Purdue Panel Finds Misconduct By Taleyarkhan

Well, this isn't good:

The Purdue committee, which includes representatives from other schools, said that in a follow-up paper published in 2006 in Physical Review Letters, Taleyarkhan falsely claimed that his 2002 work had been independently confirmed.

The panel also found that in a pair of 2005 papers, Taleyarkhan added another person as an author even though that researcher did not substantially contribute.

...

"From small beginnings there developed a tangled web of wishful thinking, scientific misjudgment, institutional lapses and human failings," the committee wrote. "Each strand could have been resolved separately, but knitting them together produced a crisis."

Congress Investigates Taleyarkhan

I knew that Rusi Taleyarkhan's claims of vindication were overwrought. Purdue University is pursuing a new investigation:

Three months after it cleared him of research misconduct, Purdue University has begun a new inquiry into a professor who claims to have generated nuclear fusion in a desktop experiment, the university acknowledged yesterday.

The new inquiry goes beyond the focus of an earlier one, which looked at whether the professor, Rusi P. Taleyarkhan, improperly omitted himself as an author on two scientific papers. For the first time, a committee is examining whether the underlying research might have been fraudulent.

Meanwhile, details of the earlier inquiry have emerged in a report by a Congressional subcommittee that reviewed Purdue’s actions. Although the earlier inquiry cleared Dr. Taleyarkhan of misconduct, it described “what might be characterized most favorably as severe lack of judgment” and said he had “abused his privilege as senior scientist,” according to the report from the Congressional subcommittee.

Dr. Taleyarkhan said last night in an e-mail message that the subcommittee’s report represents “a gross travesty of justice.” He asked, “Where are the Jesse Jacksons and Al Sharptons of the Asian community during this episode that has caused this biased and openly one-sided smear campaign?”

If other groups not associated with Taleyarkhan had been able to reproduce his work, we wouldn't be reading about this in the New York Times. The congressional subcommittee produced a memo that called the Purdue investigation inadequate, saying "the inquiry was not thorough and that the inquiry committee appeared to ignore the university’s definition of research misconduct", something I thought when I looked at how narrow its scope was.

Taleyarkhan Back With A Pop

Okay, so I'm stealing a bit of the New Scientist headline, but anyway, it looks like Rusi Taleyarkhan is claiming victory in his battle against charges of scientific fraud or incompentence, launched in 2002 by skeptics of his claims of creating sonofusion. Those charges were remade in 2006 by UCLA grad student Brian Naranjo, who suggested that the neutron flux Taleyarkhan was reading in fact came from improperly stored lab samples of californium. Purdue University investigated, and recently declared Taleyarkhan innocent in any wrongdoing. (Of course, this doesn't mean he isn't sloppy, and the neutrons did come from the californium.) The 2002 work has since been duplicated by Edward Forringer at LeTourneau University in Texas.

There's a much longer New York Times article on the subject with this additional material:

Critics of Dr. Taleyarkhan said other wording in the statement suggested that the university had disregarded concerns and accusations raised by non-Purdue scientists and instead had concentrated on one seemingly small issue: whether it was improper for the professor to have left his name off two scientific papers.

“The Purdue administration apparently narrowly focused the committee’s charge and avoided the question of whether the research was doctored,” said Kenneth S. Suslick, a chemistry professor at the University of Illinois at Urbana-Champaign.

The reason this is apparently important is because Taleyarkhan may have been playing fast and loose with credit in order to make it appear that the earlier alleged duplication of his results were fraudulent because the group that claimed to have reproduced them included, well, Taleyarkhan:

That appears to refer to a July 2005 announcement that two other Purdue scientists had also produced sonofusion. Dr. Taleyarkhan said this represented independent confirmation of his findings.

Others quickly questioned how independent the two scientists — Yiban Xu, a postdoctoral researcher, and Adam Butt, a graduate student — really were. Both were members of Dr. Taleyarkhan’s research group.

Dr. Taleyarkhan maintained that those experiments were performed in early 2004, before the two scientists joined his group, and that he had merely served as a consultant. (Mr. Butt did not join the group until May 2004 and did not participate in the taking of the data reported in the papers.)

Two scientific papers describing the results list Dr. Xu and Mr. Butt as authors, but not Dr. Taleyarkhan. Dr. Taleyarkhan is thanked in the acknowledgments.

