In 1955, Italian Physicist Don Carlo Borghi synthesized neutrons in a
Klystron filled with hydrogen and irradiated with microwaves. Neutrons
were verified by the assorted radioactive isotopes following activation,
and their decay rates. The experiment was validated by Missfeldt in 1978
in Germany. The experiment was further validated by William Gray of
Menlo Park CA circa 2000.
Mainsteam science generally overlooks these experiments... and
especially the validation by Santilli, who actually is selling a
commercial version as a neutron generator -- but possibly the high level
rejection is for the wrong reason. The experiments were very likely
making dense hydrogen, not neutrons. UDH or ultra-dense-hydrogen has
many of the same characteristics as the neutron and can be called a
"virtual neutron". The decay mode is even similar.
Gray used a Cyclotron to energize protons to 0.78 MeV and an Electron
Gun to match their velocities, and got high yields. In its virtual
neutron state, the orbital electron travels at 2.74 x 10^8 m/s,
according to Gray - not light speed, because the proton and electron
radii limit the orbital size to 2.76 fm. Gray also fused the species
into helium. He calls this process Modulated Quantum Neutron Fusion.
Many of Gray's papers can be found at mqnf.com
Finnish theoretical physicist Matti Pitkanen discusses some of this here: