1. CTA-LST Large Size Telescope M. Teshima for the CTA Consortium Institute for Cosmic Ray Research, University of Tokyo Max-Planck-Institute for Physics

2. Large Size Telescope (LST) in CTA MST 10-12m LST 23m SST 4-6m North: Canaries / Mexico South: Namibia / Chile / Argentina LST 23m MST 10-12m SST 4-6m Two stations for all sky observatory

3. Science case of LST LST is optimized in the energy range between 20 - 200 GeV LST is optimized in the energy range between 20 - 200 GeV Low energy threshold Low energy threshold Trigger threshold: 15-20 GeV Trigger threshold: 15-20 GeV Analysis threshold: 20-30 GeV Analysis threshold: 20-30 GeV key physics cases: key physics cases: High-redshift AGNs and GRBs High-redshift AGNs and GRBs Binaries, Pulsars and other type of transients at low energy Binaries, Pulsars and other type of transients at low energy High redshift AGNs (z<3) GRBs (z<10) Pulsars Binaries and transients

4. Specifications/Requirements of LST Diameter: 23m Diameter: 23m Dish area: 400 m 2 Dish area: 400 m 2 F/D = 1.2, F=28m F/D = 1.2, F=28m Dish profile: Parabolic Dish profile: Parabolic FOV = 4.5 degrees, Pixel size = 0.1 degrees (~2500ch camera) FOV = 4.5 degrees, Pixel size = 0.1 degrees (~2500ch camera) Fast rotation: <180 deg/20 sec Fast rotation: <180 deg/20 sec Dish profile: parabolic  isochronicity: <0.6 ns RMS Dish profile: parabolic  isochronicity: <0.6 ns RMS Camera sagging: < 1-2 pixels Camera sagging: < 1-2 pixels Camera oscillation in wind gust: <8mm Camera oscillation in wind gust: <8mm  Active oscillation damping by LAPP IN2P3 Designed by MPI Munich

5. LST 23m size mirror reflector 198 Hex-shape segmented mirrors of 1.5m size 198 Hex-shape segmented mirrors of 1.5m size Total area 〜 400m 2 Total area 〜 400m 2 Central hole for the calibration Central hole for the calibration Permanent AMC (Active Mirror Control) Permanent AMC (Active Mirror Control) 1.5 m Hex Mirror prototype by CTA-Japan Wavelength (nm) Reflectivity (%) SiO2, HfO2 multi-coating

6. Optical axis and permanent AMC Define optical axis with the IR Laser beams Define optical axis with the IR Laser beams High precision inclinometer (a few arcsec)  zenith angle High precision inclinometer (a few arcsec)  zenith angle HR CCD camera at the center of dish to monitor the optical axis and star field  pointing direction in sky HR CCD camera at the center of dish to monitor the optical axis and star field  pointing direction in sky (Camera LED position) – (Optical axis Laser position)  camera sag (Camera LED position) – (Optical axis Laser position)  camera sag (Mirror Laser positions) – (Optical axis Laser position)  misalignments of mirror directions (Mirror Laser positions) – (Optical axis Laser position)  misalignments of mirror directions Target LED OA-Lazer MIR-Lazers SKY MIR-Lazers Stars IMAGE with HR CCD Camera PMT - CAMERA

7. Demonstration of Active Oscillation Damping System for the LST Arch by LAPP IN2P3

8. Gamma/Hadron Separation below 100GeV Scaled width (below 50GeV) 50GeV gamma ray images with LSTs Height of Shower Maximum gamma Hadron

9. Optimization of Telescope geometry Ø 1° source

10. Camera, clusters and Cooling Sealed Camera (MAGIC-II camera) Size: 2.5 m Weight: 2 tons # of Ch: ~ 2500 ch Heat: ~ 5000W Cluster Prototype by CTA-Japan (R.Orito: #1091) 7PMTs CW HV system Pre-Amplifier DRS-4 readout system (4μsec) G-bit ethernet Water cooling System

11. Differential Sensitivity of 4 x LSTs Below 200GeV LSTs will have a good sensitivity Configuration E LST x 4, MST x 23, SST 32

13. CTA Monte Carlo: Expected Light curve for GRB at z=4.3 CTA performance study by S.Inoue, Y.Inoue, T.Yamamoto, et al

14. Summary CTA-LST will provide a fairly good sensitivity between 20GeV and 200GeV CTA-LST will provide a fairly good sensitivity between 20GeV and 200GeV CTA Science will be expanded to the new domain CTA Science will be expanded to the new domain High redshift AGNs (z<3), GRBs(z<10), Pulsars, Galactic Transients High redshift AGNs (z<3), GRBs(z<10), Pulsars, Galactic Transients CTA-LST baseline design CTA-LST baseline design Diameter 23m, Focal length 28m, F/D = 1.2 Diameter 23m, Focal length 28m, F/D = 1.2 FOV 4.5 degrees, Pixel size 0.1 degrees FOV 4.5 degrees, Pixel size 0.1 degrees Many new proven technologies will be implemented Many new proven technologies will be implemented Space frame structure with CFRP Space frame structure with CFRP Total weight ~ 50 tons  180 degrees/20sec Total weight ~ 50 tons  180 degrees/20sec Permanent active mirror control Permanent active mirror control Permanent camera oscillation damping system Permanent camera oscillation damping system Sealed camera with water cooling system Sealed camera with water cooling system 1GHz sampling DRS4 system with 4μsec deep memory 1GHz sampling DRS4 system with 4μsec deep memory

15. Optical axis and permanent AMC Define optical axis with the IR Laser beams Define optical axis with the IR Laser beams High precision inclinometer (a few arcsec)  zenith angle High precision inclinometer (a few arcsec)  zenith angle HR CCD camera at the center of dish to monitor the optical axis and star field  pointing direction in sky HR CCD camera at the center of dish to monitor the optical axis and star field  pointing direction in sky (Camera LED position) – (Optical axis Laser position)  camera sag (Camera LED position) – (Optical axis Laser position)  camera sag (Mirror Laser positions) – (Optical axis Laser position)  misalignments of mirror directions (Mirror Laser positions) – (Optical axis Laser position)  misalignments of mirror directions