Development of a Cantilever Magnetometer for Pulsed Magnetic Fields

小行星9704025 将研制一种用于脉冲磁场的高灵敏度悬臂梁磁强计。 预计该装置将在高达100 T的磁场中实现10-12 Am 2（10-9 emu）量级的灵敏度，从而超过传统检测方法的灵敏度2至3个数量级。 该项目的动机是在最高可用磁场中对物理现象进行热力学研究，目前只能在持续时间为10-2至1秒的瞬态脉冲场中获得。 目前，脉冲场的实验仅限于磁输运、磁光和磁化率的研究。 对于后者，通常采用感应方法，其中在多匝线圈中感应与磁矩相对于磁场的导数成比例的电压。 如果对该磁化率信号AC=dm/dH进行积分，则获得关于磁矩m的信息，其对磁矩的典型灵敏度为10-8至10- 9Am 2或10-5至10-6 emu。 随着悬臂梁磁强计的脉冲场制度的成功发展，一个非常显着的改进，这种电感方法可以实现。 %%% 在这个项目中，我们将设计，制造和测试各种悬臂设备配置，特别是在长（~10-1 s）和短（~10-2 s）脉冲磁场中使用。 将组装一个低场脉冲系统，用于新设备的局部时间表征，并在洛斯阿拉莫斯国家实验室的国家高磁场实验室脉冲场设施进行全面表征。 如果这个项目成功，它将大大提高大量和越来越多的研究人员与脉冲磁场的测量能力，通过使敏感的磁力测量技术接近100 T的领域的各种物理系统。 项目成功完成后，新设备将在NHMFL @ LANL提供给用户。 因此，它有可能使凝聚态科学的许多研究人员受益。 此外，将这一技术转让给工业界的潜力很大。 ***

9704025 Naughton A highly sensitive cantilever magnetometer will be developed for use in pulsed magnetic fields. It is anticipated that this device will achieve a sensitivity of order 10-12 Am2 (10-9 emu) in fields up to 100T, thus exceeding the sensitivity of conventional detection methods by 2 to 3 orders of magnitude. The motivation for this project is the thermodynamic study of physical phenomena in the highest available magnetic fields, which are now obtained only in transient, pulsed fields of 10-2 to 1 second duration. At the present time, experiments in pulsed fields are restricted to studies of magnetotransport, magneto- optics, and magnetic susceptibility. For the latter, an inductive method is usually employed, wherein a voltage proportional to the derivative of the magnetic moment with respect to magnetic field is induced in a multi-turn coil. If one integrates this susceptibility signal AC=dm/dH, one obtains information about the magnetic moment m, with typical sensitivity to moment of 10-8 to 10-9 Am2, or 10-5 to 10-6 emu. With the successful development of a cantilever magnetometer for the pulsed field regime, a very significant improvement over this inductance method can be realized. %%% In this project, we will design, fabricate and test a variety of cantilever devices configured especially for use in long (~10-1 s) and short (~10-2 s) pulse magnetic fields. A low field pulse system will be assembled for local temporal characterization of the new devices, with full characterization taking place at the National High Magnetic Field Laboratory's Pulsed Field Facility at Los Alamos National Laboratory. If this projects succeeds, it will significantly enhance the measurement capabilities of a large and growing number of investigators working with pulsed magnetic fields, by making sensitive magnetometry an accessible technique to a variety of physical systems in fields approaching 100T. Upon successful completion of the project, t he new devices will be made available to users at the NHMFL @ LANL. It therefore has the potential to benefit many researchers in the condensed matter sciences. In addition, there is significant potential for the transfer of this technology to industry. ***