1. A. Castañeda 07 th September 2009 Generators and Detectors Permit Loop / CIBG / CIBO 0v0

2. alejandro.castaneda.serra@cern.ch Summary ● Brief Summary about Permit Loops ● Beam Permit Loop Frequency Generator (CIBG) ● Optical Transceiver (CIBO) Generators and Detectors 2 of 19

3. alejandro.castaneda.serra@cern.ch BRIEF SUMMARY ABOUT BEAM PERMIT LOOPS Generators and Detectors 3 of 19

4. alejandro.castaneda.serra@cern.ch Permit Loops Generators and Detectors 4 of 19

5. alejandro.castaneda.serra@cern.ch 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

6. alejandro.castaneda.serra@cern.ch 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

7. alejandro.castaneda.serra@cern.ch CIBG (Beam Permit Loop Frequency Generator card) Generators and Detectors 7 of 19

8. alejandro.castaneda.serra@cern.ch CIBG – I/O Generators and Detectors 8 of 19

9. alejandro.castaneda.serra@cern.ch CIBG – Hardware Implementation Generators and Detectors 9 of 19

10. alejandro.castaneda.serra@cern.ch CPLD GENERATOR CIRCUITS Generators and Detectors 10 of 19 Tx Rx

11. alejandro.castaneda.serra@cern.ch CIBG – Frequency characteristics Generators and Detectors 11 of 19 ● Output frequency accuracy: Test freq

12. alejandro.castaneda.serra@cern.ch 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.

13. alejandro.castaneda.serra@cern.ch 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.

14. alejandro.castaneda.serra@cern.ch 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

15. alejandro.castaneda.serra@cern.ch CIBO (Optical Transceiver) Generators and Detectors 15 of 19

16. alejandro.castaneda.serra@cern.ch CERN, the LHC and Machine Protection 16 of 19 CIBO

17. alejandro.castaneda.serra@cern.ch CERN, the LHC and Machine Protection 17 of 19 CIBO – Block diagram TTL -36 to -39 dBm Sensitivity No EffectMaintenanceFalse DumpBlind Failure 1.96833 x 10 -7 08.29872 x 10 -7 3.428 x 10 -9 CIBO P(Fail) per Hour -15 to -25 dBm Output 1310 nm Singlemode

18. alejandro.castaneda.serra@cern.ch 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.

19. alejandro.castaneda.serra@cern.ch CERN, the LHC and Machine Protection 19 of 19 FIN