Fusion Physics Energy Boon or Nuclear Gloom

1
Fusion Physics - Energy Boon or Nuclear Gloom?

• David Schilter and Shivani Sharma

2
Problem Statements...

• Is it possible to construct a potential array
  (electrostatic potential well) which would allow
  for resulting energy close to or exceeding
  applied voltage?
• What electrode configuration in an IEC device can
  both avoid energy loss due to space charge as
  well as encouraging ion acceleration?
• Would the idea of circulating ions provide a
  solution to the problems of space charge while
  also inducing nuclear fusion?

3
Plasmas

• AC grid causes radio frequency discharge which
  creates oscillating B and E ? ionizes the
  hydrogen gas used to create a plasma, a mixture
  of high energy ions and electrons
• Diffuses into a chamber that also contains a
  neutral hydrogen background gas, which is not
  affected by the electrodes

4
Experimental Setup

• Inner spectacle (?22mm) ? cathode
• Outer mesh ? anode (earthed)
• Pressure maintained at 5mTorr (7x10-6 atm)
• Magnetic field was set at 70 gauss (7x10-3 T)
• Voltages of 1-10kV applied to cathode

5
Electrode Geometry
6
Some theory...

• The H? line (656.3nm) represents the first atomic
  transition in the Balmer series (from n3 to n2)
• 1/? RH(1/2)2 - (1/n)2 where
  Rydbergs constant RH 1.0968x107m-1
• The spectrometer measures intensity near this
  wavelength, providing a wavelength distribution.
• Fusion cross-section (probability) of 1H is many
  orders of magnitude less than deuterium (2H) or
  tritium (3H)

7
Charge-exchange Reactions

• Charge exchange reactions occur as fast, ionized
  plasma collides with stationary background gas
• In all cases, the high energy plasma becomes
  unstable due to the exchange and fragments
• This results in the excited radical H which is
  detected by the spectrometer

• H H?H H
• H2 H ? H H H
• H3 H ? H H2 H
• H H2? H H2
• H2 H2 ? H H H2
• H3 H2 ? H H2 H2

8
Observations

• Very slight circulation of ions observed between
  two rings, which were red hot
• Majority of ions passed through, and continued in
  a roughly linear path, which created beams
• Purple colour characteristic of high energy
  hydrogen

9
Energy Distributions

• Shifts involved are characteristic of the various
  charge-exchange reactions
• The knee relates to the most energetic ions
• Intense alpha line is due to background gas
• Note symmetry?ions moving toward and away from
  spectrometer

10
Results Continued...

• Energy plotted against voltage results in a
  linear relationship
• It was also found that that B had no effect on
  the maximum ion energies
• Efficiencygradient, which in this case is
  approximately 7

11
Conclusions

• Excited and Doppler shifted atoms were observed
  at wavelength up to 0.89nm greater than that of
  the H? line (?o656.3nm) corresponding to
  energies of 8.7x10-1keV
• Efficiency of 7 clearly too low?new grid design
• B not strong enough to induce circulation in a
  large proportion of the ions
• Ions accelerated from each direction rather than
  in a circular motion to avoid the virtual anode
• The simulation of the exact same conditions were
  undertaken and discrepancies accounted for...