a New Design for Diamond Window Equipped Paris-Edinburgh — First Tests and Results

High pressure cells of the Paris-Edinburgh type are important tools for experimental high pressure studies in material science. Although these cells were originally developed for use in neutron diffraction, today they are also applied in alternative experimental high pressure fields. Their main advantages are their small construction size, limited weight and the relative high reachable pressures with a maximized sample volume. The small construction size also results in very good cost efficiency. The major drawback of these cells is that due to their simple squeezer geometry pressure extrapolations are nearly impossible and, hence, the use of internal standard is mandatory. Consequently, the normal use of Paris-Edinburgh cells is mostly limited to experiments with neutron or synchrotron radiation, during which pressure and temperature are determined by using an internal diffraction standard. To overcome this problem, tone may combine the advantages of diamond anvil cells with those of Paris-Edinburgh-cells by integrating diamond windows into the upper and / or the lower anvil. With such a cell it is possible to retrieve pressure and / or temperature data by measuring the shift of Raman bands or fluorescence lines by spectroscopic methods. Several attempts have been made to build such a cell ([1] and Klotz pers. communication) using different window materials. Until now no final setup has been published. We present a new Paris-Edinburgh cell design especially constructed for use within high energy relativistic heavy ion radiation experiments. This design uses conventional diamond anvils as spectroscopic windows in conjunction with specially designed hardened steel anvils. We have performed first feasibility studies up to 2.5 GPa with a standard Raman spectrometer using a special adapted Raman glass fiber probe. We present results of several mechanical test runs and one experiment with relativistic heavy ion radiation at the GSI Helmholtzzentrum für Schwerionenforschung (Darmstadt, Germany). In addition we discuss observed mechanical damage of the anvil structure and future design developments. [1] M. J. Lipp, W. J. Evans, C. S. Yoo (2005) Report, UCRL-JRNL-214303.