If the scope of the inquiry was limited to whether it was unethical for Dr. Taleyarkhan to have left his name off the list of authors, “I guess I’m not overwhelmingly surprised that the committee decided ‘Not proved,’ ” Dr. Suslick said. “But that’s not the real issue.”

And old Taleyarkhan bête noir Seth Putterman returns to the scene:

In a paper published in Physical Review Letters, Dr. Suslick and Seth J. Putterman, a professor of physics at the University of California, Los Angeles, and another persistent critic of Dr. Taleyarkhan, said they had precisely repeated the 2002 experiment. They reported that they found none of the neutrons that would be the telltale sign of fusion and put the upper limit at just one-10,000th of what Dr. Taleyarkhan had reported.

Via Slashdot.

Update 3/2/07: Corrected the link to the NYT story above.

Californium, Here He Comes: Taleyarkhan Investigated

Thanks to John Atkinson for passing along this New York Times story that Rusi Taleyarkhan is being investigated by Purdue University for "extremely serious" concerns about his research. In particular, Brian Naranjo, a UCLA grad student, has concluded that the reports of fusion look suspiciously like the decay products of Californium:

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.

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.

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?":

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.

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."

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.

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.

Taleyarkhan's Back

Well, what the heck. It hasn't been all that long since the last time we heard from him, was it? Now in nature.com we get a dose of Rusi Taleyarkhan's latest stab at making desktop fusion a reality, which really amounts to a press release for an upcoming article he's managed to get into the peer-reviewed journal, Physical Review Letters. But just how peer-reviewed? UCLA physicist Seth Putterman, himself something of an expert in the field, wondered out loud why neither he nor University of Illinois at Urbana Champaign physicist Ken Suslick were invited to review the submission prior to publication.

Taleyarkhan says that Suslick and Putterman are welcome to visit his lab to see the results for themselves. Both are eager to go as soon as possible. "We look forward to seeing the experiment run," says Putterman.

Update 1/12: Some good discussion (and some not-so-good discussion) at Slashdot.

Purdue Researchers Reproduce Taleyarkhan Sonofusion Results

Xu and Butt

Researchers at Purdue University have reproduced sonofusion results reported by Rusi Taleyarkhan. The results, replicated by researchers Xiban Yu and Adam Butt, were published in the May issue of the peer-reviewed journal Nuclear Engineering And Design. Yu and Butt are now working with Taleyarkhan in his Oak Ridge lab, but were not prior to the publication of their paper.

Update 7/17: An article appearing in heise.de includes comments by Seth Putterman, Taleyarkhan's nemesis, who raises his earlier objection of inadequate detection:

Professor Seth Putterman from the Californian University at Los Angeles thinks, that "the data that [Xu and Butt] presented in the paper is not convincing basically for the same reason as all of Taleyarkhan's papers." Putterman demands a timed coincidence between flashes of light due to sonoluminescence and neutron measurements in a time window of a billionth of a second. Taleyarkhan's group had only shown a correlation to be within a 2 millisecond window.

IEEE Spectrum Sonofusion Article

As promised, Rusi Taleyarkhan, Richard Lahey, and Robert Nigmatulin have published an article in the May 2005 issue of IEEE Spectrum. Not much new here, though they do make the interesting claim that their apparatus makes "400 000 neutrons per second" -- a pretty bold claim, considering (a) the Spectrum is not a peer-reviewed journal, and (b) the countercharges of inadequate detection leveled by Seth Putterman. Nonetheless, the trio sounds the right note for a budding group hoping to get angel financing, saying "our experiments to date have shown that with many relatively small steps" the relatively modest (they claim a "negligible fraction of a watt of power") energy produced by their reactor could be scaled to larger devices. They also claim that following an increase of pressure in the vessel holding the deuterated acetone "from 700 kPa to 1500 kPa, we detected an increase in the neutron output by a factor of about 100 000", with "10²² neutrons per second" as the ultimate goal needed for commercial power generation. Also, they look beyond acetone, and have investigated "exotic silicon- and carbon-based liquids that can work at much higher temperatures" than acetone, which they use at 0C.

