ABSTRACT

What we call here “sapphire cells” are clamped panoramic cells which have a capacity of 5-25 tonnes and which are usually equipped with large gem-stone anvils of 5-15 mm diameter. In practice, anvils of this size are almost always sapphire, but may as well be of moissanite or zirconia. There seems to be no clear agreement on the naming of such cells. What is clear is that historically the first design emanated from the Kurchatov Institute in Moscow where such cells were made of CuBe and used by Somenkov and collaborators for high pressure neutron scattering at the local reactor. The technology was then exported to the Laboratory Le´on Brillouin LLB (Saclay, France) by Somenkov and Goncharenko who used them extensively at the Saclay neutron source ORPHE´E for low-temperature powder neutron scattering measurements and called them “Kurchatov-LLB cells” from the mid-1990’s on. Apparently parallel to these developments Ahsbahs and Kuhs in Germany experimented with sapphire anvils of various shapes with the aim to carry out single-crystal neutron diffraction measurements on ferroelectrics, both at ambient and low temperatures. These cells were also clamps with a panoramic view onto the sample to maximize the available Q-space, and hence resembled in many aspects the Russian design, in particular the later design which uses sapphire spheres as anvils. The Russian neutron scattering community at the Dubna reactor continues to use these cells and calls them simply “sapphire cells,” and we adopt this nomenclature throughout this book.