1. SRF Frequency data flow (focus on elliptical)
Cecilia Maiano, Karol Kasprzak, (and Enrico for the data!)
9th SRF Collaboration Meeting, ESS
2018/11/06

2. ID Installation Structure
Frequency data at ESS
Following requirements for long term maintenance plan of facility
ESS Scope
IKC
After fabrication
Intermediate handover
Outgoing
Measurement&Calibration DB
(ownCloud service)
ESS Asset Management
ID Installation Structure
Live Staging Area
(WFT files)
Transfer
Tagging (in metadata)
Script
Save
APPLICATIONS
Browse
Compare
Assess
Normalized Data
(HDF files, metadata)
ESS
Incoming
Preparation TS2/Linac
Script

3. Transfer not yet in place during MECCTD!
Data sent in excel file by Enrico
We used it for populating the C&M DB and develop the application framework
Parsed
to WFT
&
Normalized
to HDF
All data in ESS C&M DB
(...)

4. Goal: Confirm design assumptions and VT experience
Global check during all phases of MECCTD lifecyle
With the history loaded in DB we practiced at ESS the checks that we plan to perform starting from incoming inspection at ESS up to tunnel operation
We can also review the experience to confirm the assumptions used for the frequency preparation strategy, which were practiced during the fabrication and VT testing of the prototype cavities
Freeze the comparison criteria for frequency acceptance and handover
See Paolo presentation later
Let’s have a look at the data

5. Cavity M001/LASA In position 1 of the module: 18 Measured Spectra
Just to show all measurements…
Difficult to assess visually the “goodness”

6. Cavity M001/LASA
In position 1 of the module: Pi mode shift during operations
4K to 2K
Cool to 4K
Load Tuner( reset)
OUT IN
Vessel
Vac Tank
(tuner)
Vac Tank
(bracket)
Bracket
Important info for activities at ESS

7. Cavity M001/LASA In position 1 of the module: Coupling factor
LASA cavity is 1.7% (higher than CEA design)

8. Cavity M001/LASA In position 1 of the module: Spectral deviation
???
Unreliable measurement?
Not enough accuracy or error
If not all modes are measured, no mse
20 KHz

9. Cavity MP04/CEA
In position 2 of the module: Pi mode shifts during operations
Ouch!
High…
OUT IN
Vacuum
(tuner)
Vacuum
(bracket)
Cavity known to be softer (excessive BCP)
ALSO: Bracket too soft for assessment?

10. Cavity MP04/CEA In position 2 of the module: Coupling factor
Just to remind that CEA cavity is 1.3%

11. Cavity MP04/CEA
In position 2 of the module: Spectral deviation
20 KHz

12. Cavity MP01/CEA
In position 3 of the module: Pi mode shifts during operations
OUT IN
Vacuum
(tuner)
Vacuum
(bracket)
(as before …)

13. Cavity MP01/CEA
In position 3 of the module: Spectral deviation
20 KHz

14. MP02/CEA In position 4 of the module: 18 Measured Spectra Orange: BAD!
Green: BAD!

15. MP02/CEA In position 4 of the module: Pi mode shift during operations
OUT IN
Vacuum
(tuner)
Vacuum
(bracket)
(as before …)

16. MP02/CEA In position 4 of the module: Spectral deviation
Orange: BAD!
* Referring to colors in the spectra
Confirms that two measurements have bad data!
Green: BAD!

17. Summary From the above data we can derive the following data
Parameter, all data kHz
CAV1
M001
CAV2
MP04
CAV3
MP01
CAV4
MP02
<AVE>
SPREAD
Effect of Brackets (also, hysteresis due to mechanical slack) 70
165
107
112
114±48
From string in vacuum, VV&tank PA, to 4.2 K
1186
1181
1169
1150
1172±18
From string in vacuum, VV&tank PA, to 2K
1103
1107
1091
1080
1095±14
4.2K to 2K, col, (Pressure sensitivity 1 bar to 30 mbar )
-83
-74
-78
-70
-76±7
String from air to vacuum (tuner, tank & vv air, RT)
174
177
190
195
184±11
Vessel from air to vacuum (tuner, string vacuum, tank air, RT)
111
105 75
99±18
Data fairly stable, to be used during TS2/Tunnel preparation phases
T data not available for all measurements (approx. 5 kHz/C around RT)
In line with assumptions for cavity fabrication, will update ESS

18. Conclusions and outlook
Way forward
Please use automated measurements as much as possible
Insufficent quality of data and manual transcription operation leads to inability to verify
We are ready to receive files
We need to deploy a data infrastructure for consolidation (later on) in the asset management database, following ESS top requirements
We do no enforce any format, we are interested only in consistency (use any given template for all production) and data quality (automation!)
We will take care of the translation and normalization, not on your workload
Transfer for now either by or shared repositories (no sophisticated tool)
May happen later if ICS provides support, but number of cavities is still reasonable to handle this way
We have a (minimal) framework for data analysis
Limits: Script-based, on the ESS internal network, do not expect fancy GUI, they will come later or never
Will seek ICS help to allow use from outside and friendliness (maybe moving to our Jupiterhub)
All this can be shared, just ask us