1. Off-line Event Building
Hidetada Baba
RIKEN, Japan

2. Small DAQ Take all detector data by 1 DAQ system Detector A DAQ System
Detector B
Take all detector data
by 1 DAQ system
Coincidence Trigger
by Hardware

3. Dead time of a DAQ system
Trigger
Dead Time
R Trigger Rate
t Dead time
Nacc N of Accepted Trigger
Ngen N of Generated Trigger

4. Parallel DAQ Common trigger Parallel Readout Event build
Detector A
On-line
Event Builder
DAQ B
Detector B
Coincidence
Trigger
Common trigger
Parallel Readout
Event build
based on the “Event Number”

5. Common trigger, individual dead time
DAQ A
Dead time
DAQ B

6. Common Trigger + Individual dead time
The best is:
tB =0, tA = tB
tB = 200us
Combined
live time
Common trigger case,
we should use
the “Common dead time” mode

7. Go to “Individual Trigger”
DAQ A
Detector A
Coincident
Data
DAQ B
Detector B
Detector C
DAQ C
Individual
Trigger
for Each DAQ
Software Trigger
We can change the trigger condition,
after the experiment

8. Go to “Individual Trigger”
DAQ A
Detector A
DAQ B
Detector B
Coincident
Data
Detector C
DAQ C
Individual
Trigger
for Each DAQ
Distribute Clock
= Time Stamp
48bits, 100MHz(10ns)

9. Relative timing spectra to find “Coincidence”
Beam
Silicon
Germanium
TSSi-TSBeam
Isomer
Gamma
Coincidence
Window by
Software
TSGe-TSBeam
Offset Width

10. To know combined dead time
DAQ A
Dead time
of each DAQ
DAQ B
DAQ C

11. To know combined dead time (live time)
DAQ A
DAQ B
DAQ C
Trigger Recorder
(Dead time free)
Store TS of all triggers

12. Beta decay experiment with RI beam @ RIKEN
Beam line Detector
for particle identification
Silicon Detector
for Beam and Beta
Germanium Detector
for Gamma ray

13. Beta decay experiment with RI beam @ RIKEN
Beam line Detector
for particle identification
Silicon Detector
for Beam and Beta
Prompt Gamma
order of ps
Isomer Gamma
order of us
Germanium Detector
for Gamma ray ZA

14. Beta decay experiment with RI beam @ RIKEN
Beam line Detector
for particle identification
Silicon Detector
for Beam and Beta
Germanium Detector
for Gamma ray

15. Beta decay experiment with RI beam @ RIKEN
Beta ray
order of ms
Isomer
Gamma
Beta delayed
Gamma ZA
Z+1A

16. Beta decay experiment with RI beam @ RIKENZA
Z+2A
Z+1A

17. Beta decay experiment with RI beam @ RIKEN
A variety of physics events
Long time scale range
Difficult to decide “Coincidence Trigger” during experiment
Separately measure “Beam”, “Silicon”, “Germanium” data = Individual Trigger
Use “Time Stamp”, “Software Trigger”

18. Developing a new “Off-line event building” system
Based on Database technology
RIKEN - Saclay - GANIL
Easy to use
Fast event building
Generic data format (e.g. ROOT, ASCII)
Multi DAQ system
Different DAQ systems will come to RIKEN
RIKEN DAQ, EURO-Ge (GSI), SAMURAI Si (HINP/NSCL), MINOS(GET), SAMURAI TPC(STAR/GET), GRETINA?(USA)

19. Now developing (RIKEN - Saclay - GANIL)
Return
combined data A + B
Off-line
Event Builder
Client
Req
DAQ A
Put request
Data
+ TS A
Request
= “Detector A AND Detector B”,
2012 May 3. 19:00-21:00,
window = ns”
DAQ B
Data
+ TS B DB
List of
Events
DAQ C
Data
+ TS
A catalog of Events
Contain all TS values

20. Now developing (RIKEN - Saclay - GANIL)
An event record
Time Stamp
Detector ID
Location of this data
Tag
Raw Data
DataBase
Resister
all event records

21. Example, Particle IdentificationZ
A/Q
Raw data
TOF
Position dE
Target

22. Register Raw Data Storage DataBase Event N TimeStamp TOF Position dE 1
120
102
-20, 2
140 2
1203 99
12, 3 70 3
2331
8, 1 68 4
4510 98
-6, 10
Storage
DataBase
DAQ A

23. Register Analyzed Data
Event N
TimeStamp
TOF
Position dE 1
120
102
-20, 2
140 2
1203 99
12, 3 70 3
2331
8, 1 68 4
4510 98
-6, 10
Event N
TimeStamp A Z
Tag 1
120
108 40
108Zr 2
1203
100 36
100Kr 3
2331 98
98Kr 4
4510
104 38
104Sr
DataBase

24. Event selection by Database Query Command
SELECT * from Table_A, Table_B
WHERE TS_A - TS_B BETWEEN -100 AND 100
No good Query
TS_A
120
1323
2342
4523
6621
TS_B
140
2403
2842
8023
9111
DB try to do
“TS_A - TS_B”
Too many calculations

25. Event selection by Database Query Command
SELECT * from Table_A, Table_B
WHERE (TS_A > TS_B-100) AND (TS_A < TS_B+100)
Good Query
TS_A
120
1323
2342
4523
6621
TS_B
140
2403
2842
8023
9111 20
DB can use
efficient search
(e.g. Index scan)
220
The result is the same, however quite faster

26. Beta decay exp. 2012@RIKEN On your laptop RIKEN side DB Pre Analysis
RIKEN format
Munich
format
GSI
format
Pre Analysis
ROOT
ASCII
Beam Si Ge
108Zr TS A Z
Tag TS
E(MeV)
T(ns)
Pos TS
E(MeV)
T(ns)
Pos
Put requests
via Web-Browser
Down load
combined data
Off-line
Event Builder DB

27. Summary Individual trigger system Dead time
Synchronized by Time Stamp
Dead time
Determined by collecting all trigger timings
New Off-line event building system
Software trigger after data-storage
Easy to combine different DAQ systems
Output file = Generic data format
Data base for the event selection
Useful query commands, Scalable, Robust, Fast