TD24 R05 N1 after high-power test analysis plans A. Degiovanni, M. Aicheler, N. Mouriz Irazabal, A.T. Perez Fontenla, R. Wegner CLIC RF Structure Development Meeting 23/04/2014
Jan 02, 2016
TD24 R05 N1 after high-power test analysis plans
A. Degiovanni, M. Aicheler, N. Mouriz Irazabal, A.T. Perez Fontenla, R. Wegner
CLIC RF Structure Development Meeting23/04/2014
2
Outline
• History of the structure: EDMS: 1258457 – traveller of structure EDMS: 1239394 – RF tuning (22-24.08.2012, Vasim+Rolf) EDMS: 1306038 – post high power operation analysis
• Observations: detuning of coupling cells (last cell frequency decrease, opposite to T(D)18) hot cell developed during high power operations ( Wilfrid’s analysis)
• What needs to be done?1. metrology measurements (for better understanding detuning effect)2. hot cells analysis (BD distribution)3. B-arc features (EDMS: 1096980, TD18 KEK/SLAC post mortem observations)4. samples (octant/quadrant) for collaborators
• Possible cutting methods• Proposal(s) for TD24
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3
Cells nomenclature1: input coupler
26: output coupler
5
2: first regular cell 25: last
regular cell
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Cells nb.8h. Records nb.
time3
8
13
18
23
1
5
TD24R05 normalized BD distribution
Hot cells (5 and 6) have appeared from record #50The very high peak values are an artifact of the normalization (if only 2 BDs during a record these cells will result very active)
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5
Comparison of Beadpull measurements
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5 10 15 20 25
-2
-1
0
cell number
Re(
S11
,loca
l) [%
]
Analysis of S11,local
, calculated by Jiaru's tuning program
5 10 15 20 25
-4
-2
0
2
cell number
Im(S
11,lo
cal)
[%]
5 10 15 20 250
2
4
cell number
|S11
,loca
l| [%
]
2012 before HPO
2013 after HPOdifference
Re coupling;little changes
Im detuning;strong 25,26;some 1,2
Preliminary RF measurements analysis of TD24 from CLEX, Rolf Wegner, 14.08.2013
Comparison of detuning of different structures
T18 SLAC N1 TD18 SLAC T24 SLAC T18 CERN N2 TD24 CLEX TD24 R05 N1
XBox1
Analysed at SLAC SLAC SLAC CERN CERN CERN
by J.W. J.W. J.W. J.S. R.W. R.W.
Output matching
Standing Wave (VSWR) 1.06 1.22 1.05 1.11 1.05 1.15
R [%] 3.0 10 2.5 5.0 2.6 7.0R [dB] -30 -20 -32 -26 -32 -23
dfend [MHz] +2.0 +7.0 +2.5 +3.0 +0.1 -2.2
dfend-1 [MHz] +1.0 +1.7
Regular cells
Total phase shift [°] -16 6 -9.2 ~ -6
avg(df) [MHz] +1.0 -0.3 +0.4 +0.2
std(df) [MHz] +0.2 +0.3
notes Dj19®20 ~ 100° Dj19®20 ~ 100° Dj19®20 ~ 100° structure retuned
Rolf Wegner
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7
Cutting methods
Turning and ripping apartMilling and groovingAbrasive saw cutting
Water-jet cutting
Wire Electrical Discharge Machining (EDM)
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Sawing
8
Cutting methodsCutting method Cutting issues Indicated
for type… Example
1 Saw
High deformationHigh velocity chips and pollution* into the cavity(*The pollution due to cooling liquids could be reduced or even suppressed)
damped TD18KEK/SLAC
22.a Milling-2.b Turning (and ripping
apart)
Very clean method (for undamped only)Possible small deformation
undamped T18 KEK/SLAC
3
Wire EDM cut
(Electrical Discharge
Machining)
No deformationSparks in the cutting plane and possible oxidation;Pollution into the cavity (de-ionized water)
Damped/ undamped T18 CERN
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Cutting methodsCutting method Cutting issues Indicated
for type… Example Metrology check
BD distribution
on iris
SEM chemical analysis
Detailed SEM
exploration
1 Saw
High deformationHigh velocity chips and pollution* into the cavity(*The pollution due to cooling liquids could be reduced or even suppressed)
damped TD18KEK/SLAC no difficult difficult difficult
22.a Milling-2.b Turning (and ripping
apart)
Very clean method (for undamped only)Possible small deformation
undamped T18 KEK/SLAC limited yes yes yes
3
Wire EDM cut
(Electrical Discharge
Machining)
No deformationSparks in the cutting plane and possible oxidation;Pollution into the cavity (de-ionized water)
Damped/ undamped T18 CERN yes yes no
could be affected by pollution
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Cutting methodsCutting method Cutting issues Indicated
