OBSERVATION OF CONTINUOUS X-RAY SPECTRA MINGLED WITH ATOMIC BREMSSTRAHLUNG AND NUCLEAR BREMSSTRAHLUNG K.ISHII, T.SATOH, S.MATSUYAMA, H.YAMAZAKI, Y.TOHKAI, A.SUGIMOTO, K.YAMAMOTO, AND S. FUTATSUKAWA* Department of Quantum Science and Energy Engineering, Graduate School of Engineering and *Nishina Memorial Cyclotron Center, Japan Radioisotope Association. We measured continuum x-rays from an aluminum target bombarded with a few MeV proton beams and obtained continuous x-ray spectra mingled with atomic bremsstrahlung and nuclear bremsstrahlung. Continuous x-ray production cross sections for such x-ray spectra are discussed on the basis of PWBA theory and are compared with our experimental results. It is found that the range of x-ray energy region where the atomic bremsstrahlung and the nuclear bremsstrahlung compete together is about 5 keV.