Back Ground Rejection Status
for
DC2
a la Ins. Miner Analysis
Bill Atwood, SCIPP/UCSC, Oct, 2005
1
GLAST
First Look at glast-ts production
3-Oct-2005
Series 1: 409160 in tuple / 123556 after RF (only FilterStatus _HI == 0 used by TB)
(This series does not have the single tile energy vars)
after Act.Dist&SSDVeto:
82306
after GoodEnergyProb > .1: 81674
Series 2:
408151 in tuple /
123120 after RF
after Act.Dist&SSDVeto:
82440
after GoodEnergyProb > .1: 81795
Series 3:
409098 in tuple /
123110 after RF
after Act.Dist&SSDVeto:
82349
after GoodEnergyProb > .1: 81746
Each series equals .01 days or ~ 864 sec. on orbit with 744 per series live time due to the SAA
– the 3 together represent 2232 sec.
The following is from Toby's e-mail dated 4-Oct-05 5:33 pm
Series incoming triggers
downlink
1
38191926
6100518
409281
2
38053681
6078677
409415
3
38130276
6093686
409221
4
37845955
6054390
406189
total 152221838 24327271
Rates
8177 Hz
Bill Atwood, SCIPP/UCSC, Oct, 2005
Note: that the numbers I see are
a little different in the incoming ntuples –
Toby says this is due to him taking numbers
from the logs rather then the tuples and failed
jobs don't get counted properly.
Total live time = 2976 sec. for the 4 series
1634106
549 Hz
2
GLAST
Vtx Topologies, THICK Radiators, CalEnergyRaw < 350 MeV
(Note I'm trying breaking the lowest energy bin into THICK & THIN radiators at Steve's suggestion)
Prefilter: Exclude AcdUpperTileCount > 0 | AcdLowerTileCount > 1 | AcdRibbonActDist > -1999
where UpperTileCount = Top + 0 + 1 + 2 and LowerTileCount = 3
1000
#AGs as indicated
1547 Bkg. Events
By Varying the # of AGs
used to train the CT, the
relative efficiency of the
selection of Bkg and AGs
changes.
700
500
400
These are for Prob(g) > .50
200
300
100
The nominal rate for
Bkg. in each channel must
be kept to < .03 Hz
By changing the number of AGs - its equivalent (? similiar at least) to weighting the events – except for the
statistical fluctuations.
Bill Atwood, SCIPP/UCSC, Oct, 2005
3
GLAST
300 AGs
All
g
Bkg
249
892
Pr > .5
144
39
Eff
.58
.044
This is what the CT vars.
and probs. look for 3
different mixes of AGs
BestEnergy > 100 MeV
500 AGs
g
Bkg
All
397
892
Pr > .5
258
57
Eff
.65
.064
BestEnergy > 100 MeV
1000 AGs
g
Bkg
All
812
892
Pr > .5
721
150
Eff
.89
.168
Bill Atwood, SCIPP/UCSC,
Oct, 2005
BestEnergy
> 100 MeV
4
GLAST
Try Training CTs using BestEnergy > 100 MeV
g
Bkg
All
200
892
Pr > .5
98
Eff
.49
PreFilter
as before
BestEnergy > 100 MeV
g
Bkg
All
400
892
36
Pr > .5
289
63
.040
Eff
.72
.071
This is marginally worse... so I will inculded
all events to train CTs
The event mix changes with cos(q) as well. We'll probably de-select on events near the edge of the FoV
(e.g. cos(q) < -.3 rather going out to cos(q) < -.2)
No cut case
PreFilter
cos(q) < -.3
as before
Prob. > .5
AG eff = 129/235 = .54
Bkg. eff = 25/792 = .03
CT Variables and
Prob for Vtx, Thick,
< 350 MeV
Bill Atwood, SCIPP/UCSC, Oct, 2005
5
GLAST
VTX, THIN, CalEnergyRaw < 350 MeV, cos(q) < -.3
PreFilter
This is much worse in terms of efficiencies –
THICK
eAG: .87
eBkg: .46
as before
PreFilter
THIN
eAG: .92
eBkg: .84
AcdActiveDist > -199 | AcdRibbonActDist > -1000
THIN
eAG: .73
eBkg: .63
Still its bad - but????
