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The conceptual design for a nonscaling fixed field alternating gradient accelerator suitable for charged particle therapy (the use of protons and other light ions to treat some forms of cancer) is described.

We have measured the magnetization, low-temperature heat capacity and electrical resistivity of the binary quasicrystal YbCd 5.7 and its crystalline approximant, cubic YbCd 6 . Magnetization data reveal that Yb ions are divalent in both compounds. The coefficient of the linear term in the heat capacity, γ , is 51 and 7.5 mJ mol −1 K −2 in YbCd 6 and YbCd 5.7 , respectively. The heat capacity data thus reveal a significant reduction in the electronic density of states in the quasicrystalline phase. However, the Debye temperatures of the two compounds are comparable; 144 and 138 K, respectively. The electrical resistivity of YbCd 6 shows typical metallic behaviour while the resistivity of YbCd 5.7 , larger than that of YbCd 6 , is characterized by a negative temperature coefficient below 300 K with a peak around 50 K.

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