Xband Accelerating Structures Review Brazing and Bonding Manifolds

X-band Accelerating Structures Review Brazing and Bonding Manifolds Assembly Dmitry Gudkov BE/RF

Contents § Accelerating structures with manifolds. Damping waveguides manifolds. § Assembly of accelerating structure disks stack and manifolds Accelerating Structures Review § Brazing test § Results § Alternative production methods § References

Damping Waveguides Manifolds Accelerating Structures with Manifolds Accelerating structures with damping waveguide manifolds: 94 TD 26 CLEX Oleksiy Kononenko TD 24 R 05 Si. C The manifolds are used to house Si. C damping material and vacuum ports: Vacuum port Si. C damping material CLEX Accelerating Structures Review Example: RF design of TD 26 AS

Assembly of Accelerating Structure Disks Stack and Manifolds Assembly of the disks stack and manifolds is performed by brazing; Contact – cylindrical surface; Pin is used for positioning of the manifold on the disks stack; 4 manifolds are brazed in two steps. 1 st step – horizontal manifolds; 2 nd – vertical manifolds; § Different forms of brazing alloy can be chosen; § Brazing test was performed in order to choose the best alloy configuration. Accelerating Structures Review § § Serge Lebet, Vadim Soldatov

Brazing test § 4 configurations of brazing materials are tested; § Bonded stack of simplified disks is used (simplified iris); Accelerating Structures Review § All the tolerances relevant for assembly are respected; § Stack is cut in 4 octants by EDM; § Each octant is brazed with manifold with use of different configuration of brazing material; § After brazing the specimens are prepared for ultrasound test; § Ultrasound test is performed; § Results analysis; § Additional inspections; § Conclusions.

Brazing test Straightness measurements after bonding Manifold geometry Accelerating Structures Review Standard CLIC bonding of simplified disks See next slid for measurements results. The manifolds are produced by milling

Brazing test N 2 N 3 N 4 1. Brazing shim (t = 0. 05 mm) with pockets geometry equal to damping waveguides 2. Brazing shim (t = 0. 05 mm) with single pocket 3. Brazing wire Ø 0. 7 mm 4. Brazing shim (t = 0. 076 mm) with single pocket 0. 008 mm misalignment between the disks 0. 014 mm misalignment between the disks 0. 005 mm misalignment between the disks 0. 014 mm misalignment between the disks Accelerating Structures Review N 1 Brazing alloy Au 50/Cu 50

Brazing test After brazing the specimens are cut (8 mm max thickness is required for ultrasound test) Accelerating Structures Review brazing Au 50/Cu 50 820 ᴼC cutting inspection Serge Lebet, Ana Teresa Perez Fontenla

Results Ultrasound inspection N 2 N 3 N 4 1. Brazing shim (t = 0. 05 mm) with pockets geometry equal to damping waveguides 2. Brazing shim (t = 0. 05 mm) with single pocket 3. Brazing wire Ø 0. 7 mm 4. Brazing shim (t = 0. 076 mm) with single pocket Accelerating Structures Review N 1 Ana Teresa Perez Fontenla

Results Microscope inspection N 2 N 3 N 4 1. Brazing shim (t = 0. 05 mm) with pockets geometry equal to damping waveguides 2. Brazing shim (t = 0. 05 mm) with single pocket 3. Brazing wire Ø 0. 7 mm 4. Brazing shim (t = 0. 076 mm) with single pocket Gaps No gaps Accelerating Structures Review N 1 Ana Teresa Perez Fontenla

Accelerating Structures Review Results § Specimen #3 • The best result of ultrasound test is for the specimen #3 (wire form of brazing material); • Additional cutting is made to confirm the good joint in the area between two damping waveguides; • No gaps or discontinuities were found between rectangular waveguide pockets; § Specimen #4 • Good results are achieved for specimen #4 (Brazing shim t = 0. 076 mm with single pocket); • No gaps or discontinuities were found between rectangular waveguide pockets; • The misalignment between disks for specimen #4 (0. 014 mm) is bigger than #3 (0. 005 mm). § Specimens #1 and #2, • The ultrasound scan shows several defect indications (in green and red color). Worse results were on the specimen #2. • To confirm the origin of the defects the cutting and metallographic preparation was done. By microscope observation (optical and digital microscopy) the gaps up to 70 um between manifold and the stack are confirmed. Ana Teresa Perez Fontenla

Alternative Production Methods One of the alternatives to manifolds is the integrated version disk. The following advantages comparing to design with manifolds: • Accelerating Structures Review • • • Total number of parts in the assembly is reduced; Total number of assembly operations is reduced; Total assembly accuracy is increased; Risk of braze filler material inside the structure is reduced; Cooling channels can be integrated to disks; Total number of brazing cycles is reduced; Possible cost reduction. Study is under way

References 1. EDMS 1301361 v. 1 Integrated version disks review of manufacturing strategies; 2. EDMS 1301117 v. 1 Integrated version disk. Test program; Accelerating Structures Review 3. EDMS 1340537 v. 1 US test on Cu-OFE structure after brazing test of manifolds and disc stack; 4. EDMS 1305838 v. 1 US test on three Cu-OFE structures after brazing test of manifolds and disc stack; 5. EDMS 1336797 v. 1 UT inspection of brazing test of manifold to stack of discs. Brazing foil 0. 076 mm without windows;