2. MICE AFEIIt Timing and Triggering
Consulting with Kwame Bowie at Fermilab who defined the requirements and specification in December 2006.
Spill Reset:- Align state machines in advance of Spill
Clock:- Derived from and phase aligned to ISIS RF to allow PLL/VCO to achieve 55MHz clock
Live XING:- Trigger 100ns charge integration windows
L1A:- Level 1 Accept. TOF triggered requests readout from pipeline for digitization

3. Original System Block Diagram
Min Skew ensures all boards sample at same instant
Now Spill Reset and Live XING
All Signals
10nS Max Skew TTL onto board
Delay to board 275nS→25uS

4. Timing Waveforms

5. ISIS RF(x2) – Bunch Repetition
Extract/Target
Accelerate
Inject
1mS spill – target in beam
PLL Start lock

6. ISIS RF details - Ian Gardner
Space for TTL conversion module
Master pulse generator

7. ISIS control cable area
Feed through from diagnostics
Spare cables for use

8. Typical signal from R7HM1
Monitor to Diags room ~560nS delay

9. tL1A: End to End subsystem delay
L1A Trigger Waveforms
tTOF DEL: Fixed delay due to cable and electronics from TOF to trigger O/P
tpropagation: Fixed delay from particle’s travel between TOF and signal at AFEIIt
tpipeline: AFEIIt parameter setting pipeline depth. (max 48clock cycles)
tL1A: End to End subsystem delay
tprogrammable:
tL1A - tTOF DEL - tCABLE

10. Functional Block Diagram
2 signals MICE, 2 ISIS
Translation module/Fan-Out
Fine delay can move
Start of Spill flexible
Delay module stand-alone
Provided by ISIS diagnostics
4 boards per Cryostat
4 Cryostats = 16 AFEIIt

11. Purchased modules 5 x Caen V976 VME Fan-Out
(2 x 1:8 per module, NIM-TTL translation)
2 x Caen V972 VME Fine Delay
(0-31.5nS, calibrated co-ax stubs)
2 x Highland Technology T560
Stand alone programmable delay module
RS232 or Ethernet, 750ps rise, 10ps res

12. Hall Layout - Tracker Cryostat systems Signal sources Cable routing
Tracker racks
Trench
Grounding

19. Grounding Diagnostics grounded racks, under floor busbar
Ground plate in hall - split (trackers/RF cav), cryo chassis feet sit on, PSU in racks connected
Cryo introduce line noise & compressors???
5mV ground differential! (Ian Gardner)
IG said not seen big issues before with EMC noise in Coax

20. AFEIIt timing&triggering actions
Burst Gate & ISIS RF “Clock”?
Decide cable routing
Cable purchase & laying
Testing modules & signal simulation (Now)
Grounding scheme?
Crates?

21. (Some) Propagation delays
50M+ from Rf generation to Synchrotron (~250nS)
Time for bunch from target to Tracker 1 & 2 (~100ns + 30nS)
From Trackers through fibres to VLPC and charge to AFEIIt
15M+ from diagnostics room to rack 2 (75nS)
25nS on delay generator (L1A)
2.6nS on fine delay (clock)
9ns fan-out
16M to tracker 1 (80nS)
Fan-out cables