MBA Magnets MultiBend Achromat Magnets 8/14/2015 Review By Mark Jaski

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 2

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 3 Leakage field 10 Gauss Bubble

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 4 ~25 cm away from coils Leakage field 10 Gauss Bubble

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 5 Add shield plates

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 6 Add shield plates

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 7 Add shield plates 10 Gauss Bubble

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 8 15 mm thick shield plate Add shield plates 10 Gauss Bubble

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 9 10 mm thick shield plate Add shield plates 10 Gauss Bubble

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 10 5 mm thick shield plate Add shield plates 10 Gauss Bubble

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 11 Add additional shield plates

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 12 Add additional shield plates 10 Gauss Bubble

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 13 Add additional shield plates 10 Gauss Bubble

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 14 Add shield plates the full length

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 15 Add shield plates the full length 10 Gauss Bubble

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 16 Add shield plates the full length 10 Gauss Bubble

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group mm mm Q2 end Q3 begin Required position of M1 Magnet center 0.894° Plotted from M. Borland Excel V6 lattice file with drifts.

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 18 cm Insertion length Minimum good field region (~6 mm) Simulated electron trajectory vertex US_angle cm Magnet center 0.90 cm Simulated position of M1

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group mm wide poles. Shown is bottom half with beam trajectory.

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 20 Adjustable shield gap Tuning the integrated field with constant current by adjusting the gap of the end shields. Top view of high field end. Make the insertion length 4 mm shorter to compensate for the vertex movement from the shield adjustment. 10 Gauss bubble has negligible change when moving shields 10 mm on high field end. 26 mm shield gap 46 mm shield gap gap 26 mm46 mm

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 21 Field Plot Sharp field corners because of shields

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 22 Integral-in-z field plot vs x Gauss-cm cm Beam

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 23 Multipole Errors compare 26 and 27 mm gaps Multipoles are slightly better for 27 mm gap most likely because 26 mm gap is not fully optimized. 27 mm gap requires ~150 W more power. 27 mm gap should be acceptable.

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 24 Plot of b 0 multipole error as a function of s

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 25 Plot of b 1 multipole error as a function of s

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 26 Plot of b 2 multipole error as a function of s

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 27 Vacuum chamber interface

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 28 Tuning coils and pole lengths are sized such that the first and second integrals do not change when tuning coils are energized (+/-10 A). Optional tuning coils to vary the length of the electron beam through the L-bend. Field plot when tuning coils are energized to 10.0, 0.0 and A. Field (T) Z (m) L-bend shown without side shield. -10 A 0.0 A 10 A

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 29 From Q2-end to vertex to Q3-begin is mm mm mm mm mm mm Q2 end Q3 begin Simulated trajectory length 13 microns total adjustment Vertex

7/2015 Alternative L-Bend Mark Jaski Accelerator Systems Division Magnetic Devices Group 30

7/2015 Alternative L-Bend  All results presented are preliminary.  It appears a 27 mm gap, requested by the vacuum group, can be used.  End and side shields (skirt) are needed to reduce the leakage field.  End shields can be made adjustable to individually tune the integrated field (the first integral) on each magnet. –Is +/- 0.13% enough? –Insertion length need to be made shorter (~4 mm) to accommodate vertex position change from tuning.  Optional tuning coils are available. –Second integral tuning coils (presented in a previous presentation). –S-length tuning. –A first integral tuning coil could be added but has not been studied. Mark Jaski Accelerator Systems Division Magnetic Devices Group 31