1. Photo-Nuclear Physics Experiments by using an Intense Photon Beam Toshiyuki Shizuma Gamma-ray Nondestructive Detection Research Group Japan Atomic Energy Research Institute

2. Nondestructive Isotope Detection Fingerprint of isotopes W A N T E D Nuclear resonance fluorescence (NRF) R.Hajima, et al., J. Nucl. Sci. Tech. 45, 441 (2008). High energy  rays are used; High penetrability Applicable for identification of materials such as specific nuclear materials, explosives, etc. shielded by heavy metals

3. Laser Compton Scattering  Rays LCS  rays can be generated by scattering of high energy electrons with laser light. Highly monochromatic Highly polarized (linearly/circularly) Energy variable Small divergent Electron Laser light LCS  ray Vertical polarization:  =90° E1: Horizontally scattered M1: Vertically scattered LCS beam E1 M1

4. Physics with LCS Photon Beams Nuclear physics Fundamental collective motions via E1 and M1 excitation Pygmy dipole resonance, spin-flip M1, scissors mode, etc PNC observation with circularly polarized photons Long-standing question in nuclear physics Interference between weak-bosons and nucleons Nuclear astrophysics Nucelosynthesis (  process and process) Inelastic neutrino scattering cross sections Reliable nuclear model, e.g, shell model predicting M1 response K. Langanke et al., PRL 20501 (2004) A. I. Titov and M. Fujiwara, J. Phys. G 32, 1097 (2006)

5. Strength Distribution of Dipole Excitation GDR: Electric giant dipole resonance PDR: Electric pygmy dipole resonance M1: Magnetic spin-flip dipole mode Sc: Magnetic dipole scissors mode (orbital part) p n GDR p n PDR M1 Sc p n p n np EE Strength GDR 0 E th ～ 8MeV ～ 15MeV PDR M1 Sc ( ,n)( ,  ') EnEn NRF

6. NRF Measurements with LCS Photon Beam Clear difference observed between different polarization setups Unambiguous determination of multipole orders (E1/M1) Observation of the detailed level structure below E n in 208 Pb --- Tensor force E1 M1 M1 transitions (MeV) 6.5 7.07.5 Parallel Perpendicular M1 E1 T. Shizuma et al., Phys. Rev. C 78 061303(R) (2008) Obtained by using LCS  rays at AIST, Tsukuba, Japan

7. Measurements above Neutron Emission Energy Neutron time-of-flight (TOF) method Duration between  pulses and neutron signals Neutron Neutron emission n

8. Neutron TOF Spectrum Obtained by using LCS  rays at NewSUBARU Structures are observed Preliminary Time Neutron energy LCS  Neutrons 

9. Polarization Effects K. Horikawa et al., JPS meeting, Sep. 2010 LCS beam Neutron

10. Summary The information on the states above the neutron emission energy can be optained through the neutron TOF measurement. - Dipole strength distribution, parity, excitation energy etc. Small  E/E (10 -6 ～ 10 -4 ): Selective excitation of levels Short pulse duration: High resolution measurements High intensity : Increased flight distance →High resolution measurements Rare isotope measurements Less amount of target materials

11. TOF Energy Resolution Assuming detector time resolution = 1 ns and distance = 3m

12. Estimation I s =1.2x10 -22 cm 2 eV for E  =10 MeV and  0 =1eV Scattering cross section Production yield Y=3.4x10 5 /sec for I=10 6 /sec/eV and N t =1g/cm 2 Counting rate R ～ 60 cps for  ～ 10 -5 (3m, 1%) and N=20