1. ETD/Online Report D. Breton, U. Marconi, S. Luitz
WS goals session – Elba Meeting
May 31th 2010
ETD/Online - SuperB Elba Workshop - May 2010

2. Technical choices for the TDR : front-end
There is a certain amount of common questions for the different front-end electronics:
Radiation
We need a radiation map in order to fix the rules for the electronics mitigation
We have to be sure that the technologies chosen can handle radiation
We have to define rules for selecting the commercial components
Power supplies
Do we intend to use radiation-tolerant supplies on the detector (short cables but more expensive supplies) or remote standard supplies (cheaper supplies but long cables) ?
Do we want a common supply policy at the detector level ?
Grounding and shielding
We have to define the rules
Our preference is a strong common ground
Electronics integration on the detector
When designing the system, it is important to think of:
How easy it will be to change a board (access, connectors, …)
Ensuring there will be no extra pressure on the connectors (for instance avoiding using connectors to mechanically hold boards
ETD/Online - SuperB Elba Workshop - May 2010

3. Technical choices for the TDR : trigger
Baseline:
re-implement BaBar L1 trigger with some improvements
Shorter latency (~4us instead of 12us)
Higher sampling frequencies (DCH and EMC)
2-d map for calorimeter
Possible additions
SVT trigger
Bhabha Veto
Challenge
To keep the event loss due to dead time below 1% => a maximum of ~70ns “per-event dead time” is allowed in trigger and FCTS
Other considerations
What goes in L1, what in L3, what’s the optimum?
See trigger session (ETD 2)
First meeting of “Trigger Interest Group”
150kHz
Exponential Inter-arrival time pdf.
ETD/Online - SuperB Elba Workshop - May 2010

4. Technical choices for the TDR : common items (1)
FCTS
Well on tracks. No major open question. Will most probably be a custom crate (see talk on Wednesday)
Links
Clock distribution has to be perfectly safe
The solution chosen will have to guaranty that clock will always be present despite radiation events
Control link
We have to validate the commercial chipset for radiation: but it has to be the one we will buy! (actually true for all components)
We have to define the command frame length and the reasonable overhead necessary for redundancy
We have to define the format of the trigger primitives sent back from the FEE
Readout link
We have to validate the commercial chipset for radiation
We have to refine the link effective payload in order to allow the subsystems to finely tune their number of links
ETD/Online - SuperB Elba Workshop - May 2010

5. Technical choices for the TDR : common items (2)
Common FEE
We have to define the depth of the derandomizer buffers, located between the latency buffers and the readout links
ECS
Well on tracks. We take benefit there of the ongoing developments for LHCb.
ROM
A new R&D has been launched, implying:
Building and testing an optical to PCIe interface board to get readout data
Writing the Linux drivers for PCIe
Evaluating the optimal number of input and output boards which can be hosted in a single mother board
Testing the transmission rate/bandwidth achievable by using standard/commercial 10 GbE.
ETD/Online - SuperB Elba Workshop - May 2010

6. Technical choices for the TDR : Online
Well under control
Event Management and Event Builder
Define interaction between FCTS, Event Builder and HLT
What information needs to be broadcast to the ROMs, what to the FEE to ensure consistent event build – has implications for FCTS/ROM design
All other components of the Online system are expected to be commodity / off-the-shelf
Only notional technical choices will be required for the TDR to get to a reasonably accurate estimate of cost and manpower, such as:
HLT farm architecture (storage, network)
Detector Control System
Computing infrastructure for the Online system
Data quality monitoring
ETD/Online - SuperB Elba Workshop - May 2010