1. T. Burnett: IRF status 5-feb-061 DC2 IRF Status Meeting agenda, references at: http://confluence.slac.stanford.edu/display/DC2/060203 http://confluence.slac.stanford.edu/display/DC2/060203 Deadlines Feb 10: finish parameterization definitions (functional forms, bins) Feb 13: finish implementation Feb 17: Verification Feb 20: Final report Event Classes - finalized to be A and B as proposed by Julie DC2Cuts.C now in DataChallenge package, under cvs control. Effective area - Jean Dispersion – Riccardo PSF – Toby (new stuff)

2. T. Burnett: IRF status 5-feb-062 The calibration data – updated with new low energy Photon response from “allgamma” Version v7r3p4, with reprocess to update CTB variables (4000-2)*50 K generated events into 6 m 2 : uniformly in log(E) from 18 MeV to 180 GeV (4 decades) uniform in cos(  ) from -1 to 0 (upper LAT hemisphere) (2000-1)*5 K generated 1.25 <log(E) < 3.75. (1.5 decades) Factor of 40/3 more for E<562 MeV Background Version v7r3p5, also CTB updated, and filtered with CTBGAM>0 18675 seconds of live time, distributed uniformly over 3 days of the DC2 orbit new

3. T. Burnett: IRF status 5-feb-063 PSF - Jean class A class B front back

4. T. Burnett: IRF status 5-feb-064 Dispersion - Riccardo

5. T. Burnett: IRF status 5-feb-065 Dispersion – better function

6. T. Burnett: IRF status 5-feb-066 Dispersion, cont Parameterization of energy and angle in progress – needs more data at low energy, has not use the new run Class B – big problem!

7. T. Burnett: IRF status 5-feb-067 Class B: what to do with it Substantial low energy tail in dispersion These events will not be fit properly! Is it worth it?  I think not! But if we include them, we have to treat the analysis properly: the effective area for analyses that depend on the energy must be reduced good energy ?

8. T. Burnett: IRF status 5-feb-068 PSF (Toby) Revise scaling function so that 68% containment is ~1 for class A.

9. T. Burnett: IRF status 5-feb-069 PSF, cont Since the fit is restricted to ~10 68% radii, there is a potential normalization issue, if the predicted tail is different from the measured one. The largest class A deviation is at right class A front fits are all within 0.1% overestimate: 0.5% underestimate: 1.6% class A back

10. T. Burnett: IRF status 5-feb-0610 Addendum: new class B Riccardo suggested to modify the class B definition by requiring CTBGoodEnergyProb> 0.3 for all events. Here are the resulting acceptances. The blue points are those for which the measured energy is >60% of the actual.