MANUFACTURING CONSIDERATION

1. MANUFACTURING CONSIDERATION • ECONOMIC • MANUFACTURING COST • OPERATING COST • ACCURACY AND REPEATABILITY • SPECTROMETR • TRANSPORT MAGNET • SYNCHROTRON MAGNET • RAPID CYCLING FREQURNCY • SOLID CORE • LAMINATED CORE • SOLID HOLLOW CONDUCTOR • STRANDED CONDUCTOR

3. SPECTROMETER DIPOLE IN GENERAL REQUIRE UNIFORM FIELD THROUGHOUT THE APERTURE 10-4 OR BETTER --WINDOWFRAME MAGNET --CAN BE COMPACT AND SHIMABLE TO VERY HIGH FIELD BY SHAPING THE POLES SOLID CORE 1006 OR 1010 STEEL DEPENDS ON HIGHEST FIELD REQUIRED SOLID HOLLW CONDUCTOR

4. TRANSPOT DIPOLE Reasonable accuracy for this purpose is ~10-3 Higher multipole content can be relaxed because unlike synchrotronthe beam goes through once Generally constructed with solid core, however, depending on the number of magnet, laminated core may be used Parallel or wedged ends? manufacturing consideration vertical horizontal focusing requirement

5. Wedge Horizontal focusing No focusing vertical Parallel No focusing horizontal Vertical focusing

6. SYNCHROTRON AND STORAGE RING • MULTIPOLE CONTENTS SHOULD BE MINIMIZED • ALLOWED MULTIPOLES • AT 2D DESIGN STAGE---MAXIMIZE GOOD FIELD REGEON • SHAPE THE END 3D ---THROUGH ITERATION • UNALLOWED MUTIPOLE BE ELIMINATED • MANUFACTURING ACCURACY • ACCURACY OF THE PUNCHING DIE • FLIPPING THE LAMINATION AT STACKING STAGE TO KEEP THE TWO FOLD SYMMETRY---DEVISE WAY TO ASURE THE LAMINATION FLIPPING IS DONE CORRECTLY • UNIFORMITY OF STEEL THROUGHOUT THE MAGNET • ESPECIALLY AT LOW INJECTION FIELD • IF POSSIBLE USE THE STEEL ROLLS FROM A SINGLE HEAT • SHUFFLE THE LAMINATIONS—UNIFORM DISTRIBUTION OF LAMINATIONS FROM EVERY ROLLS OF STEEL • STACK SAME LENGTH OF CORE WITH SAME WEIGHT OF STEEL

7. STORAGE RING DIPOLES • SOLID CORE MAY BE USED --- SNS • NEEDED TO BE SHIMMED • OVER 10-3 DIFFERENCE MAGNET TO MAGNET ALTHOUGH, MACHINED BY A CNC MACHINE, THERE WERE ENOUGH ERROR ALL STEELS WERE FROM SAME HEAT FROM A MILL THERE WERE ENOUGH DIFFERENCE BETWEEN TOP AND BOTTOM PART OF A LADDLE MAY CONTAIN ODD HARMONICS THE MAGNETS WERE SHIMMED ACCORDING TO THE MEASUREMENT POISSON OR OPERA ARE NOT ACCURATE ENOUGH IN TEIR PERMIABILITY TABEL HOWEVER DIFFERENTAL CALCULATION IS FEW ORDER OF MAGNITUDE BETTER

8. LAMINATED CORE • ACCURACY OF INDIVIDUAL MAGNETDEPENDS ON THAT OF CUTTING DIE • HARD TO SHIM INDIVIDUAL MAGNET • PRODUCE CONSISTENT MAGNET—COOKIE CUTTER • VERY EFFECTIVE TO ELIMINATE UMALLOWED MULTIPOLES • CONSISTENT LOW FIELD CHARACTERISTICS • EDDY CURRENT • USING LAMINATION THICKNESS DEPENDS ON REPETITION RATE • MAY USE 1006 OR EVEN 1010 STEEL FOR LOW REP RATE • GENERALLY USE Si STEEL(TRANSFORMER STEEL)FOR A HIGHER REP. RATE

9. SYNCHROTRON DIPOLE • ALL DIPOLES SHOULD BE AS IDENTICAL AS POSSIBLE • FROM LOW INJECTION FIELD TO HIGH FIELD • UNIFORMITY OF STEEL • RANDOMIZE STEEL LAMINATION PLATES • SYMMETRY IS IMPORTANT • ELIMINATE UNALLOWED ODD HARMONICS • PUNCHING DIE USUALLY IS NOT ACCURATE AND SYMMETRIC ENOUGH • THICKNESS OF STEEL COIL MAY NOT BE UNFORM • WHEN STACKING THE LAMINATIONS, NEED TO FLIP THE LAMINATIONS TO EVEN • ASYMMETRY • THICKNESS

10. 4-fold symmetry is important in construction of Synchrotron quadrupole Usually construct 4-pole block laminations should be shuffled among the steel rolls used for the uniformity the laminations are flipped in order to maintain symmetry Small notches in the back to insure proper stacking CNC machined SS steel plates are used to assemble the blocks

11. OPERA3D 로 계산한 Multipole contents ( TYPE2 경우 ) • 낮은 전류에서는 첫 번째 allowed harmonics (n=6)만 크게 보임. • 높은 전류에서는 dipole 성분이 크게 나타남. • 이는 current lead hole 때문에 위아래방향 symmetry가 깨어지기 때문인 것으로 판단됨.

12. Original geometry • Current lead hole in top side only • Asymmetric in xz plane • Modified geometry • Current lead hole in top & bottom side • Symmetric in xz plane

13. OPERA3D 로 계산한 Multipole contents ( TYPE2 경우, 400A ) • Current lead hole을 위와 동일하게 아래에도 대칭적으로 가공한 경우 (modified), symmetry가 • 회복이 되어 odd harmonics는 사라짐. • -이 경우 높은 전류에서도 dominant한 성분은 allowed harmonics인 n=6 성분임.

14. HALF OF THE ROLL SHOULD BE PUNCHED FROM THE OTHER SIDE ON THE BACK OF THE LAMINATION SHOULD HAVE IDENTIFYING NOTCHES SHOULD BE INCLUDED—FROM WHICH COIL, REVERSE ETC PROPER RANDOMIZATION COULD BE CHECKED BY LOOKING AT THE NOTCHES

15. RAPID CYCLING MAGNET AND VACUUM CHAMBER In synchrotron the vacuum chambers function not only is to contain the vacuum but also work as the shield for the circulating RF and forming co-axial current So it should have reasonable conductivity Need reasonable thickness to withstand vacuum pressure There are two problems for synchrotron due to the vacuum chamber Eddy current created multipole field Heat generated by eddy current

16. Case where one can withstand the heat Like the AGS booster the repetition rate is low enough ~10Hz and dB/dt~10T/sec stainless steel or inconnel Chamber can be used However there still is the multipole problem mainly sextupole Case of flat conducting plate chamber I I x sextupole constant

17. If one can add a current block counteracting this dB/dt Related sextupole Voltage generated by dB/dt Current driven by pole winding The eddy current generated sextupole is compensated for any rate of magnetic field rise

18. CERAMIC VACUUM CHAMBER Expensive and difficult to maintain In side surface should be coated with conductive material to prevent electron accumulation Should form a conductive cage to support counter beam RF current to flow ISIS conductive wire cage inside the chamber JPARC conductive strips outside the chamber The wire spacing should be less than the wave-length of relevant micro-wave---GHz??