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1. HRIBF Update and Near-Term Schedule
(J. R. Beene)

The funding outlook for FY 2011 is much more uncertain than it appeared when the last edition of this newsletter was drafted. The outlook for FY 2012 appears even more uncertain. However, we have had a period of strongly enhanced funding since the extended FY 2009 continuing resolution ended. This has enabled us to begin our long-planned staffing enhancement (see my update article in the February 2010 Newsletter) and to enhance our spare parts and maintenance materials inventory after several years of operation with badly depleted inventories. This should substantially improve our ability to respond rapidly to equipment failures. In addition, the IRIS2 project is now complete and awaiting ORIC beam for commissioning. The enhanced facility efficiency due to the availability of a second RIB production station, plus the new beam production and purification capabilities that IRIS2 will enable us to deploy, will have a dramatic impact on HRIBF operations.

We have been unable to operate ORIC reliably since the nine-month enforced shutdown that followed the July 2008 Operational Emergency. Consequently, we have been unable to launch an extended neutron-rich RIB campaign. In February 2010, one of the ten ORIC trimming coils failed. Previous trimming coil failures occurred in 1986 and 1997. The most recent failure left us with only seven operational coils (see ORIC Operations and Development for details). We were unable to operate ORIC successfully in this configuration, so the decision was made to install the replacement set of trimming coils fabricated after the second coil failure in 1997. We expect this installation to be complete in early November, 2010.

While the work on ORIC was ongoing, we provided radioactive beams of four long-lived species (7Be, 10Be, 26Al and 82Sr) to user experiments. We have also carried out stable-beam runs, almost exclusively in support of the PAC-approved RIB experimental program. Only about 300 hours of stand-alone stable beam experiments were run.

Kate Jones and her collaborators are to be congratulated on a high profile paper on the Magic Nature of 132Sn published in Nature [1] during the period covered by this newsletter. Nature provided a commentary on this work written by Paul Cottle of Florida State University in the News and Views section of the same issue. More details about the public interests generated by this paper is summarized by Witek Nazarewicz in this issue of the Newsletter.

Another high-profile result was the discovery of a new superheavy element with atomic number Z=117 by a US-Russian collaboration that included a HRIBF scientist, Krzysztof Rykaczewski, as a key member [2]. The experiment was made possible by a target prepared with 249Bk material made at the ORNL High Flux Isotopes Reactor, and separated by ORNL chemists. This result was featured on the cover of the April 9 issue of Physical Review Letters. More details about this experiment is described by Krzysztof in a separate article in this Newsletter.

On August 2-6, HRIBF hosted the Ninth Summer School on Exotic Beam Physics under the leadership of Michael Smith and Caroline Nesaraja. More details about this very successful Summer School is given by Michael in this Newsletter.

On May 17, 18 and 19 DOE held an Operations Review of HRIBF. We have not yet received a final report from this review; however, in the closeout session strong concern was expressed about the negative impact of ORIC reliability on the HRIBF science program. The preliminary indication at the closeout was that the sole recommendation of the review would be that HRIBF hold an additional review with a panel of cyclotron experts focusing exclusively on ORIC, and including a deeper investigation into ongoing ORIC maintenance as well as possible future reliability and performance improvements. After further consultation with DOE Office of Nuclear Physics, we have scheduled this intensive ORIC review in the last half of August. HRIBF staff looks forward to the opportunity to discuss issues related to ORIC in more detail, and to profit from outside expertise. The only regret is that this review will deal only with ORIC, and will not consider the many advantages of replacing ORIC with a commercial cyclotron (see the article on the HRIBF driver upgrade in the February 2009 Newsletter, and the report on the HRIBF User Workshop in the February 2010 Newsletter).

The near-term schedule at HRIBF will be constrained by the trimming coil assembly replacement, which is expected to extend through October. The schedule from now to October will be filled with experiments using long-lived radioactive beams along with stable beam runs in support for RIB experiments. We anticipate very few stand-alone stable beam experiments will be scheduled. A tandem tank opening is scheduled to begin in October and last for seven weeks. Before the tank opening is complete, we intend to have ORIC operational. When the tank opening is complete, we plan to initiate an extended neutron-rich RIB campaign that will run well into CY 2011.

References:

1. K. Jones, et al., Nature 465, 454 (2010).
2. Yu. Ogannessian, et al., Phys Rev. Lett. 104, 142502 (2010).



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