for type… Example Metrology check
BD distribution
on iris
SEM chemical analysis
Detailed SEM
exploration
1 Saw
High deformationHigh velocity chips and pollution* into the cavity(*The pollution due to cooling liquids could be reduced or even suppressed)
damped TD18KEK/SLAC no difficult difficult difficult
22.a Milling-2.b Turning (and ripping
apart)
Very clean method (for undamped only)Possible small deformation
undamped T18 KEK/SLAC limited yes yes yes
3
Wire EDM cut
(Electrical Discharge
Machining)
No deformationSparks in the cutting plane and possible oxidation;Pollution into the cavity (de-ionized water)
Damped/ undamped T18 CERN yes yes no
could be affected by pollution
4Abrasive saw slow cutting
Slow rotation speed implies long time (~days)«clean» methodNo deformation
Damped/ undamped
Never done before
Aquistion of suitable
machine...
yes yes maybe maybe
5 Water jet cutting
No deformationPollution into the cavity
Damped/ undamped
Never done before yes yes no
could be affected by pollution
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11
Cutting issues
• copper-air transition due to the damping waveguides• iris thickness + holes for dimple tuners• length of the structure for rotating support• …
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12
5
Overall cutting scheme for TD24• Remove the flanges• transverse cutting of the two extremities• longitudinal cut for metrology of input and output coupler• slicing of cells number 4-5-6&21-22-23 for iris inspection • (cut of central cells 12-14 and metrology check for comparison with couplers)
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13
5
Cutting scheme 1 for TD241. Remove the flanges by EDM2. transverse cutting of the two extremities by EDM3. longitudinal cut for metrology of input and output coupler by EDM4. slicing of cells number 4-5-6&21-22-23 for iris inspection by EDM5. (cut of central cells 12-14 as for step 2 and 3)
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14
5
Cutting scheme 2 for TD241. Remove the flanges by mechanical sawing2. transverse cutting of the two extremities by mechanical sawing3. longitudinal cut for metrology of input and output coupler by EDM4. slicing of cells number 4-5-6&21-22-23 for iris inspection by mechanical sawing5. (cut of central cells 12-14 as for step 2 and 3)
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15
5
Cutting scheme 3 for TD241. Remove the flanges by mechanical sawing2. transverse cutting of the two extremities by milling/turning and ripping apart3. longitudinal cut for metrology of input and output coupler by EDM4. slicing of cells number 4-5-6&21-22-23 for iris inspection by milling/turning and ripping apart5. (cut of central cells 12-14 as for step 2 and 3)
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16
5
Cutting scheme 4 for TD241. Remove the flanges by mechanical sawing2. transverse cutting of the two extremities by abrasive low speed sawing3. longitudinal cut for metrology of input and output coupler by EDM4. slicing of cells number 4-5-6&21-22-23 for iris inspection by abrasive low speed sawing5. (cut of central cells 12-14 as for step 2 and 3)
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Conclusion and discussion• Desired measurements:
– Metrology on input and output coupler to better understand the observed frequency shift– BD distribution on cell 5 and adjacents to find and locate possible hot spot– other possible surface exploration and analyses (also samples to collaborators)
• Four proposed options to be chosen from
• Do we want to study the option of a low speed abrasive saw?• Do we want to study the option of the water jet cutting?
STEP option 1 option 2 option 3 option 4
1 removing the flanges EDM mech.
sawingmech. sawing
mech. sawing
2 transverse cutting EDM mech.
sawingmilling/turning
abrasive slow sawing
3 longitudinal cutting EDM EDM EDM EDM
4 slicing of cells 4-5-6&21-22-23 EDM mech.
sawingmilling/turning
abrasive slow sawing
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https://edms.cern.ch/file/1093645/2/CLIAAS120079_-_ASSEMBLY.pdf
TD24_vg1.8_R05
input ports
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https://edms.cern.ch/file/1093645/2/CLIAAS120077_-_STANDARD_CELL.pdf
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