1. HRIBF Update and Near-Term
(J. R. Beene)
Fiscal year 2007 (October 2006 thru September 2007) was, in many respects, the most successful year for facility operation in the history of HRIBF. We logged 1952 hours of ISOL RIB on target for experiments out of 3648 total research hours. Out of the 1696 research hours that were not classified as ISOL RIB hours, 278 hours were "in-flight RIBS" (stable beam decay spectroscopy experiments using the RMS to select and propagate beams of radioactive species for implantation decay studies at the focal place of the RMS). Another 837 hours were stable beams provided in direct support of RIB experiments (setup tests, calibrations, etc.). Only 255 hours were devoted to stand-alone stable-beam experiments. These excellent results were achieved while keeping the IRIS2 project on schedule, and in spite of more than a month of facility shut down due to budgetary restraints and uncertainty. These are remarkable achievements for a staff under budgetary pressure, and stretched very thin. They reflect significant and ongoing improvements in facility reliability.
The period between the last newsletter and the end of the fiscal year was occupied with a very successful campaign of neutron-rich species that produced several important physics results. This was followed by a tandem tank opening in mid October, primarily to repair the gas stripper. Since that time we have been engaged in selected stable beam experiments and an extremely successful radioactive fluorine beam campaign. We plan to continue the fluorine campaign until March when we will begin a major (8 week) scheduled shutdown for maintenance. Immediately after the shutdown we plan a campaign of long-lived (batch-mode) beams (7,10Be, 26Al). If we were funded at the level of the Presidents request for FY2008, this would be followed in June by a neutron-rich campaign which would run into FY2009. Unfortunately we have recently learned that our FY2008 budget will be almost 5% below the President's request. This, coupled with increases in the cost of doing business at ORNL, will impact our ability to operate for the full year. Our initial analysis suggests a shutdown on the order of two months will be required.
The HRIBF upgrade program outlined in our Integrated Strategic Plan is now well under way and going very well. The IRIS2 is on track for completion in FY2009 (the completion date delayed by transfer of funding to later years in the last two DOE budgets). The effect of our upgrades is already being seen in improved facility performance, and we expect IRIS2 to have a further significant impact on facility efficiency and reliability. As the next step in our upgrade strategy, we will propose to add a new driver accelerator, a high power (>100kW) electron accelerator to produce neutron rich species by photo-fission in actinide targets. If such an accelerator and associated production facilities were added to HRIBF, it would increase the intensity of our most neutron-rich beams by several orders of magnitude and ensure our relevance as a RIB facility at least until a next generation U. S. rare isotope facility is fully operational. This proposal has been favorably reviewed by our Science Policy Committee and has been discussed at several workshops. The latest forum was the eRIB07 Workshop organized jointly by HRIBF and TRIUMF scientists at Newport News, Virginia in October 2007.