1. Results of short module and qualification strategy
PIMS production meeting February 2013
Rolf Wegner

2. Production qualification, April 2012
Status of machining qualification, :
Step
std + central disc
end disc (cooling ch.)
ring by milling
ring by turning
WG-ring
1st rough (+2mm)
ok ( )
ok ( )
brazing test => horizontal or vertical brazing ?
2nd rough (+1mm) ok
( )
Ring G_13-14: serious non-conformities => repair of EB-weld
Ring G_1-2: serious non-conformities => machining tests
3rd rough (+0.2mm),
final
Full Quality Assurance Report + check at CERN
PIMS production meeting February Rolf Wegner

3. Review of steps towards qualification
Meeting at CERN in March 2012:
* machining procedures optimised (=> clamping) [parts seen 5 to 10 times out of tolerance]
* specifications very tight; small performance degradation <=> accepting certain deviations from specifications (EDMS )
* recommendation: final machining on a lathe
Meeting at NCBJ in April 2012:
* green light for rough machining of discs for series
* Quality Assurance Report form defined
Mai 2012:
* new weld qualification with cosmetic pass + repair of weld for ring G_13-14
* preliminary metrology end disc M_1 => green light to finish end disc M_14 and disc M_6-7
June 2012:
* brazing test finished
PIMS production meeting February Rolf Wegner

4. Review of steps towards qualification
July 2012:
* QA report disc G_2-3 ok, end disc M_1 ok, shipment to CERN
* QA report disc M_6-7, re-machining of assembly ø524 requested
* QA report end disc M_14, agreed on adaptation of ring M_ side 14 for assembly ø524
September 2012:
* welding of ring M_13-14 ok, defect on ring M_1-2 => sent for repair to Julich => using ring G_13-14 as 2nd ring for short module
* brazing test evaluated at CERN (visual inspection, ultrasound & vacuum tests), very good result, => green light to produce waveguide ring cavity M
* disc G_2-3, end disc M_1 inspected at CERN => green light for finishing all discs cavity M
November 2012:
* QA report ring M_13-14
PIMS production meeting February Rolf Wegner

5. Review of steps towards qualification
December 2012:
* QA report re-machined ring G_13-14 => green light for finishing all rings cavity M
* end disc M_14, disc M_6-7, ring M_13-14 and ring G_13-14 arrived at CERN
January 2013:
* QA report discs M_2-3, M_12-13
February 2013:
* QA report discs M_4-5, M_10-11
PIMS production meeting February Rolf Wegner

6. Quality Assurance Reports
=> "Disc G_2-3 - Analysis & Comparison CERN.xlsx"
* report form from NCBJ exactly as desired
* analysis to specifications
* analysis to acceptable dimensions
* comparison to CERN measurements
metrology machine accuracy: ± 6 μm
=> comparison precision: ± 12 μm
=> specifications 500 mm ± 10 μm difficult to machine and difficult to measure !!!
results quite similar (a few small points to discuss tomorrow)
PIMS production meeting February Rolf Wegner

7. PIMS production meeting 26-27 February 2013 Rolf Wegner
Vacuum tests at CERN
end discs M_1, M_14; disc G_2-3; ring M_13-14 all leak rate < 2*10-11 mbar*l/s
PIMS production meeting February Rolf Wegner

8. PIMS production meeting 26-27 February 2013 Rolf Wegner
Brazing test at NCBJ
good visual impression
vacuum tight (leak rate <1*10^-10 mbar l/sec)
good ultrasound analyse results
Agostino: ”It is hard to do it better”
=> Green light for brazing of WG ring of 1st cavity ( )
PIMS production meeting February Rolf Wegner

9. Machined parts, end discs M_1 and M_14
element
EDMS
remarks
slight deviations*
serious deviations*
where
leak tight
cavity suited
end disc M_1
surf. roughness <0.8
Ø524: gap +16 μm
cooling channels (wall >5.0mm)
survey hole 1 8H mm but NCBJ and CERN metrology deviate ≤ 54 μm
none
CERN
yes
yes,
ready
end disc M_14
scratches, craters
⌾Ø518: +33 μm
nose position: +10 μm
Ø524: gap -31 μm => adjacent ring opened by 30 μm
some holes too short ( mm)
⌾Ø524: +74 μm
tbd,
* to acceptable dimensions
PIMS production meeting February Rolf Wegner

10. Machined parts, disc M_6-7
element
EDMS
remarks
slight deviations*
serious deviations*
where
leak tight
cavity suited
disc M_6-7
scratches, craters
⌾Ø518: +43 μm / +16 μm
Ø524: gap -5 μm / 57 μm
⌾Ø524: +20 μm / 26 μm
Ø538: +25 μm / + 23 μm
nose length: -5 μm / +12 μm
nose position: +19 μm / 35 μm
coupling slot symmetry & R15
cooling channels (wall >5.0mm)
surf. roughness nose cone 1.0 to 2.8 μm side 7
burrs on all cooling channels => to be re- machined
CERN
* to acceptable dimensions
PIMS production meeting February Rolf Wegner

