Pyroelectric Fusion - Results Since 2005

Results Since 2005

In April 2005 a UCLA team headed by the Distinguished Professor of Chemistry and Fellow of the Royal Society James K. Gimzewski and Professor of Physics Seth Putterman utilized a tungsten probe attached to a pyroelectric crystal in order to increase the electric field strength. Brian Naranjo, a graduate student working on his Ph.D. degree under Putterman, conducted the experiment demonstrating the use of a pyroelectric power source for producing fusion on a laboratory bench top device. The device used a lithium tantalate (LiTaO₃) pyroelectric crystal to ionize deuterium atoms and to accelerate the deuterons towards a stationary erbium dideuteride (ErD₂) target. Around 1000 fusion reactions per second took place, each resulting in the production of an 820 keV helium-3 nucleus and a 2.45 MeV neutron. The team anticipates applications of the device as a neutron generator or possibly in microthrusters for space propulsion.

A team at Rensselaer Polytechnic Institute, led by Dr. Yaron Danon and his graduate student Jeffrey Geuther, improved upon the UCLA experiments using a device with two pyroelectric crystals and capable of operating at non-cryogenic temperatures.

Nuclear D-D fusion driven by pyroelectric crystals was proposed by Naranjo and Putterman in 2002. It was also discussed by Brownridge and Shafroth in 2004. The possibility of using pyroelectric crystals in a neutron production device (by D-D fusion) was proposed in a conference paper by Geuther and Danon in 2004 and later in a publication discussing electron and ion acceleration by pyroelectric crystals. None of these later authors had prior knowledge of the earlier 1997 experimental work conducted by Dougar Jabon, Fedorovich, and Samsonenko. The key ingredient of using a tungsten needle to produce sufficient ion beam current for use with a pyroelectric crystal power supply was first demonstrated in the 2005 Nature paper, although in a broader context tungsten emitter tips have been used as ion sources in other applications for many years. In 2010 it was found that tungsten emitter tips are not necessary to increase the acceleration potential of pyroelectric crystals; the acceleration potential can allow positive ions to reach kinetic energies between 300 and 310 keV.

Pyroelectric fusion has been hyped in the news media, which has overlooked the earlier experimental work of Dougar Jabon, Fedorovich and Samsonenk. Pyroelectric fusion is not related to the earlier claims of fusion reactions, having been observed during sonoluminescence (bubble fusion) experiments conducted under the direction of Dr. Rusi P. Taleyarkhan of Purdue University. In fact, Naranjo of the UCLA team has been one of the main critics of these earlier prospective fusion claims from Taleyarkhan.

The first successful results with pyroelectric fusion using a tritiated target was reported in 2010. The UCLA team of Putterman and Naranjo worked with Dr. T. Venhaus of Los Alamos National Laboratory to measure a 14.1 MeV neutron signal far above background. This was a natural extension of the earlier work with deuterated targets.

In late 2012 an idea was proposed by a Mr A de Guerin on various forums suggesting that a variant of "bubble fusion" may be able to generate X-rays if a sonoluminescence cell was to be built using two or more near UV 395nm "burner lasers" focussed on the bubble. This approach would allow fine tuning of the wavefront during compression allowing an order of magnitude increase in the speed of collapse. As a result the energy density could increase substantially representing a temperature approaching 3 million degrees K and possibly higher if optical feedback via a high speed camera was also used.

This paper has not yet been published however from feedback on the same forum it appears that it "looks promising" and may be a completely novel approach to low yield neutron production.