We, the undersigned plasma physicists, are familiar with magnetic mirror research, and we are concerned about the recent actions of the administration of the University of Tsukuba in Japan. Teruji Cho, a professor there, was dismissed from his position as director of the university’s plasma research center on 6 March 2008, allegedly for intentionally manipulating experimental data that appeared in Physical Review Letters. 1 That publication, in fact, contains results that are extremely interesting and far-reaching in their significance. Cho’s team definitively demonstrated that flow shear stabilization can be directly controlled using off-axis electron cyclotron resonance heating. In addition to the dismissal, the university requested that the PRL editorial staff retract the paper.

The accusation against Cho, and against three other senior staff members, was initiated by graduate students who filed a complaint to an administrative oversight committee that was headed by Hiroshi Mizubayashi. After an investigation, the committee demanded of Cho that the PRL paper be retracted. An additional university investigatory committee headed by Kazuhiko Shimizu supported that demand. However, Cho and his senior collaborators refused to make such a retraction because they are convinced of the integrity of their data. They submitted to the university committee a report addressing the controversial issues, and they submitted to the journal Physics of Plasmas (PoP) a more detailed paper for publication. The university committees rejected Cho’s report without substantive scientific comments.

Meanwhile, Cho’s manuscript was judged to be scientifically sound and to merit publication in PoP 2 on the basis of favorable standard refereeing and reports from two additional experts who were consulted when the PoP editorial staff became aware of the scientific controversy associated with Cho’s work. We believe that the PoP editors acted correctly; the second paper convincingly confirms the correctness and reliability of the results published in the PRL paper. However, the university administration apparently did not accept the opinion of the PoP editorial board. Instead, they terminated Cho’s professorial position on 29 August 2008, an action that was announced in the worldwide press.

Many scientists who are familiar with magnetic mirror research, especially that conducted at Tsukuba’s plasma research center, are deeply concerned about the accusations against Cho and his colleagues. At least four letters have been sent to Yoichi Iwasaki, president of the university, to inform the administration of support for the scientific integrity of Cho’s claims. None of those letters were acknowledged. We find it troubling that the university appears to be uninterested in the opinions of experts in the field.

It is clear to us that neither Cho nor his close colleagues on the GAMMA-10 team intentionally misrepresented data. We cannot understand why the University of Tsukuba administration has taken the extreme action of dismissing a distinguished investigator. Cho has been open about his experimental and analytical techniques and has shared his data and methodology with his research team and with foreign collaborators from Russia and the US. We are concerned that the university’s actions against Cho constitute a form of scientific censorship. We believe that an appropriate international scientific panel should investigate the university’s behavior in this matter.

T. Choet al,
Phys. Rev. Lett.
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Phys. Plasmas