50 likes | 183 Views
First idea for a quadrupole whose basic parameters could satisfy need for a larger aperture quad where QM7R sits. Cherrill Spencer, SLAC Member of ATF2 Magnet Team. What do we need to replace QM7R with? . Another quad with large enough aperture to contain both stored and extracted beams
E N D
First idea for a quadrupole whose basic parameters could satisfy need for a larger aperture quad where QM7R sits Cherrill Spencer, SLAC Member of ATF2 Magnet Team Cherrill Spencer, SLAC. ATF QM7R replacement idea
What do we need to replace QM7R with? • Another quad with large enough aperture to contain both stored and extracted beams • Extracted beam is 22mm away from stored beam, so need at least a 30mm radius aperture • Short enough to fit in longitudinal space where QM7R sits now -> QM7R is 120mm long overall • Strong enough to produce same integrated gradient as QM7R • gradient I modelled in POISSON was 213 Kg/m • Similar field quality as QM7R- is a so-called short magnet, so expect noticeable fringe field contribution to harmonics Cherrill Spencer, SLAC. ATF QM7R replacement idea
Idea- replace QM7R with a “3.15Q2.375” SLC quad Drawing shows a 3.15” (80mm) diameter, overall length ~4.5” (114mm) quad that was used in SLC and MAY be available to us. This version had solid wire coils, a water-cooled version exists Cherrill Spencer, SLAC. ATF QM7R replacement idea
Water cooled coils - a shorter version of this design. Conductor: 0.255” (6.48mm) square with 0.125” (3.175mm) diameter hole 32 turns of 0.255” square hollow copper conductor per pole. Each coil is one water circuit. Can pass more than 400 amps with a moderate LCW temperature rise. 3.15” aperture = 80mm Designed to make a Gradient of 200kG/m with 402 amps. I reckon present QM7R running at 213kG/m. Effective length= 0.10033m, so can reach required integrated strength. Cherrill Spencer, SLAC. ATF QM7R replacement idea
Have shown that a quad with the desired parameters can be designed • I just identified this “3.15Q 2.375” quad as a good candidate this afternoon. So not finished my evaluation. • Have to talk to SLAC colleagues about its availability • (are 2 of these quads in North Ring To Linac beamline of SLC, don’t know if NRTL has future use) • Not sure coils are the water cooled or solid wire version- will find out tomorrow. • Is a laminated core. Have all the drawings, could make another quadrupole with solid core & water cooled coils. • Need to look in my archived files for harmonics measurements- expect similar harmonics to present QM7R Cherrill Spencer, SLAC. ATF QM7R replacement idea