Upgrade of a Ruby-Fluorescence System

9725898 Jeanloz这笔赠款提供部分支持，用于升级加州大学伯克利分校高压实验室的红宝石荧光光谱仪，并安装电荷耦合器件。红宝石荧光光谱仪用于快速测定钻石顶锤单元(DAC)内非常小的样品(50-500微米)的压力和压力变化。通过准确确定DAC内的压力分布，可以结合高压DAC实验计算单元内的剪切应力和/或激光加热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目前的探测器是一个过时的光电倍增管(PMT)，已经超过了其估计的10年。寿命。新的光电倍增管目前只在定做的基础上生产，因此随着数字电荷耦合器件进入市场并变得更加负担得起，多年来价格有所上涨。虽然光电倍增管的价格仍然低于CCD探测器，但它对发射的电磁辐射的敏感度要低得多，不能用于需要超过60-70 Gpa的压力的实验，因为在这些实验中，样品大小必须非常小，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。此外，稍后还可以改装用于拉曼光谱的CCD阵列红宝石荧光光谱仪是DAC实验中的必要工具，PI选择CCD探测器来取代他的PMT是有充分理由和前瞻性的。这次升级将使这位PI、他的学生和同事们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. ***