The group provides as footnotes this PowerPoint presentation, which suggests energies of 200x10⁶ K during sonocavitation are possible, and claims having recorded 10⁸ K.

At this point, I redouble my caveats -- "extraordinary claims require extraordinary proof" -- and pass on.

A Taleyarkhan Skeptic Makes His Case

Sonofusion researcher Seth Putterman, a longtime researcher into acoustic cavitation and an early pioneer of sonofusion work himself, counts himself among the skeptics of Rusi Taleyarkhan's work. Putterman ran an experiment for the BBC to test whether Taleyarkhan's most recent claims made sense:

Working from the instructions set out in Rusi Taleyarkhan's paper, it assembled the same key scientific conditions necessary to create nuclear fusion from sonoluminescence.

But to see if it could find fusion, we measured the neutrons and the flashes of light simultaneously with nanosecond accuracy, something that had never been done before.

Recording data nanosecond by nanosecond, Seth Putterman did not find a single neutron close enough to a flash of light for it to be considered the result of nuclear fusion. So the conclusion was negative.

Unfortunately, it looks like Taleyarkhan has a lot of explaining left to do, and we're no better off than we were two years ago, or ten.

Why Sonofusion Could Work

In New Scientist today (actually, dated 5 March, but who's counting?), this piece on the actual temperature inside collapsing bubbles undergoing cavitation. The problem many physicists had with sonofusion is the widespread view that individual cavitating bubbles had temperatures around 10,000 kelvin, far too low to support nuclear fusion. By contrast, the core of the sun is much hotter -- around 10M kelvin.

But the 10k kelvin figure may be misleading. Measurements of the sun's surface show it to be 7k kelvin, much lower than the temperature at the core. According to David Flannigan and Ken Suslick at the University of Illinois at Urbana-Champaign, spectra from bubbles collapsing in a sulphuric acid solution yielded light signatures from "exotic ions" such as positively charged oxygen that can only exist at temperatures of 200,000 kelvin. "Crum believes that, like the sun, the bubbles may hide even higher temperatures. 'So maybe [bubble] fusion is technically possible,' he says." Good news.

Update, 5/5: Ken Suslick, in PhysicsWeb:

"Our results are in such a different set of experimental parameters that they can neither confirm or deny Taleyarkhan’s claims to fusion," Suslick told PhysicsWeb. "A plasma is a prerequisite but certainly not a sufficient condition for fusion."

The Illinois scientists now plan to optimise cavitation and explore the conditions generated during bubble collapse. "Is inertial confinement fusion possible in a collapsing bubble? I think the verdict is still out," says Suslick. "The underlying physics is solid - it is simply a question of whether the collapse can generate a shockwave that is sufficiently intense and remains spherical long enough."

Sonofusion Researcher Winning Over Critics

In the January 22 issue, New Scientist published an article (subscription required) about sonofusion, or as its proponents now seem to prefer it be called, Acoustic Inertial Confinement Fusion (AICF). Widespread skepticism of Rusi Taleyarkhan's earlier claims seem to be melting in the face of his second paper, which used a much more methodical study of the reaction. In particular,

Instead of looking for fusion neutrons shortly after firing the initial burst, the group monitored their arrival continuously throughout the experiment. The results show that the initial burst used to seed the bubbles gradually dies down. Then, after a short time, a couple of peaks appear. These peaks, claims Taleyarkhan, are the bursts of neutrons generated in fusion reactions. "It's pretty solid evidence," says Michel Laberge, a physicist at General Fusion, a start-up in Vancouver, Canada, who also works on fusion research.

But the real beauty of the work is the control experiment that Taleyarkhan used to validate the results. He changed the timing of the initial neutron pulse, firing it when the pressure in the liquid was at its highest. Under high pressure, a bubble cannot form and so fusion cannot take place. Sure enough, the peaks that Taleyarkhan says are proof of fusion do not appear and so cannot be caused by neutrons from the initial burst. "It's very compelling data," says [UCLA researcher and Naranjo's thesis advisor Seth] Putterman.

While skeptics still abound, the new work is winning over many of his critics. DARPA plans on sponsoring a series of experiments with Taleyarkhan and some of his critics to end the debate one way or another. Things are looking up for him: another group at Purdue "led by Lefteri Tsoukalas has recreated the experiment" and will present his results in France in October.