A High Resolution X-ray Fluorescence Detector

描述(由申请人提供)： BiSync的报告一再强调，开发更好的XAS探测器系统对于解决探测器落后于同步加速器源的问题至关重要。探测器遇到的瓶颈有两个方面：一个是探测器计数速率的限制，另一个是为了检测非常稀薄的系统而限制的背景拒绝率。通过多层分析仪阵列检测器(MAAD)的研制，有效地提高了计数率，从而提高了荧光检测的效率。现在，我们建议通过开发多层分析器对阵列检测器(MAPAD)来大幅提高拒绝率。我们的第一阶段项目表明，这样的探测器可以制造出高拒绝率和合理的吞吐量。采用一次和二次多层膜的两级截留，截留率将超过200倍，处理量为15%至20%。对于28个双多层对，探测器在6keV时将收集近2%的总立体角。在非常稀薄的系统中，有效光子计数的预期增益将高达40倍。该探测器可在较大能量范围内调谐，操作方便。通过灵活的设计，该探测器可以像MAAD一样执行对抑制和单多层抑制。因此，该检测器可以覆盖从几毫米到20微米或几个百万分之大的样品稀释范围。对于痕量金属的检测，可接近的浓度可以更低。这种敏感性应该使我们能够研究新的系统，例如在体内检查与生物有关的金属，以及环境、材料、物理和化学研究中的非常稀薄的系统。该探测器具有很好的市场潜力，有利于高通量光束线的有效利用。通过将XAS技术扩展到新系统，该探测器可能会进入新的市场。

DESCRIPTION (provided by applicant): It has been repeatedly emphasized in the BioSync Report that the development of better XAS detector systems is critical in solving the problem of detectors lagging behind synchrotron sources. The detector bottleneck encountered is in two areas: one is detector count rate limitation, and the other is its limited rejection rate of background in order to examine very dilute systems. By the development of the multilayer analyzer array detector (MAAD), we effectively increased the count rate, and therefore the efficiency of fluorescence detection. Now, we are proposing to largely increase the rejection rate by developing muitilayer analyzer pair array detectors (MAPAD). Our Phase I project has shown that such a detector can be made with a high rejection rate and a reasonable throughput. With two-stage rejection of primary and secondary multilayers, the rejection rate will exceed 200 times with a 15 to 20% throughput. With 28 double multilayer pairs, the detector will collect close to 2% total solid angle at 6 KeV. The anticipated gain on the effective photon counts will be as high as 40 times on very dilute systems. The detector can be made tunable in a large energy region, and easy to operate. With a flexible design, the detector can perform the pair rejection as well as the single multilayer rejection, just like a MAAD. Thus the detector can cover a large sample dilution range from a few mM down to 20 microM or a few ppm. For trace metal detection, the approachable concentration can go even lower. This kind of sensitivity should enable us to approach new systems, such as the examination of biological relevant metals in vivo as well as very dilute systems in environmental, material, physical and chemical research. The detector has a very good market potential benefiting efficient use of high flux beamlines. By expanding the XAS technique to new systems, the detector can potentially enter into new markets.