1. NuTel Video Conference 6/13/2003 M.A. Huang
Event Rate Estimation
NuTel Video Conference
6/13/2003
M.A. Huang
6/13/2003

2. Monte Carlo simulation
Uniform and isotopic distribution of neutrino trajectory.
Interaction of mountain/sea/atmosphere
Cross-section
Inelasticity
Tau energy loss and decay
Tau decay and initiate shower
Shower simulation
Detector simulation
6/13/2003

3. Progress report Individual event simulation is not finish yet!
No shower and photon information.
No exact trigger condition.
Preliminary estimation of event rate by
Trigger simulation  photo-electron density
Shower simulation  maximum detectable distance
MC simulation  triggered events  acceptance
Tau flux  Event rate
6/13/2003

4. Monte-Carlo simulation
Ntot =106 Neutrino trajectories are simulated
Uniform distribution in impact points
Isotropic distribution in arrival directions Rp V D
Detector - Neutrino plane Rp V
Detector
Rp : impact parameter
D : distance to impact point
6/13/2003

5. Uniform Distribution Uniform distribution in impact points
number density  = Ntot / total volume
dN/dR = 4R2
Rp=Rmax* P1/3 ; P: random probability
cos: -1 to +1
: -180 º to +180º
6/13/2003

6. Isotropic Vz Rp V Vy Vx Detector
Select random vector on plane perpendicular to Rp vector, then rotate it back to detector coordinate. Rp V
Detector Vy Vx
6/13/2003

7. Simulated Acceptance Generated acceptance AMC = 2 3 R 2
For R = 5 km, AMC  1550 km2 sr r
Detector R  
6/13/2003

8. Trigger conditions
1015 eV electron showers, injected from 20, 30, 40 km from detector plan.
Two types of Trigger
50 /m2
200 /m2
Details see S.C. Hsu’s talk D
200 /m2
50 /m2 Rp
6/13/2003

9. Range of impact parameter
Event can be triggered if Rp-D inside phase space of trigger region shown above.
D must be greater than 5 km, to allow shower development Rp V D
Detector - Neutrino plane
6/13/2003

10. Field of View Loa (8º32º) : :90º - 98º ; : 114º -146º
Peak of Loa and Kea
disappear! Too far!
Loa (8º32º) : :90º - 98º ; : 114º -146º
Kea (8º32º) : :91º - 99º ; : 54º - 86º
Loa + Kea (12º100º) : :89º - 101º ; : 50º - 150º
6/13/2003

11. Triggered events
Earth skimming events dominate, most events coming from bottom of valley.
6/13/2003

12. Acceptance Ntr: # of events pass trigger conditions
Atr: Triggered acceptance
Ntot: # of events in simulation = 106
AMC: Simulate acceptance = 1550 km2 sr
6/13/2003

13. Acceptance
Trigger at 50 /m2
6/13/2003

14. Acceptance
Trigger at 200 /m2
6/13/2003

15. Tau flux Tau flux at 1-30 PeV ~ 2-51034 (cm2 sr s eV)1
1 to 30 PeV
Tau flux at 1-30 PeV ~ 2-51034 (cm2 sr s eV)1
Consistent fluxes from calculations of La Babara and G.L. Lin.
Integrated flux from 1 to 30 PeV,  ~ 30. (km2 sr yr) 1
45.7 (km2 sr yr) 1 if use peak value 5 1034 (cm2 sr s eV)1
6/13/2003

16. Event Rate Event rate R = A0.1 Assume 10% duty time
Number of trigger event per year
6/13/2003

17. Discussion Based on 1015 eV shower, E 2.51015 eV
Expect higher acceptance at higher energy,
Event rate could be higher than estimated value.
Average distance to impact point ~ 10 km,
Best site should have valley width  25 Km
For AGN-, NuTel could detect several events per year at E=1-30 PeV.
6/13/2003