Electron Beam as a standard candle for EHECR air shower Feb.26th, 2004 Kashiwa Masaki Fukushima / ICRR

Efficiency of Air Fluorescence Total Absorption Calorimetry by AF ：　 Meas. of Absolute Energy 2. Atmospheric Correction 1. Scintillation Efficiency Loss in the transmission DE > # of photons 3. Telescope Parameters Mirror Window Filter PMT QE+CE Electronics Gains Efficiency of Air Fluorescence # of photons > ADC ch. Biggest Headache：　No Calibration Source to Determine Absolute Energy Scale

LE Electron Beam as Air Fluorescence Calib. Source Bulk of air shower E loss by LE electrons / γ’s 40 MeV electron x 109 particles ~ 4 x 1016 eV Critical energy ~ 95 MeV After 30 m air, ΔE~7 MeV, mult.scatt. ~ 100 mrad Cherenkov threshold ~ 25 MeV Shoot electron beam up in the sky 100 m away from the station. ( equiv. to 4 x 1020 eV shower 10 km away)

・ Distortion of focus and Horizontal Position Scan about < 50m Problems? ・　Distortion of focus and 　　acceptance. ・　CAMERA dead zones. 　　> angular steering > horizontal scan ・　Cherenkov light? >>>　precise MC possible for 40 MeV photons by GEANT/EGS 100m away LINAC BEAM 67m high Small Anglular Steering LINAC BEAM 100m away

GEANT Simulation by Sakurai. 20 MeV 40 MeV 100 m away Telescope FoV FoV of 1 PMT ~100k pe / PMT From Energy Loss to ADC ch. AF Source of Known Total Energy. End-to-End Calib.

Requirements for the Accelerator 　Energy：　１０－４０　MeV, variable 　Intensity：　１０ ９ electrons　/　pulse, variable 　Pulse Width：　１－１０　μs 　Repetition：　～ １ Hz 　Beam Size：　～１０ ｍｍ φ 　Beam Spread：　～１ mrad 　Accuracy of Energy x # of particles：　～１％ 　small, stable and low power　（desert spec.） 　portable

Microtron idea ・ compact injector for SR ・ high energy possible 6 MeV linac ・ compact injector for SR ・ high energy possible ・ accurate energy ・ energy stepping

Linac idea ・ medical linacs with 20 MeV or less C band acc. structure S band acc. structure Klystron Pulsed Power Supply ・ medical linacs with 20 MeV or less ・ 5 GHz system for LC study at KEK (40 MeV/m reached) ・ magnetic energy analyzer required ・ very compact but magnet + Klystron is heavy

Measuring together with Laser Candle for atmosph. transparency monitoring Rayleigh scatt. Known x-section ETOT / hν = # of photons 10 mJ ~ 1016photons １００ｍ １０ ｋｍ

Working with Laser Candle Reach of Lidar （< 20 km） Laser Candle Linac Candle

Summary: Electron Beam as AF Calibration Source Absolutely calibrated AF source The idea survived initial inspections Working examples; FLASH and Super-K Linac calib. Standard beam technologies Adaptation to “desert” environment required. Very low dose, but rad. protection must be assured. ~ 2 years and ~ 1M$ for construction Help and expertise at KEK and US acc. Lab.