Californium, Here He Comes: Taleyarkhan Investigated
Instead, Mr. Naranjo said that the pattern of particles seen in the experiment much more closely matched that given off by californium, a radioactive element that is used in Dr. Taleyarkhan's laboratory. With $350,000 from the Defense Department, Seth J. Putterman, a professor of physics at U.C.L.A. and the thesis adviser to Mr. Naranjo, has tried to build a replica of Dr. Taleyarkhan's apparatus and has not seen any signs of fusion.Update 3/8: Nature has more on this, including the actual paper (PDF) on Naranjo's UCLA website. That publication has another couple of articles on the topic, including "Is Bubble Fusion Simply Hot Air?":
Dr. Putterman said he told Dr. Taleyarkhan of the calculations last week on a visit to Purdue. "He didn't have any clear answers," Dr. Putterman said. "From my perspective, his answers were not satisfactory."
Californium is present in Dr. Taleyarkhan's laboratory, stored in a closet about 15 feet from the experiment — close enough to generate the results reported in Dr. Taleyarkhan's paper if it had been stored improperly.
In late 2003, [Purdue University factulty member Lefteri] Tsoukalas managed to lure Taleyarkhan away from his position at Oak Ridge National Laboratory in Tennessee, and in the spring of 2004 Taleyarkhan arrived full-time at Purdue. By this time, the team had completed several experimental runs, but had not seen any evidence for bubble fusion.It gets worse: earlier claims that others had reproduced his earlier results appear to have been published in a non-refereed journal, a special issue of Nuclear Engineering and Design that was edited by Taleyarkhan himself. Tsoukalas, who had been unable to reproduce Taleyarkhan's results but declined to publish his findings at Taleyarkhan's request, is now pressing forward with their release in Nuclear Technology. Taleyarkhan also removed lab equipment without which it was "very difficult to triple-check our results", according to Tsoukalas.
Once Taleyarkhan had arrived, lab members became increasingly concerned by his actions. Jevremovic says that he would sometimes examine the equipment and claim that it was producing positive results, referring to an oscilloscope that he had. She says that she was uncertain about how the oscilloscope fitted into the experiment so she asked him for the raw data, but never received any. "He said: 'Look, there's a peak', but there was nothing to see," she says. "I started questioning it."
Finally, Nature has a summary article, whose concluding paragraph reads,
And the US Department of Energy, for whom Taleyarkhan was working when he first reported his claims, has abandoned its patent application relating to bubble fusion, after the patent office said it would throw it out last year (see 'A sound investment?'). .
Taken together, the overall message from many people close to this work is that there is no longer any hope that this line of publications will yield a viable fusion energy source. For some this is almost liberating: those sticking with bubble fusion are freer than ever to explore other approaches to it, or to try other kinds of studies on acoustic chambers and the behaviour of collapsing bubbles. For others it is now the end of bubble fusion. There are other kinds of science to be done.