1. EAS simulated acceptance skymap Olivier Martineau-Huynh 30/04/2014

2. Status 30/04/2014: Fields EVA computation: – ~all done in : [0-90°]+[180-270°] (TREND convention: [270-360°]+[90-180°] ) – 16000 done in [90-180°], 8000 remaining (Junhua, 04/25) – 3000 done in [270-360°], 43000 (?) remaining (Siqi+Jianrong, 04/28) Voltages NEC computation: – Already processed: 2159 core positions, 50603 Efield files in [0-90°]. 1588 core positions, 38925 Efields files in [90-180°]. 963 core positions, 23324 Efields files in [270-360°]. – Core positions linked to shower 8665868 (zen = 54 deg, az = 3 deg): 230 shower 8629961 (zen = 31 deg, az = 81 deg): 91 are discarded. Trigger Matlab computation – 192 showers analyzed (154 with valid data &  <80°) in [0-90°] & [180-270°] No offline cuts (TREND-50 analysis) applied yet.

3. Skyplot of fully processed showers (192 showers, 154 below 80°) North East Skyplot of full EAS simu data set @ 10 17.5 eV (402 showers)

4. Matlab process For given geometry (  x core ): – check if antennas signals are above threshold (8x  noise ) – If OK for 5+ antennas, tag this geometry as ‘triggered’. For each direction, compute ratio N triggered /N simulated (N simulated = 20 in principle) Simu voltage x calib + noise

5. Acceptance skymap Plot 154 simulated showers weigthed by ratio N triggered /N simulated + smoothed by experimental resolution. Map normalized to 1. EW polarNS polar Stats certainly still too low to produce smooth map.

6. Acceptance skymap Fluctuations dominated by shower direction non uniform distribution. Shower direction smoothed by experimental resolution

7. Acceptance skymap Normalized by smoothed direction map erases shower directions fluctuations effect. Clear differences between NS & EW polar along NS axis (as expected). EW polar NS polar

8. EW polar NS polar Az and Zen distribs

9. EW polar simulated data to be compared to… experimental data Reminder: map of geomagn effect intensity for EW polar (analytical model). Our 396 EAS candidates for EW polar PRELIMINARY! EAS selection cuts to be refined thanks to simulated data.

10. Data/Simu comparison Data Simu EW polar Data (smoothed)

11. Data/Simu comparison Match could be worse, but clear differences at Low zenith angles (dead antennas & lower experimental E?) Large zenith angle (bad simulation of ground effects?) West direction (  ~270°)… Could be an effect of our data analysis cut (EAS candidates rejected if other event in same direction within +- 3minutes) South direction (  ~180°)… Geosynchrotron effect not as dominant in simulation compared to data (ie: real energy lower)? Simu Data Simu Data

12. 50°<  <80° Simu Data Not so similar… « Dead antennas » certainly play a role but again lower experimental energy could provide an explaination. Antenna multiplicity

13. Preliminary conclusions No obvious flow/issues in the simulation process, results look encouraging! TBD: – Complete the 10 17.5 eV simulated skymap asap. – Produce map @ 10 17 eV (  <70° + half sky (?) ) In parrallel: – Define EAS selection cuts and wrap up data analysis