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A Tuning System for Spoke Cavities--Energen, Inc., 650 Suffolk Street, Suite G-03, Lowell, MA  01854-3642; 978-259-0100, www.energeninc.com 

Dr. Chad H. Joshi, Principal Investigator, joshi@energeninc.com 

Dr. Chad H. Joshi, Business Official, joshi@energeninc.com 

DOE Grant No.  DE-FG02-03ER83648

Amount:  $750,000

In continuous wave (CW) operations at facilities such as the Rare Isotope Accelerator (RIA), microphonically-induced vibration causes phase errors, and must be controlled by some form of fast-tuning.  Spoke-loaded cavities have mechanical properties which make them more suitable for mechanical fast-tuning than the currently-used elliptical-cell structures.  Based on feedback from end users, this project will design and demonstrate a compact spoke cavity tuning system.  In Phase I, a prototype fast tuning actuator, based on a patented magnetostrictive material, was completed.  In-house tests showed that the magnetostrictive actuator could perform reliably in a liquid helium environment, and the initial specifications for stroke, force, and operating frequency were achieved.  Phase II will design and build a complete fast-response tuning system that meets more stringent specifications.  In addition, a modular design will be developed for ready adaption to spoke cavities of different designs. 

Commercial Applications and Other Benefits as described by awardee:  The new tuning system should benefit those groups who are using or planning to use spoke cavities in their facilities.  The technology also should be useful in a wide range of applications that may require active vibration control.  Examples include semiconductor processing equipment and many sensitive scientific instruments, such as different types of electron microscopes or interferometers.