The source-sample stage of the new two-dimensional angular correlation of annihilation radiation spectrometer at Technische Universität München.

نویسندگان

  • Hubert Ceeh
  • Josef Andreas Weber
  • Michael Leitner
  • Peter Böni
  • Christoph Hugenschmidt
چکیده

Angular correlation of annihilation radiation (ACAR) is a well established technique for the investigation of the electronic structure. A major limitation of ACAR studies is the available positron flux at a small spot on the sample. For this reason, the focus of this work is put on the discussion of a newly developed source-sample stage of the new 2D-ACAR spectrometer at Technische Universität München which uses an optimized static magnetic field configuration to guide the positrons onto the sample. The achieved spot diameter is d(FWHM) = 5.4 mm, with a high efficiency over the whole energy spectrum of the (22)Na positron source. The implications of the performance of the source-sample stage are discussed with regard to 2D-ACAR measurements of single crystalline α-quartz, which serves as a model system for the determination of the total resolution. A value of (1.53 × 1.64) mrad(2) FWHM was achieved at room temperature.

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عنوان ژورنال:
  • The Review of scientific instruments

دوره 84 4  شماره 

صفحات  -

تاریخ انتشار 2013