COMPTON SCATTERING STUDY OF ELECTRONIC STATE IN METALS UNDER HIGH PRESSURE. G.[[opthyphen]]Oomi¹, T.[[opthyphen]]Kagayama¹, F.[[opthyphen]]Itoh², H.[[opthyphen]]Sakurai², H.[[opthyphen]]Kawata³ and O.[[opthyphen]]Shimomura³. ¹Department[[opthyphen]]of[[opthyphen]]Physics, Faculty[[opthyphen]]of[[opthyphen]]General[[opthyphen]]Education, Kumamoto[[opthyphen]]University, Kumamoto[[opthyphen]]860, JAPAN; ²Department [[opthyphen]]of[[opthyphen]]Electrical[[opthyphen]]Engineering, Gunma[[opthyphen]]University, Kiryu, Gunma[[opthyphen]] 376, JAPAN; ³Photon[[opthyphen]]Factory, National [[opthyphen]]Laboratory [[opthyphen]]for[[opthyphen]]High[[opthyphen]]Energy [[opthyphen]]Physics, Tsukuba, Ibaraki[[opthyphen]]305, JAPAN

In the study of the electronic structure of metals and alloys (MA), it is the most essential to know the Fermi surface or the momentum distribution of conduction electrons because almost all the physical properties of MA are dominated by the behaviors of conduction electrons. The Compton scattering is well known to be a good technique to get the Fermi surface.

Pressure is also a good tool to investigate the electronic structure of MA since we can observe a lot of electronic (phase) transition by applying pressure. However there have been a few reports to study the Fermi surface under high pressure. The reason for that is mainly the technical difficulty and for Compton scattering, the lack of X(g)-ray source intensity. Recently we can obtain the high intense X-ray by using synchrotron radiation (SR). Thus it is very interesting to apply the Compton scattering techniques to the investigation of electronic structure of MA under high pressure by using SR.

In the present work metallic Li was used as a sample because the contribution from core electron to Compton profile is small. Compton scattering measurement was carried out by using 59.34[[opthyphen]]keV X-ray (Tm-K[[opthyphen]]edge) from SR. The scattered X-ray was detected by means of solid state detector. The preliminary result at ambient pressure confirmed that we can use the optical system constructed in this work for the measurement of Compton profile at high pressure.