1. 1M. Ellis - MICE Tracker PC - 1st October 2007 Station QA Analysis (G4MICE)  Looking at the same data as Hideyuki, but using G4MICE.  Have not yet had time to modify the code that reads the input file to extract the information about the stage position, so have not looked at the most recent file that James produced.  This talk looks only at Runs 7 and 8, taken with a Sr90 source at a fixed location near the centre of the station.  Calibration file used is that determine by LED characterisation of the prototype cryostat/cassette 105 at Fermilab.  Decoding file is that produced by Hideyuki in the “Osaka” format.  Still need to understand differences between this and the files created by Aron. (not crucial for QA, but will be an issue for the cosmic ray test or if we decide to start swapping waveguides around...)

2. 2M. Ellis - MICE Tracker PC - 1st October 2007 Triggers vs Good Events  A trigger is not necessarily a useful event for QA.  Some fraction of self-triggers occur in such a way that the two boards are actually self-triggering off different particles and as such have different times.  These events are rejected.  These un-synchronised readouts occur at a rate which increases exponentially with the readout rate.  As a result, there is nothing to gain by going to a higher readout rate for the tracker QA, as the number of good events per second (i.e. once you remove the badly timed events) actually drops as the readout rate increases.  James has determined the optimum rate and identified the discriminator threshold that results in this rate.  Requiring a triplet (i.e. a hit in each of the 3 views) drastically reduces this and will not be possible for the tracker QA.

3. 3M. Ellis - MICE Tracker PC - 1st October 2007 Some Numbers:  Run 7 u DAQ Rate: 43 Hz u TRIP Threshold: 160 u Events: 10,000 u Events with good readout, etc: 5550 (55.5%) u Events with good readout and a triplet: 258 (2.6%!)  Run 8 u DAQ Rate: 38 Hz u TRIP Threshold: 100 u Events: 10,000 u Events with good readout, etc: 7503 (75.0%) u Events with good readout and a triplet:396 (4.0%!)

4. 4M. Ellis - MICE Tracker PC - 1st October 2007 Run 7 – Space Points

5. 5M. Ellis - MICE Tracker PC - 1st October 2007 Run 8 – Space Points

6. 6M. Ellis - MICE Tracker PC - 1st October 2007 Highest Hit Fibre  Ignore overflows (i.e. ADC value of 255).  Look at cluster in each view that has the highest light yield.  Distributions of the fibre number of the fibre with the highest light in the cluster per plane and the light yield in the cluster with the most light.

7. 7M. Ellis - MICE Tracker PC - 1st October 2007 Run 8 – Plane V

8. 8M. Ellis - MICE Tracker PC - 1st October 2007 Run 8 – Plane X

9. 9M. Ellis - MICE Tracker PC - 1st October 2007 Run 8 – Plane W

10. 10M. Ellis - MICE Tracker PC - 1st October 2007 Triplets  There are events with good triplets, however the rate is very low.  In general, the number of hits seems to decrease with increasing depth into the station, and so requiring the source to produce a hit in all 3 layers is causing a very low efficiency.  As already seen, almost all of the triplets are where we expect to see them (i.e. where the source was).  This is also seen by a spike in the distribution of the fibre number for the clusters that are in a triplet.  Some event displays of a couple of events with triplets follow.

11. 11M. Ellis - MICE Tracker PC - 1st October 2007 Run 8 – Fibre in Triplet, Plane V

12. 12M. Ellis - MICE Tracker PC - 1st October 2007 Run 8 – Fibre in Triplet, Plane X

13. 13M. Ellis - MICE Tracker PC - 1st October 2007 Run 8 – Fibre in Triplet, Plane W

14. 14M. Ellis - MICE Tracker PC - 1st October 2007

15. 15M. Ellis - MICE Tracker PC - 1st October 2007

16. 16M. Ellis - MICE Tracker PC - 1st October 2007

17. 17M. Ellis - MICE Tracker PC - 1st October 2007

18. 18M. Ellis - MICE Tracker PC - 1st October 2007 Proposed Technique  As we can’t use triplets, I propose that we attempt to look at the distribution of PE by selecting the fibres that we expect to see signal from the source on (knowing the source location).  This distribution will likely suffer from an excess of pedestal events (as well as overlay of a lower rate from cosmics) but is the only plausible option in the time frame available.  If we can get this to work with the Sr90 it may be worthwhile also checking with the Co57 source as we have given up the requirement for a triplet.  What follows is a first, very quick, attempt on my part to produce the three plots for a single position of the source.  When I get a chance, I’ll update G4MICE to read the source position and automate the analysis slightly.

19. 19M. Ellis - MICE Tracker PC - 1st October 2007 All Events: Plane V – Fibre 107

20. 20M. Ellis - MICE Tracker PC - 1st October 2007 All Events: Plane X – Fibre 98

21. 21M. Ellis - MICE Tracker PC - 1st October 2007 All Events: Plane W – Fibre 113

22. 22M. Ellis - MICE Tracker PC - 1st October 2007 Conclusions  Triplet Analysis is not an option.  Co57 source is not ruled out and we should take some data to compare with the Sr90 (perhaps this afternoon or tomorrow?)  LY distributions for fibre that is predicted by stage position may be a solution, but the first plots do not look perfect.  If this technique can be made to work, then we can take data at a rate of about 25 Hz (i.e. 25 usable triggers per second).  We have 4 weeks until November, so: u 4 x 5 x 8 = 160 hours u 160 x 3600 = 0.576 million seconds u 14.4 million events.  Divided by 15 stations that means we can probably take close to 1 million events per station.  How do we want to divide that up?  N.B. The numbers above are usable events, not the total number of triggers we will set the DAQ to record! That number will be higher.