This PreFilter is considerably worse for
the THICK events then the one dev. for
it. THICK and THIN seem to be just
DIFFERENT
THIN
eAG: .67
eBkg: .02
Prob>.5
cos(q) < -.3 && BestEnergy > 100 MeV
Bill Atwood, SCIPP/UCSC, Oct, 2005
6
GLAST
VTX, All Layers, 350 < CalEnergyRaw < 3500, cos(q) < -.3
PreFilter
All Layers
eAG: .97
eBkg: .55
AcdActiveDist > -199 & AcdRibbionActDist > -1990
This g ineff. is consistent
with conversions in blanket
and tiles
All events now have
BestEnergy > 100 and
cos(q) < -.3
Bill Atwood, SCIPP/UCSC, Oct, 2005
7
GLAST
VTX, All Layers, 3500 < CalEnergyRaw, cos(q) < -.3
The Remaining Bkg Event
PreFilter
e- (e- Splash)
Event Well Reconstructed
AcdActiveDist > -10 | CalTrackAngle > .5
| CalTrackDoca > 40
This is NUTS!
The event clearly has to
be pointing at an ACD
Side tile and there
is no SSD Veto.
The Doca Calc. says the
event had a track well
within a tile – so why is
the ActiveDistance set to
its rogue value?
This is a glast-ts generated event.
Can Toby find it?
(It comes from either series 2 or 3)
We NEED a picture of it!
Bill Atwood, SCIPP/UCSC, Oct, 2005
8
GLAST
Vtx Topology Summary (All numbers for BestEnergy > 100 MeV & BestZDir < -.3)
Prob. > .50
PreFilters
Background Rejection
Path (BR.Path) not yet
determined
Level Name
Counts
VTX&CAL_Hi
2541/108
VTX&CAL_Med
5080/1050
VTX&CAL_Low
6273/3175
All Gamma
Loss
.013
.120
.465
(g/Bkg)
Background
Background Source
Breakdown
MIP
Finder
Failure
HeavyIons have gone away
Bill Atwood, SCIPP/UCSC, Oct, 2005
9
GLAST
1Tkr, THICK layers, CalEnergyRaw < 350 MeV
cos(q) < -.3
PreFilter
AcdActiveDist > -199 | AcdRibbonActDist > -1999 |
AcdDoca < 1999 | CalTrackDoca > 200 |
EvtECalTransRms > 2.5 | CalMaxXtalRatio > .8 |
Tkr1FirstChisq > 2.5 | Tkr1ToTTrAve > 2
Desperation: This is the toughest subclass.
In DC1 we had to through all these away. This
is better but clearly not there yet.
Note that ~ 50% of the events are
below BestEnergy < 100 MeV
THIN
eAG: .68
eBkg: .03
Prob>.5
cos(q) < -.3 && BestEnergy > 100 MeV
Bill Atwood, SCIPP/UCSC, Oct, 2005
10
GLAST
1Tkr, THIN layers, CalEnergyRaw < 350 MeV
cos(q) < -.3
PreFilter
Desperation: This is the 2nd toughest subclass.