11. Machined parts, ring M_13-14
element
EDMS
remarks
slight deviations*
serious deviations*
where
leak tight
cavity suited
ring M_
side 14 well opened for end disc M_14
circularity / 0.08 with 2 max/min
⌾Ø538: +2 μm / +19 μm
surf. roughness inside μm => 1.2% more RF losses
⌾Ø524: +51 μm / μm
CERN
YES
tbd,
ready
* to acceptable dimensions
PIMS production meeting February Rolf Wegner

12. Machined parts, disc G_2-3
element
EDMS
remarks
slight deviations*
serious deviations*
where
leak tight
cavity suited
disc G_2-3
surf. roughness <0.8
Ø538: +23 μm / + 19 μm
nose length: +18 μm
flatness nose tip: 47 μm
CERN
YES
YES,
ready
* to acceptable dimensions
PIMS production meeting February Rolf Wegner

13. Machined parts, ring G_13-14
element
EDMS
remarks
slight deviations*
serious deviations*
where
leak tight
cavity suited
ring G_13-14
machining tests
many
welds: 87 μm / 75 μm
B⊥A: (0.3 all cavity)
NCBJ no
but ok for short module
* to acceptable dimensions
Ring G_13-14 was intended for machining tests to validate milling technology (spare material of CERN prototype)
port welding defect, weld was repaired, further machining tests
port welding defect of ring M_1-2, ring G_13-14 is used for assembly check of short module
PIMS production meeting February Rolf Wegner

14. Machined parts, summary
discs analysed are close to acceptable dimensions => remarkable progress made since last year (improvement of factor 5 to 10 on most tolerances) assembly diameter seem to be well under control (QA reports discs M_2-3, M_4-5, M_10-11, M_12-13) however, deviations on * coaxiality axis/524/538mm (=> inter-cavity alignment – aperture reduction) * perpendicularity axis/faces (=> inter-cavity alignment – aperture reduction) * cooling channel finishing
=> we need to analyse remaining discs of cavity M at CERN for qualification
ring M_13-14 is close to acceptable dimensions => remarkable progress made since last year (machining procedures were developed [weld deformation] and most acceptable tolerances reached) assembly diameter seem to be well under control (also ring G_13-14) however, deviations on * coaxiality 538/524mm (=> inter-cavity alignment – aperture reduction) * perpendicularity axis/faces (=> inter-cavity alignment – aperture reduction) * only 1 ring as sample
=> we need to analyse remaining rings of cavity M at CERN for qualification
PIMS production meeting February Rolf Wegner

15. Short module: assembly test
end disc M_1
ring G_13-14
disc G_2-3
ring M_13-14
end disc M_14
assembly was very smooth
only end disc M_14 was slightly difficult to place correctly, small gap remains => Thierry will use dense point weldings before final weld
PIMS production meeting February Rolf Wegner

16. Short module: RF check, preliminary results
measured
simulated
freq. difference [kHz]
ratio meas/sim [%]
f_mode_1 [MHz]
-744
Q_mode_1
21'500
26'560
80.9
f_mode_2 [MHz]
-662
Q_mode_2
27'730
30'200
91.8
z-axis: assembly order z=0 end disc M_1 - ring G_ disc G_2-3 - ring M_ end disc M_14 … to z=max
PIMS production meeting February Rolf Wegner

17. Short module: RF check, preliminary results
measured
simulated
freq. difference [kHz]
ratio meas/sim [%]
f_mode_1 [MHz]
-744
Q_mode_1
21'500
26'560
80.9
f_mode_2 [MHz]
-662
Q_mode_2
27'730
30'200
91.8
assembly had to be clamped, otherwise Q ~ 1'000, f_mode_1 ~ MHz
Q-values reasonable, will improve with welding (~ 10% seen for prototype)
field profiles look very similar, slight deviations for mode 2
~ 700 kHz frequency difference between measurement and simulations
simulation uncertainty ~ ± 500 kHz (mesh limit, 2 cells, different geometry)
tuning range (island + plunger) for mechanical tolerances + simulation uncertainties: ± 600 kHz
=> further analysis needed to understand difference in frequency simulations/measurement
=> simulation model needs to be checked carefully (systematic difference 700 kHz)
PIMS production meeting February Rolf Wegner

18. PIMS production meeting 26-27 February 2013 Rolf Wegner
Next steps
qualification of vacuum check
* visit of NCBJ experts to CERN, March 25-26th, tests of end disc, disc, ring
* shipment of equipment to NCBJ (~ 100 kg, ~ 200 pieces, ~ 25'000 CHF)
* visit to NCBJ with CERN experts, intended before April 19th (material !) tests of end disc, disc, ring
vacuum check of discs and rings cavity M at NCBJ
production and checks of waveguide ring cavity M at NCBJ
check of discs and rings cavity M at CERN => qualification for series production
check of waveguide ring cavity M at CERN => qualification for series production
in order to advance production, maybe intermediate green light for finishing cavity 2
PIMS production meeting February Rolf Wegner

19. Production qualification, February 2013
Status of qualifications, :
Step
std + central discs
end discs
rings
WG-rings
1st rough (+2mm)
ok ( )
ok ( )
ok ( )
2nd rough (+1mm) ok
( )
ok ( )
final for cavity 1 (M)
( )
( )
final for cavity 2
vacuum check at NCBJ
final for series
check discs cavity 1 (M) at CERN
check rings cavity 1 (M) at CERN
check WG-ring cavity 1 (M) at CERN
PIMS production meeting February Rolf Wegner