LBNL Image Library -- Collection BERKELEY-LAB/ACCELERATORS/HILAC-SUPERHILAC

modifications completed at Hilac, "crown of thorns,"

Image File

97502176

Title

modifications completed at Hilac, "crown of thorns,"

Description

"Crown of Thorns", shown with Al Ghiorso, is new first half-drift tube of the poststripper. It got its nickname from its shape and also from the headaches it gave Hilac engineers during debugging of the poststripper cavity. Spikes, or "fingers", were added to increase tube's surface area. A sweeping $1.5million modification and modernization of the Hilac-- the first major modification since it was turned on in 1957--was brought to a successful conclusion in July of 1965. The most important improvement is an increase in the duty factor (the percentage of time that the machine is actually accelerating ions) from its original 3% to a possible 100%. This means the Hilac can now operate continuously. The idea for a heavy ion machine was originated by Dr. Glen T. Seaborg and Albert Ghiorso, who conferred with Drs. E. O. Lawrence and Luis W. Alvarez. They discussed building a machine to accelerate a 'pure' beam of heavy ions (originally, nuclei of atoms up to argon-40, element 18). In part, the machine was designed jointly by UCRL (UC Radiation Lab, now LBNL) and Yale University. Mechanical engineer in charge was Hayden Gordon. Heavy ions had previously been accelerated at the 60-inch cyclotron, but could not be freed of low-energy contamination. In the Hilac, heavy ions are accelerated without interference. Experimenters at the Hilac seek to synthesize new elements and isotopes of known elements. Another experiment is “scattering” studies: in these the behavior of the struck particles gives clues to nuclear make-up. The Hilac was later modified into the SuperHILAC, and eventually became the basis for the Bevalac, which combined the SuperHILAC and the Bevatron. The SuperHilac was finally shut down on December 23, 1992.

Citation Caption

Magnet, Vol. 9, No. 8, August 1965, p. 5

Date

July 1965

People

Al Ghiorso,

TEID Doc ID

XBD9705-02176.TIF