bonding and brazing sequence (based on accelerating ......pressure application td24 pressure...

X-band Accelerating structure Review 1 24-25 NOVEMBER 2014

Bonding and brazing sequence (based on accelerating structures TD26 CC and TD24)

Serge Lebet and Anastasiya Solodko


Drawings TD26 CC TD24 KEK


Environment

• Assembly of the structures are done in air-conditioned room with air-filtering which corresponds to a «salle blanche».

• The room is equipped with leak detector of H2 and of N2


Thermal cycles

Brazing of the couplers

Machining of interfaces for RF flanges

1st brazing of cooling circuits

Brazing of RF flanges

Preparation of discs for bonding

Alignment measurements of disc stacks before bonding

Difussion bonding

Alignment measurements after bonding

Brazing of tuning studs, vacuum tubes and vacuum flanges

Brazing of cooling circuits

Leak tightness test

RF measurements and tuning

Vacuum baking

Structure Components Numbers of

heating cycles

TD24 Couplers 4

Discs 3

TD26 CC

CC waveguides 5

Input/output cells 5

Discs 3


Requirements

Temperature ~ 1040 °C; Time ~ 1,5 h; Vacuum 10-6 mbar; H2 partial pressure 20 mbar; Applied pressure 0.1 MPa; 3 thermocouples; Witness discs for pollution analysis

Bonding oven (outside)

Bonding oven (inside) all molybdenum

Temperature profile

Bonding requirements


Assembly process • Assembly in V-shape column • Straightness and tilt measurements before bonding • Weight application • Bonding • Straightness and tilt measurement after bonding

Pro

cess

Eq

uip

me

nt

• V-shape column • Measurement column • Tooling for the weight application • Graphite/ceramic pads

Straightness measurements before and after bonding

Equipment

Bonding procedure


Brazing requirements:

High temperature (depends on the brazing alloy); Time a few minutes; Vacuum 10-6 mbar; H2 partial pressure 20 mbar.

Au/Cu 25%/75% 1040 °C

Au/Cu 35%/65% 1020 °C

Au/Cu 50%/50% 980 °C

Brazing material (configuration):

Paste; Wire; Shim; Plating.

Brazing material (composition):

Au/Cu; Ag/Cu/Pd.

MO

ST U

SED

Brazing requirements


First step: outgassing of the bonding/brazing tooling at 1100 °C

• Ceramic pad • Graphyte pad • Tooling bonding • Etc…

Outgassing of the tooling


Brazing of coupleurs (body & cover)

3. Brazing of compact coupler waveguides TD26 CC

2. Brazing of couplers TD24 1. 1st brazing of cooling circuits

Au/Cu 25%/75% 1040 °C


Machining of couplers

Machining of compact coupler waveguides TD26 CC

Machining of coupleurs TD24

Machining of interfaces for the RF flange


Bonding input / output cells TD26 CC

Bonding of output/input cells TD26 CC


Brazing of couplers & RF flanges Brazing of output/input cells,

CC waveguides and RF flanges TD26 CC

(assembly before brazing)

Brazing of couplers, vacuum and RF flanges TD24

(assembly before brazing)

Au/Cu 25%/75% 1040 °C


Alignment tools

Column Mitutoyo 600mm (1.1 + 0.6L µm)

Camera Vision

Equipment for: - straightness measurement of disc stacks; - measurement of external diameter of discs; - angular positioning of discs using a reference line.

Comparator (±0.5 µm) with gage blocks


Straightness measurement before bonding

Straightness measurement before bonding TD24

Straightness measurement before bonding TD26 CC


Pressure application

TC1

TC3

TC2 30 kg

28 kg

Pressure application 0.1 MPa P= F/S

Pressure application TD24 Pressure application TD26 CC

3 Thermocouples

Witness discs


Straightness measurements after bonding

16

Measurement 1

Measurement 2

Measurement 3

Measurement 4

Measurement 6

Measurement 5 22

2 m

m

Engr

aved

are

a Starting height 5 mm, length 222 mm, step 8.3 mm (1 point per disc)

5 mm


Straightness measurements

Straightness measurements for the disc stacks of accelerating structures have been done before and after bonding:

• Before bonding, measurements have been done for two generatrices because

of the position of the structure in the v-shape column, the position of the tooling and the position of engraved numbers.

• After bonding, measurements have been done for six generatrices.


Brazing of tuning studs

Fixed by ceramic studs

Brazing of tuning studs TD26 CC Brazing of tuning studs TD24

Au/Cu 35%/65% 1020 °C


Brazing of cooling circuits

Brazing of cooling circuits TD26 CC Brazing of cooling circuits TD24

Au/Cu 50%/50% 980 °C


Leak tightness test TD26 CC TD24


RF measurements and tuning TD26 CC TD24

…see B. Woolley presentation on 25.11.2014 Session “Established procedures and Quality assurance”


Vacuum baking

CERN oven now is equipped with an gas analyser

Requirements

Temperature 650 °C; Time 10 days; Total time ~ 15 days; Vacuum 10-9 mbar.

…see M. Taborelli presentation on 25.11.2014 Session “Established procedures and Quality assurance”

Packaging and shipping


TD26 CLEX superstructure

One TD26 CLEX structure is currently under test in CLEX. The second SAS is supposed to be installed in January 2015.

A superstructure (two AS brazed together);

4 waveguides with WFM; Compact couplers; Vacuum manifolds; SiC absorbers.

bonding and brazing sequence (based on accelerating ......pressure application td24 pressure...

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