Nuclear resonance fluorescence measurements by quasi-monochromatic, linearly polarized photon beams

Shizuma, Toshiyuki; Hayakawa, Takehito; Ogaki, Hideaki; Toyokawa, Hiroyuki*; Komatsubara, Tetsuro*; Kikuzawa, Nobuhiro ; Tamii, Atsushi*; Homma, Michio*; Nakada, Hitoshi*

Low-lying electromagnetic transitions can be studied by the method of nuclear resonance fluorescence (NRF). Recently, it has been shown that quasi-monochromatic, linearly polarized photon beams from inverse laser Compton scattering has considerably increased experimental sensitivity and to enable one to detect the fine structure of relatively weak M1 transitions. In this report, results of the NRF measurements on nuclei around lead and iron region will be presented. The M1 resonance below the neutron separation energy is resolved in to individual transitions. The experimental results are compared with theoretical predictions based on self-consistent RPA and Shell model calculations. The role of the tensor interaction in giant M1 resonance region is discussed.