Status
- Partial replacement of old, lossy cables to RF cables
- Cable routing currently limited by available conduit space from the tunnels
- Current cable assignment documentation is incorrect and does not match assignments or installation status
- Initial waveforms taken with the Digital Analyzer were incorrectly saved and need to be re-taken
- De-embedding of RF power levels measured outside of the tunnel yields un-realistic values:
- This will be further investigated at the next shutdown which will enable tunnel access
- Yellow tags attached to tunnel power detectors do not match loss values in official drawings
- Documented losses > 10 dB off expected values for worst offenders
| Cable | Status | |
| AS1 Load FWD | 103 | Not installed |
| S Band Buncher FWD | 100 | Not installed |
| AS1 FWD | 102 | |
| AS1 REV | 104 | **Mislabelled in W0440646 as 101 |
| AS2 Load FWD | 107 | |
| S Band Buncher REV | n/a | **Mislabelled in W0440646 as 104; no cable installed |
| AS2 FWD | 106 | |
| AS2 REV | 105 | Cable damage suspected |
Data
- All data stored here
- Cable Installation document here W0440646 - PLAN - SSD2025 - Cable removal and installation for LINAC LLRF System
- Reference drawing
- LINAC tunnel 23W2495
Measurement Equipment
| Equipment | Calibration and Settings | |
|---|---|---|
Peak RF Power Meter Gigatronics 80350A/ 8652B SN:1830822/8652601 |
| Pulsed, RF triggered Validated with R&S SMA100B pulsed RF output |
Digital Serial Analyzer Tektronix DSA71254B SN:8110800 |
|
Relevant Interlocks
- KLY FWD and REV signals are connected to interlocks internal to the modulators
Setup Notes
| Signal | RF Cable from Tunnel | Tunnel Pictures |
|---|---|---|
| AS1 Load FWD | 103 (not installed) |
VIDEO DETECTOR #7 |
| S Band Buncher FWD | 100 (not installed) |
VIDEO DETECTOR #4 |
| AS1 FWD | 102 |
VIDEO DETECTOR #6 |
| AS1 REV | 101 is listed in the cable installation notes, but cable 104 is actually installed. Cable 101 does not appear to exist |
VIDEO DETECTOR #5 |
| AS2 Load FWD | 107 |
VIDEO DETECTOR #10 |
| S Band Buncher REV | According to the cable installation notes, 104. No cable actually installed |
VIDEO DETECTOR #3 |
| AS2 FWD | 106 |
VIDEO DETECTOR #9 |
| AS2 REV | 105** This cable is suspected to be damaged due to out of nominal losses at 500 MHz (27 dB) and 3 GHz (23 dB) and needs to be replaced |
VIDEO DETECTOR #8 |
| KLY1 FWD | 108 | MOD1 CP |
| KLY1 REV | 109 | MOD1 CP |
| Kly2 FWD | 112 | MOD2 CP |
| Kly2 REV | 113 | MOD2 CP |
| 125 MHZ CAV | not yet assigned | ? |
| 500 MHZ CAV | not yet assigned | ? |
| 125 MHZ DRIVER FWD | not yet assigned | ? |
| 125 MHZ CAV FWD | not yet assigned | ? |
| 125 MHZ CAV REV | not yet assigned | ? |
| 500 MHZ DRIVER FWD | not yet assigned | ? |
| 500 MHZ CAV FWD | not yet assigned | ? |
| 500 MHZ CAV REV | not yet assigned | ? |
RF Power Level Calculations
Notes: These calculated de-embedded values are not consistently physically realistic; do not use these for any analysis or purpose.
Noted here as the investigation continues to determine the sources of errors in drawings and documentation.
| Total Peak Power Summary | |||
| Peak Power Measurement at Rack | Peak Power in Tunnel, De-embedded | ||
| dBm | dBm | MW | |
| AS1 Load FWD | 6.8 | 109.9 | 97.3 |
| S Band Buncher FWD | 10.4 | 103.1 | 20.6 |
| AS1 FWD | 8.4 | 111.6 | 145.9 |
| AS1 REV | -16.6 | 73.0 | 0.020 |
| AS2 Load FWD | 4.9 | 110.8 | 119.9 |
| S Band Buncher REV | -14.9 | 61.9 | 0.002 |
| AS2 FWD | 10.4 | 113.5 | 225.4 |
| AS2 REV | 4.2 | 100.8 | 12.1 |
| Losses | |||||||
| RF Tunnel to Rack Cable Loss | Coupler cf | Installed Atten | Internal Cable Loss+Atten (per Tag) | Tag Total | Drawing Loss + Coupling Total | Total Loss + cf in Peak power Measurement used for de-embedding | |
| dB | dB | dB | dB | dB | dB | dB | |
| AS1 Load FWD | 16.83 | 53.26 | 33 | 32.99 | 86.25 | 83.82 | 103.08 |
| S Band Buncher FWD | 16.13 | 50.34 | 26 | 26.26 | 76.6 | 76.8 | 92.73 |
| AS1 FWD | 17 | 53.26 | 33 | 32.98 | 86.24 | 84.19 | 103.24 |
| AS1 REV | 16.13 | 53.26 | 20 | 20.24 | 73.5 | 71.44 | 89.63 |
| AS2 Load FWD | 19.87 | 53.2 | 33 | 32.82 | 86.02 | 83.82 | 105.89 |
| S Band Buncher REV | 16.13 | 50.34 | 10 | 10.26 | 60.6 | 60.8 | 76.73 |
| AS2 FWD | 16.83 | 53.2 | 33 | 33.1 | 86.3 | 84.05 | 103.13 |
| AS2 REV | 23.15 | 53.26 | 20 | 20.2 | 73.46 | 73.46 | 96.61 |
