@article{,
    author = {Maier-Komor, Paul; Altarev, Igor; Bergmaier, Andreas; Böni, Peter; Dollinger, Günther; Krücken, Reiner; Paul, Stephan; Schott, Wolfgang},
    title = {Antireflection foils with multi-layer converter for ultracold neutron detectors},
    editor = {Green, J. P.; Maier-Komor, Paul},
    booktitle = {},
    series = {},
    journal = {Nuclear Instruments and Methods in Physics Research Section A},
    address = {},
    publisher = {},
    edition = {},
    year = {2004},
    isbn = {},
    volume = {521},
    number =  {1},
    pages = {242-246},
    url = {http://www.sciencedirect.com/science/article/pii/S0168900203030936},
    doi = {10.1016/j.nima.2003.11.179},
    keywords = {Annealing ; Cryogenics ; Electron beams ; Evaporation ; Gravitational effects ; Metal foil ; Neutron sources ; Reflection ; Titanium ; Vacuum applications, Electron beam evaporation ; Multi-layer targets ; Neutron detectors},
    abstract = {For experiments at the ultracold neutron (UCN) source of the new high-luminosity neutron source, Forschungsreaktor München II (FRM II), highly efficient detectors are needed. The desired type of detectors utilizes 6Li as the neutron converter based on the huge cross-section reaction 6Li(n; α)t and detection of the 2.06MeV α-particles or the 2.73MeV t-particles. The high reflectance of UCN from 6Li with its positive optical potential must be compensated by a material with negative optical potential. Instead of the expensive 62Ni material, natural Ti can be chosen. It was demonstrated that neither 6Li metal nor Ti metal can be deposited in a high-vacuum evaporation apparatus without creating a positive optical potential and thus increasing the reflectivity for the UCN due to oxygen impurities coming from the H2O partial pressure in the high-vacuum system. To overcome these problems, a new UHV evaporation apparatus was developed and built which is capable of reaching a vacuum in the 10-10 Pa range. Such a good vacuum can be obtained only when annealing the vacuum system up to 470K. At such a high annealing temperature the silicon detectors for the α- and t particles might suffer degradation of their energy resolution. Therefore, the multi-layer system of 6Li and natTi is not deposited directly on the silicon detector but a thin rolled Ti foil is applied as backing. A test deposition of 200 double layers of 6LiF/ 62Ni on a thin Ti foil is described and a report is given about the setup of the new UHV evaporation apparatus.},
    note = {},
    institution = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
    
    
}