RUI: Detection of Dark Matter with Moderately Superheated Liquids

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。天体物理学中最经久不衰的谜团之一是如何解释一个令人信服的证据：在几乎所有高于恒星大小的尺度上，以看不见的形式存在的引力物质，远远超过所有已知类型的辐射所能探测到的物质。这种“暗物质”是通过其对星系、星系团和宇宙中更大规模结构的结构的影响而动态检测到的。亚原子粒子标准模型的一般扩展预测了弱相互作用大质量粒子的存在，这些粒子是暗物质的极好候选者。预计这些粒子与普通物质的相互作用与中微子一样罕见，因此很难被探测到。COUPP和PICASSO小组已经着手开发新的大型暗物质探测器，这些探测器来自于众所周知的气泡室技术。带电粒子穿过气泡室中过热的流体，产生热量，产生小气泡。这些气泡爆炸性地膨胀，除非腔室迅速加压。在加压之前，可以对气泡进行拍照，以显示这些颗粒的路径，因此该腔室是微小颗粒信号的绝佳放大器。这两种方法都使过热状态持续了足够长的时间来寻找暗物质。这一奖项将使该组织能够继续参与这些努力。IUSB已经生产的声音传感器最近被证明对丢弃宇宙射线引起的事件和区分中等过热流体（α粒子）关注的唯一放射性信号很有用。该计划更广泛的影响包括加强本科生的教育。他们参与声学换能器的设计、建造和表征、放射性测量和其他实验项目。PI已经开始与当地一所高中合作，为高中生提供科学实验体验。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). One of the most enduring mysteries in astrophysics is the explanation for the compelling evidence that, on virtually all scales above the size of a star, far more gravitating material exists in an invisible form than that which can be detected by all known types of radiation. This "dark matter" is detected dynamically, through its effects on the structuring of galaxies, clusters of galaxies and larger scale structures in the universe. Generic extensions of the standard model of subatomic particles predict the existence of Weakly Interacting Massive Particles which are excellent candidates for the dark matter. These are expected to interact with ordinary matter as rarely as neutrinos and thus be extremely difficult to detect.The COUPP and PICASSO groups have undertaken the development of new large dark matter detectors derived from the well known bubble chamber technique. Charged particles traversing the superheated fluid in bubble chambers deposit heat which creates small bubbles of gas. These bubbles expand explosively unless the chamber is quickly pressurized. The bubbles can be photographed before pressurization revealing the paths of these particles, so the chamber is an excellent amplifier of tiny particle signals. Both approaches have made the superheated state long lived enough to search for dark matter. This award will enable this group to continue its participation in these efforts. The sound sensors already produced by IUSB have recently proven to be useful for discarding cosmic ray induced events and distinguishing the only radioactive signal of concern for moderately superheated fluids (alpha particles). The broader impacts of the program include enhancing the education of undergraduates. They participate in the design, construction and characterization of acoustic transducers, measurement of radioactivity and other projects for the experiments. The PI has started to work with one local high school to provide high school students with science experiment experiences.