Fast Timing in Cosmic Rays Simon Swordy November

Fast Timing in Cosmic Rays Simon Swordy - November 18 th

Above the atmosphere • mass identification • trigger and charge measurement • calorimeter albedo rejection Ground based • dual focus imaging systems

Mass id science • Be 9/Be 10 - age of cosmic rays should show time dilation effects which map out the density of material traveled versus time. Need lorentz factors above ~2. • He 3/4 - material traveled as a function of lorentz factor -> required to find source energy spectra of He • antiprotons - what do these do at high energy? • anti-deuterium - is there any of this?

~3 m

What is the maximum detectable for a TOF system with resolution t and a separation of 3 m? t(ps) max 7. 1 • probably interesting for Be 9/10 and antideuterium 30 12. 9 • not much good for He 3/4 (need 100 or so) 10 22. 4 • works in a region where there are no good cherenkov radiators (n>1. 01 n<1. 1) 3 40. 3 100

Calorimeter albedo problem CREAM-2004

albedo time ~several ns pixel detectors would be much better than paddles because of transit time in paddles

Dual focal length cerenkov imaging - Tr. ICE (Track Imaging Cherenkov Experiment) U. Chicago - ANL Fresnel lens 1 m focal 1 m 3 m Primary, spherical 1 m dia, 4 m focal Detector, 26 x 26 cm 1600 pixels ~ 18 ns delay between images

Size of Direct Cherenkov spot -> nucleus Z • Dual focal length system • 1 st image wide angle includes shower-trigger • 2 nd image higher resolution finds direct Cherenkov component -> ns resolution would be useful here

HOW MUCH? For a NASA experiment on balloons 1 detector plane of 1 mx 1 m could be up to $250 k -> $25 per cm 2 For an imaging cherenkov camera 0. 6 m x 0. 6 m could be $300 k -> $80 per cm 2 Probably needs to get below $100 per cm 2 to be a contender. .