Upgrade of a Ruby-Fluorescence System

小行星9725898 这笔赠款提供部分支持，以升级红宝石荧光光谱仪在加州大学伯克利分校的高压实验室与电荷耦合器件（CCD）。 红宝石荧光光谱仪用于快速测定金刚石压砧单元（DAC）内非常小的样品（50-500微米）的压力和压力变化。 精确确定DAC内的压力分布允许计算单元内的剪切应力和/或已经与高压DAC实验结合激光加热的材料的粘性应力松弛。 加州大学伯克利分校红宝石荧光系统的当前检测器是一个过时的光电倍增管（PMT），已超过其估计的10年。寿命 新的PMT目前仅在定制的基础上制造，因此随着数字CCD进入市场并变得更便宜，这些年来价格有所增加。 虽然仍然比CCD检测器便宜，但PMT对发射的EM辐射的敏感性低得多，并且不能用于需要超过60-70 GPa的压力的实验中，其中样品尺寸必须非常小，因此发射的荧光很弱。 因此，PMT探测器将高P-T实验限制在上地幔条件下。 另外，CCD阵列可随后适用于拉曼光谱学 红宝石荧光光谱仪是DAC实验中必需的工具，PI选择CCD检测器来取代PMT是合理的，具有前瞻性。 这次升级将使这位PI，他的学生和同事能够继续进行旨在了解早期地球和行星分化以及高压地幔相和合成材料结构的挑衅性研究。 ***

9725898 Jeanloz This grant provides partial support to upgrade the ruby fluorescence spectrometer at the UC-Berkeley high-pressure laboratory with a charge-coupled device (CCD). The ruby fluorescence spectrometer is used to rapidly determine pressure and pressure variations across very small samples (50-500 microns) inside diamond anvil cells (DAC). Accurate determination of the pressure distribution within a DAC allows calculation of shear stresses within the cell and/or viscous stress relaxation of materials that have been laser heated in conjunction with high pressure DAC experiments. The current detector for UC-Berkeley ruby fluorescence system is an antiquated photomultiplier tube (PMT) that has exceeded its estimated 10 yr. life span. New PMT's are currently manufactured on a made-to-order basis only and have therefore increased in price over the years as digital CCD's have entered the market and become more affordable. While still less expensive than CCD detectors, PMT's are far less sensitive to emitted EM radiation and cannot be used in experiments requiring pressures exceeding 60-70 GPa where sample sizes are necessarily very small and emitted fluorescence is therefore weak. PMT detectors thus limit high P-T experiments to upper mantle conditions. Additionally, a CCD array can later be adapted for use in Raman spectroscopy A ruby fluorescence spectrometer is a required tool in DAC experimentation and the PI's choice of a CCD detector to replace his PMT is well reasoned and forward looking. This upgrade will allow this PI, his students and colleagues to continue provocative research aimed at understanding early Earth and planetary differentiation and the structure of high pressure mantle phases and synthetic materials. ***