Patent Number: 
Section: claims

1. A method for production of radioisotopes, the method comprising:directing a light pulse along an optical axis to generate a quasi-neutral plasma jet in the absence of an electromagnetic accelerator; anddirecting, in the absence of an electromagnetic accelerator, the quasi-neutral plasma jet in a direction collinear with the optical axis onto a radionuclide precursor. 2. The method of claim 1, where the quasi-neutral plasma jet is produced by impinging a light pulse less than about 10−11 seconds in duration onto a target material;wherein the dimensionless vector potential of the light pulse, αo,=0.6λ √I, is greater than about one, where λ is the wavelength in μm and I is the intensity in units of 1018 W/cm2. 3. The method of claim 2, where the target material is a solid film or particle; or the target material is a liquid film, jet, or droplet. 4. The method of claim 2, where the target material is a gas jet whose number density in the focal region of the light pulse is greater than about 1020 nuclei per cubic centimeter. 5. The method of claim 2, where the light pulse is preceded by one or more pre-pulses whose dimensionless vector potential αo<10−4. 6. The method of claim 2, where the light pulse is produced by a laser having a wavelength of about 0.4 μm to about 20 μm. 7. The method of claim 2, where the light pulse is preceded by one or more pre-pulses whose dimensionless vector potential αo<10−10. 8. The method for production of radioisotopes, comprising:generating a quasi-neutral plasma jet; anddirecting the quasi-neutral plasma jet onto a radionuclide precursor,where the quasi neutral plasma jet passes from an evacuated region through a window to interact with the radionuclide precursor at a region of higher pressure. 9. The method of claim 8, whereinthe evacuated region is at a pressure of 37 Pascal (Pa) or less; andthe region of higher pressure is at a pressure of about 100 kPa to about 10 MPa. 10. The method of claim 8, wherein the region of higher pressure is at a pressure of about 100 kPa. 11. The method of claim 8, where the window material has an average atomic number less than about 14 and thickness small enough to ensure >90% transparency to the plasma jet. 12. The method of claim 8, wherein the window has a thickness of about 0.1 millimeter to about 0.5 mm. 13. The method of claim 8, where the window material has an elastic modulus of greater than 1 GPa. 14. The method of claim 8, wherein the window material supports the pressure of the high pressure region with less than about 1% strain. 15. The method of claim 8, where the window material comprises poly-paraphenylene terephthalamide (Kevlar) or poly-p-phenylene benzo-bis-oxazole (Zylon). 16. The method of claim 8, where the radionuclide precursor is a liquid contained in a channel or capillary of a microfluidic reactor. 17. The method for production of radioisotopes, comprising:generating a quasi-neutral plasma jet; anddirecting the quasi-neutral plasma jet onto a radionuclide precursor,where the energy distribution of the ions in the quasi-neutral plasma jet, f(E), is chosen to maximize the rate of radioisotope production for a process with a cross-section Q(E) according to the formula:            ⅆ              [        RN        ]                    ⅆ      t        =            [      Precursor      ]        *          ∫                        Q          ⁡                      (            E            )                          *                  f          ⁡                      (            E            )                          *                  v          ⁡                      (            E            )                          ⁢                  ⅆ          E                    where [RN] is the concentration of radionuclide, [Precursor] is the concentration of precursor, and ν(E) is the center-of-mass velocity for the nuclear reaction that converts Precursor to RN. 18. The method of claim 17, wherein the energy distribution f(E) is a monotonically decreasing function of energy. 19. The method of claim 17, wherein the concentration of precursor is 1020 cm−3 or greater.