AcdActiveDist > -199 | AcdRibbonActDist > -1999 |
CalTrackDoca > 200 | EvtECalTransRms < .8
Note that ~ 40% of the events are
below BestEnergy < 100 MeV
THIN
eAG: .72
eBkg: .04
Prob>.5
cos(q) < -.3 && BestEnergy > 100 MeV
Bill Atwood, SCIPP/UCSC, Oct, 2005
11
GLAST
1Tkr, All layers, 350 MeV < CalEnergyRaw < 3500 MeV
cos(q) < -.3
PreFilter
AcdActiveDist > -199 | AcdRibbonActDist > -1900 |
CalTrackDoca > 40 | CalTrackAngle > .5 |
CalXtalRatio > .85
All Layers
eAG: .73
eBkg: .04
Prob>.5
cos(q) < -.3 && BestEnergy > 100 MeV
Bill Atwood, SCIPP/UCSC, Oct, 2005
12
GLAST
1Tkr, All layers, CalEnergyRaw > 3500 MeV
cos(q) < -.3
PreFilter
This PreFilter was not done properly
first time around.
Here's a re-do
CalTrackDoca > 30 | CalTrackAngle > .3
Leaving out all ACD vars. in PreFilter
All Layers
eAG: .98
eBkg: .015
Prob>.5
cos(q) < -.3 && BestEnergy > 100 MeV
Bill Atwood, SCIPP/UCSC, Oct, 2005
13
Note however that the CTs insist on
using the ACD.
GLAST
2nd Time Around
1Tkr Topology Summary (All numbers for BestEnergy > 100 MeV & BestZDir < -.3)
Prob. > .50
PreFilters
Background Rejection
Path (BR.Path) not yet
determined
Level Name
Counts
1Tkr&CAL_Hi
15098/8932
1Tkr&CAL_Med
5944/17242
1Tkr&CAL_Low
4891/33163
All Gamma
Loss
.075
.394
.641
(g/Bkg)
Background
Note how much larger the Bkgs are w.r.t. Vtx
except for CalEnergyRaw > 3500 MeV
Background Source
Breakdown
MIP
Finder
Failure
Bill Atwood, SCIPP/UCSC, Oct, 2005
14
GLAST
v7r2 SLAC 2M All Gamma Run
Pr(GAM) > .50
Number > 1 GeV = 1726 in 28 bins
62/bin x 50 bins = 3100
3100/(2x106 / 100) x 6 m2
<NBIN> * 150 = Aeff (cm2)
or N>1GeV * 5.36 = Aeff(cm2)
Aeff = 9300 cm2
2469/bin
SRD Limit
Number > 1 GeV = 70883 in 28 bins
(2531) x 50 Bins = 113500
113500/2x106 x 37.7 m2-str
<NBIN> * .943x10-3 = Aeff x DW(m2-str)
or N>1GeV *3.37x10-5 =Aeff x DW(m2-str)
Aeff x DW = 2.39m2-str
Background: 319 Events or .16 Hz
(SRD ~ .03 Hz)
Bill Atwood, SCIPP/UCSC, Oct, 2005
15
Fall-off past 10 GeV improved – however
this results from the CTs using AcdActiveDist to kill
the high energy cosmic electron component in the
background – it may be a fact of life for now...
GLAST
Near On-Axis
cos(q) < -.9
These basically meet the SRD
Edge of FoV
Bill Atwood, SCIPP/UCSC, Oct, 2005
cos(q) > -.6
16
GLAST
Direction Anti-Correlated events: 416 Events
Residual Background Dissection
PSF Class
Prob.GAM > .3 (relaxed cut)
1151 Events
These are dominated by upward moving protons. This is
what the MIP Finder was suppose to identify
No Correlation: 560 Events – large component of Limb gs
PSF Class
Direction Correlated events: 175 Events
PSF Class
Location of First
Hit on Found Track
Come in through the corners and there is a definite handedness
this suggest a ERROR IN THE ACD CODE / GEOMETRY
Bill Atwood, SCIPP/UCSC, Oct, 2005
17
GLAST
Event Spectra both MC Truth and as Reconstructed
After PreFilter Stage
No Prob.GAM Cut
61 Events
Rate = .03 Hz
Prob.GAM > .7
(Meets Aeff and Background
rate req.)
62352 events > 1 GeV
Bill Atwood, SCIPP/UCSC, Oct, 2005
Aeff x DW = 2.1 m2-str
18
GLAST