The Role of Vitamin D in Osteoarthritis and Rheumatic Disease

Boron carbide coatings for neutron detection probed by x-rays, ions, and neutrons to determine thin film quality

“…Material analysis by means of X-ray-Photoelectron Spectroscopy, Secondary-Ion-Mass-Spectrometry, and RutherfordBack-Scattering (RBS) revealed low impurities concentration in the coatings. The isotope composition determined by Secondary-Ion-Mass-Spectrometry, RBS, and inelastic nuclear reaction analysis of the converter coatings evidences almost identical 10 B isotope contents in the sputter target and in the deposited coating. Neutron conversion and detection test measurements with variable irradiation geometry of the converter coating demonstrate an average relative quantum efficiency ranging from 65% to 90% for cold neutrons as compared to a black 3 He-monitor.…”

“…Unfortunately, the isotopes 155 Gd and since the generation of 3 He as a byproduct of nuclear weapons storage is ceasing, its availability is nowadays very limited and consequently 3 He is becoming increasingly expensive; 9,10 the price raises continuously (nowadays: >2500 $/(bar liter)). Furthermore, research activities in other fields like on fusion reactors for energy generation by aneutronic nuclear fusion will need in the near future substantial amount of 3 He for the D þ 3 He !…”

“…These concepts require development in thin film deposition technique regarding high adhesion, thickness uniformity and chemical purity of the converter coating on large area substrates. We report on the sputter deposition of highly uniform large-area 10 B 4 C coatings of up to 2 lm thickness with a thickness deviation below 4% using the Helmholtz-Zentrum Geesthacht large area sputtering system. The 10 B 4 C coatings are x-ray amorphous and highly adhesive to the substrate.…”

“…Alternative neutron detection concepts, therefore, have been invented based on solid 10 B converters. These concepts require development in thin film deposition technique regarding high adhesion, thickness uniformity and chemical purity of the converter coating on large area substrates.…”

“…The most common isotopes used for neutron detection are 3 He, 6 Li, 10 B, 155 Gd, and 157 Gd. Unfortunately, the isotopes 155 Gd and since the generation of 3 He as a byproduct of nuclear weapons storage is ceasing, its availability is nowadays very limited and consequently 3 He is becoming increasingly expensive; 9,10 the price raises continuously (nowadays: >2500 $/(bar liter)).…”