Transcript LCLS Injector Overview D. H. Dowell, SLAC FAC Review April

L0-1 Design, Manufacturing & Testing
R. F. Boyce, SLAC
RF Technical Review, November 3, 2004
L0-1 Design Specifications
Engineering Constraints and Assumptions
Engineering Drawings of New Input Cells
Detail of RT geometry
Dual feed assembly
Fabrication Process
Tuning the New Cells
Tuning the Dual Input High Power RF Circuit
Schedule
Summary and Conclusions
3 November 2004
Injector UpdateL0-1 Accelerator Structure
1
Richard F Boyce
[email protected]
L0-1 RF Design Specifications
Coupler Design For The LCLS Injector L0-1 Structure
Zenghai Li, Lynn D. Bentson, David H. Dowell,
Cecile Limborg, John Schmerge, Liling Xiao
LCLS Technical Report, in progress
3 November 2004
Injector UpdateL0-1 Accelerator Structure
2
Richard F Boyce
[email protected]
Engineering Constraints and
Assumptions
Dual RF Input Feed (eliminates dipole kick)
Race Track Design (eliminates quadrupole
field)
Solenoid has to fit over RF flanges and
supports
Modify an existing SLAC structure
Cut off two cells and replace with new coupler
assembly
3 November 2004
Injector UpdateL0-1 Accelerator Structure
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Richard F Boyce
[email protected]
Dual Feed Parts:
Race track cell and adjacent cell
SLAC Drawing PF-380-804-09
67.335
A
.55mm
O 101
3.998in
29.132
5.842
O
O 92.08
O 92.13
O 83.3 0.7874
R 3.0861
A
13mm
.512in
O 26.21
O 101.549
R 3.0861
.68mm
O 71
2.822in
SECTION A-A
3 November 2004
Injector UpdateL0-1 Accelerator Structure
71.68mm
2.822in
4
Richard F Boyce
[email protected]
Constraints on the Dimensions of the Solenoid
8.687 Outer radius
O 7.126
Inner diameter
36.505
Length
C
3 November 2004
Injector UpdateL0-1 Accelerator Structure
C
5
Richard F Boyce
[email protected]
Procedure for Cutting Existing Structure
In 1985 Carl Rago shortened structures from 10 feet to 9 ½ feet as shown on
SLAC Drawing SA-750-214-02
Cut the structure
between the
irises and
machine the end
back to the iris
3 November 2004
Injector UpdateL0-1 Accelerator Structure
Their cuts
6
Richard F Boyce
[email protected]
Our cut
New Coupler Assembly
Mating features will be
identical to those used for the
9 ½ foot shortened structures.
Location of braze points
for the tuning studs.
Mating surface to braze
to the modified structure.
3 November 2004
Injector UpdateL0-1 Accelerator Structure
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Richard F Boyce
[email protected]
Fabrication Process
Fabricate the parts and cut the existing structure
Cold RF test of parts before brazing dual feed sub
assembly
Re-machine parts as required, iterate with cold
tests
Braze dual feed subassembly
Cold test brazed subassembly with cut structure
Final braze of subassembly to cut structure
Final RF tests
3 November 2004
Injector UpdateL0-1 Accelerator Structure
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Richard F Boyce
[email protected]
Tuning the L0-1 Structure
Proposed design with push-pull studs
NLC design using slide hammer studs
Standard SLAC technique using hydraulic
pinch
3 November 2004
Injector UpdateL0-1 Accelerator Structure
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Richard F Boyce
[email protected]
Proposed L0-1 Tuning Studs
The studs are brazed to the wall of
the cell and captured by a hollow
adjusting screw which is turned in or
out for the adjustment process.
Stud
Hollow
screw
Threaded
housing
All tuning parts are stainless
steel with silver plated threads
3 November 2004
Injector UpdateL0-1 Accelerator Structure
Braze to
copper cell
DETAIL I
10
Richard F Boyce
[email protected]
NLC Standard HDDS Cell Tuning
The tuning stud is
attached to a slide
hammer for the
adjustment process
3 November 2004
Injector UpdateL0-1 Accelerator Structure
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Richard F Boyce
[email protected]
Tuning of a Standard SLAC Structure
A hydraulic press was moved to each cell and pinched it
according to a well know process.
This was done as part of a mass production procedure.
3 November 2004
Injector UpdateL0-1 Accelerator Structure
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Richard F Boyce
[email protected]
Dual Feed RF High Power RF Circuit
Directional
Couplers
Pumps
Supports
Dual input feeds are balanced on the bench and the Directional Coupler
signals are recorded and documented for future checks.
3 November 2004
Injector UpdateL0-1 Accelerator Structure
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Richard F Boyce
[email protected]
Tolerances on Dual Feed Waveguide and
Coupling Holes
Table 1 The tolerance for the four coupler errors is listed. The tolerance is determined by
either reducing the amplitude to 1% of its nominal value or the phase to 10% of its nominal
value as listed in the last column.
Error
Coupler Position
Coupler Iris Size
RF Feed Amplitude
RF Feed Phase
Tolerance
 < 1°
D/D0 < .02
V/V0 < .02
 < 3°
Defining Criteria
Phase
Amplitude
Amplitude
Phase
Coupler Design For The LCLS Injector L0-1 Structure
Zenghai Li, Lynn D. Bentson, David H. Dowell,
Cecile Limborg, John Schmerge, Liling Xiao
LCLS Technical Report, in progress
3 November 2004
Injector UpdateL0-1 Accelerator Structure
14
Richard F Boyce
[email protected]
LCLS Injector and Linac Schedule
Gun and L0-1 needed for installation:
October 2006
3 November 2004
Injector UpdateL0-1 Accelerator Structure
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Richard F Boyce
[email protected]
Summary and Conclusions
L0-1 accelerator section
RF design finished
Engineering design in progress
Manufacturing processes are being researched
Completed accelerator section needed for
October 2006 installation
3 November 2004
Injector UpdateL0-1 Accelerator Structure
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Richard F Boyce
[email protected]