• D. Saez de Jauregui, S. Casalbuoni, A.W. Grau, M. Hagelstein, E.M. Mashkina
  FZK, Eggenstein
• R. Cimino, M. Commisso
  INFN/LNF, Frascati (Roma)
• R. Weigel
  Max-Planck Institute for Metal Research, Stuttgart

Recent investigations with the cold bore superconducting undulator installed at ANKA indicate that the main contribution to the beam heat load is caused by electron bombardment. For a quantitative understanding of the problem a cold vacuum chamber for diagnostics has been designed. Among other important parameters (heat load, pressure, etc) this device shall monitor the spectrum of the low energy electrons bombarding the wall. In this contribution we report on the measurements of the spectrum of the low energy electrons bombarding the wall of the cold vacuum chamber in a room temperature region of the ANKA storage ring performed using a in house developed retarding field analyzer (RFA). The calibration of the RFA performed at the national laboratories of Frascati is also described.