 He and D-D. 
     
     
         5 . The system of  claim 1 , wherein the FRC reactor further comprises a closed field region containing core plasma. 
     
     
         6 . The system of  claim 5 , wherein the SOL is contained in an open field region surrounding the closed field region. 
     
     
         7 . The system of  claim 6 , wherein the FRC reactor further comprises a separatrix between the open field region and closed field region. 
     
     
         8 . The system of  claim 1 , wherein the FRC reactor further comprises neutron shielding to extract thermal energy released from the core plasma as electromagnetic radiation. 
     
     
         9 . The system of  claim 1 , wherein the FRC reactor further comprises an exhaust plume through which gas and fusion ash exit. 
     
     
         10 . The system of  claim 7 , wherein fusion ash is exhausted in less than 0.2 seconds. 
     
     
         11 . The system of  claim 1 , wherein the radius of the exit orifice ranges from 3 to 15 cm. 
     
     
         12 . The system of  claim 1 , wherein the FRC reactor is an odd-parity rotating magnetic field (RMF) reactor. 
     
     
         13 . The system of  claim 1 , wherein fusion products in the plasma decrease in speed in the SOL, allowing energy to be extracted and converted into thrust or electrical power and further allowing ash to be extracted to reduce neutron emissions and maintain high, steady-state fusion power. 
     
     
         14 . A method for widening and densifying the scrape-off layer (SOL) in a field reversed configuration (FRC) fusion reactor, comprising:
 creating a plasma in a gas box at one end of the reactor, wherein the plasma created in the gas box is cooler than both core plasma in a closed field region of the reactor and SOL plasma near a midplane of the reactor;   causing the plasma from the gas box to flow out of the gas box through an exit orifice of controllable radius and length; and   populating the SOL with the plasma that has flowed out of the gas box.   
     
     
         15 . The method of  claim 14 , wherein the plasma in the gas box has a peak electron temperature in the range 0.5-50 eV and a peak density in the range 3×10 16  cm −3  to 3×10 13  cm −3 . 
     
     
         16 . The method of  claim 14 , wherein the plasma in the SOL has a peak temperature in the range 10-200 eV and a peak density in the range 5×10 14  cm −3  to 3×10 13  cm −3 . 
     
     
         17 . The method of  claim 14 , wherein the FRC reactor burns D- 3 He, D-D, or a combination of D- 3 He and D-D. 
     
     
         18 . The method of  claim 14 , wherein the SOL is contained in an open field region surrounding the closed field region. 
     
     
         19 . The method of  claim 18 , wherein the FRC reactor further comprises a separatrix between the open field region and closed field region. 
     
     
         20 . The method of  claim 14 , wherein the FRC reactor further comprises neutron shielding, which extracts thermal energy released from the plasma, predominantly as electromagnetic radiation. 
     
     
         21 . The method of  claim 14 , further comprising exhausting gas and fusion ash out of the FRC reactor through an exhaust plume. 
     
     
         22 . The method of  claim 21 , wherein fusion ash is exhausted in less than 0.2 seconds. 
     
     
         23 . The method of  claim 14 , wherein the radius of the exit orifice ranges from 3 cm to 15 cm. 
     
     
         24 . The method of  claim 14 , wherein the FRC reactor is an odd parity rotating magnetic field (RMF) reactor. 
     
     
         25 . The method of  claim 14 , further comprising:
 decreasing speed of fusion products in the plasma in the SOL;   extracting energy from the fusion products; and   converting the energy into thrust or electrical power.   
     
     
         26 . A fusion reactor system, comprising:
 a first FRC fusion reactor, which burns D-D fuel to breed  3 He and T; and   a second FRC fusion reactor, which burns D- 3 He fuel;   wherein the bred  3 He is supplied to the first FRC fusion reactor and second FRC fusion reactor, and the bred T is transmuted to  3 He to be supplied to the second FRC fusion reactor.   
     
     
         27 . The system of  claim 26 , wherein the second FRC reactor burns D- 3 He at the ratio 1:3. 
     
     
         28 . The system of  claim 26 , wherein breeding  3 He includes exhausting  3 He and T through an exhaust plume or a gas box in the first FRC reactor. 
     
     
         29 . The system of  claim 28 , wherein breeding  3 He includes separating  3 He and T from each other and from other fusion products and SOL plasma constituents by superpermeation and/or thermal, chemical, and/or centrifugal means. 
     
     
         30 . The system of  claim 28 , wherein breeding  3 He includes separating  3 He from T through permeable membranes and/or thermal and/or chemical processes. 
     
     
         31 . The system of  claim 28 , wherein breeding  3 He further comprises transmuting T into  3 He. 
     
     
         32 . The system of  claim 26 , wherein the first reactor is located in lesser populated area and the second reactor may be located in a densely populated area. 
     
     
         33 . A method for increasing  3 He supply for use in field reversed configuration (FRC) fusion reactors, comprising:
 burning D-D fuel in a first FRC reactor, whereby burning D-D fuel breeds  3 He and T;   producing power in the first FRC reactor with the initially bred  3 He;   storing T bred in the first FRC reactor to transmute T to  3 He; and   providing the  3 He transmuted from T to the second FRC.   
     
     
         34 . The method of  claim 33 , wherein breeding  3 He includes exhausting  3 He and T through an exhaust plume in the first reactor. 
     
     
         35 . The method of  claim 34 , wherein breeding  3 He includes separating  3 He from T by superpermeation. 
     
     
         36 . The method of  claim 34 , wherein breeding  3 He includes separating  3 He from T through permeable membranes and/or thermal, chemical, and/or centrifugal processes. 
     
     
         37 . The method of  claim 33 , wherein the first reactor is located in a lesser populated area and the second reactor is located in a populated area.