A. Castañeda 07 th September 2009 Generators and Detectors Permit Loop / CIBG / CIBO 0v0.
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A. Castañeda 07 th September 2009 Generators and Detectors Permit Loop / CIBG / CIBO 0v0
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Transcript of A. Castañeda 07 th September 2009 Generators and Detectors Permit Loop / CIBG / CIBO 0v0.
A. Castañeda 07 th September 2009
Generators and DetectorsPermit Loop / CIBG / CIBO
0v0
Summary
● Brief Summary about Permit Loops
● Beam Permit Loop Frequency Generator (CIBG)
● Optical Transceiver (CIBO)
Generators and Detectors 2 of 19
Permit Loops
● A single generator is used in the whole loop● The frequency is not regenerated at any point ● Avoid failures that could force the permit loop to be maintained
regardless of the actual state of the USER_PERMIT signals.● Frequencies chosen 8 – 10 MHZ
– Allow rapid response.– Not harmonics with any known frequency in any CERN accelerator.
● In the case of the LHC:– One loop anticlockwise (A) and One loop clockwise (B)
– A : 9.375 MHz / B: 8.375– The signal is repeated 18 times and travels aprox 45 kms.
Generators and Detectors 5 of 19
Beam Permit Loop General Layout
Generators and Detectors 6 of 19
B
A
● CIBG is responsible for the generation of the BEAM_PERMIT freq.● Any USER_SYSTEM can break the frequency loop through a
USER_PERMIT triggered to the corresponding Beam Interlock Controller.
● If the frequency appears at the end BEAM_PERMIT TRUE● In the LHC Reaction time ~ 120 μ s
CIBG – Frequency characteristics
Generators and Detectors 11 of 19
● Output frequency accuracy:
Test freq
CIBG – Frequency characteristics
Generators and Detectors 12 of 19
● Input frequency accuracy:– Slow detector (Nominally A: 9.375 MHz / B: 8.375 MHz)
- It activates when the integrity of the optical link degrades over time.- It counts the number of edges sent in several hundred microseconds.- Slow detect: ± 5% error / Measures takes 100 ms.- And compares to the following boundaries.
CIBG – Frequency characteristics
Generators and Detectors 13 of 19
● Input frequency accuracy:– Fast detector (Nominally A: 9.375 MHz / B: 8.375 MHz)
– It observes the link for a few 100ths of ns.– Detects the change in link state due to a real request for Beam Dump– Fast detect : ± 10% error / Measures takes 3-4 μs.
CIBG – Additional Information
● You can find all detailed schematics, pcb layouts and electrical characteristics about the CIBO in sections #12 and #16 of the folder provided .
Generators and Detectors 14 of 19
[email protected], the LHC and Machine Protection 17 of 19
CIBO – Block diagram
TTL
-36 to -39 dBm Sensitivity
No Effect Maintenance False Dump Blind Failure
1.96833 x 10-7 0 8.29872 x 10-7 3.428 x 10-9
CIBO P(Fail) per Hour
-15 to -25 dBm Output
1310 nm Singlemode
CIBO – Additional Information
Generators and Detectors 18 of 19
● You can find all detailed schematics, pcb layouts and electrical characteristics about the CIBO in sections #20 of the folder provided.
