Ivy Matt wrote:I wonder what the relative difficulty/cost of getting fusion neutrons from a Z-pinch machine is compared to getting them from a Hirsch-Farnsworth fusor. Is there any other confinement concept for which the barrier to entry is as low (or nearly so) as the fusor? (An accelerator, perhaps, but that's not really a confinement concept.)
A DPF device could also be rather small and inexpensive. The plasmoid confines itself for a very short time and can give neutron pulses:Palm top plasma focus device as a portable pulsed neutron source
Development of a palm top plasma focus device generating (5.2 ± 0.8 ) × 10^4 neutrons/pulse into 4π steradians with a pulse width of 15 ± 3 ns is reported for the first time. The weight of the system is less than 1.5 kg. The system comprises a compact capacitor bank, a triggered open air spark gap switch, and a sealed type miniature plasma focus tube. The setup is around 14 cm in diameter and 12.5 cm in length. The energy driver for the unit is a capacitor bank of four cylindrical commercially available electrolytic capacitors. Each capacitor is of 2 μF capacity, 4.5 cm in diameter, and 9.8 cm in length. The cost of each capacitor is less than US$ 10. The internal diameter and the effective length of the plasma focus unit are 2.9 cm and 5 cm, respectively. A DC to DC converter power supply powered by two rechargeable batteries charges the capacitor bank to the desired voltage and also provides a trigger pulse of −15 kV to the spark gap. The maximum energy of operation of the device is 100 J (8 μF, 5 kV, 59 kA) with deuterium gas filling pressure of 3 mbar. The neutrons have also been produced at energy as low as 36 J (3 kV) of operation. The neutron diagnostics are carried out with a bank of 3 He detectors and with a plastic scintillator detector. The device is portable, reusable, and can be operated for multiple shots with a single gas filling.