SQUID-based Readout Systems for Cryogenic Dark Matter Detectors

广泛的观测告诉我们，宇宙中大约85%的物质不是由普通粒子组成的，而是以某种黑暗的形式存在。破译这种暗物质的性质对宇宙学、天体物理学和粒子物理学具有根本的重要性。一个主要的假设是，它是由弱相互作用大质量粒子（WIMP）组成的，这些粒子是在大爆炸后产生的。这样的粒子将代表粒子物理学标准模型的延伸，例如超对称性或额外维度。如果WIMP存在并且是暗物质，那么它们在我们银河系中的存在可以通过地面探测器中原子核的散射来检测。低温暗物质搜索（CDMS）合作率先使用低温声子介导的设备来检测核上WIMP的罕见散射，并将这些事件与其他背景相互作用区分开来。将低温锗技术缩放到更大质量的许多关键技术要求之一是改进声子和电离信号的低温前置放大器。几年前，通过该小组的努力，生产和评估了目前苏丹设施中使用的超导量子干涉器件（SQUID）前置放大器，该小组一直是在苏丹各种CDMS实验的整个操作过程中优化其性能的合作中不可或缺的成员。该奖项将在四个互补方向上支持CDMS计划的科学方面，并在合作范围内充分协调：（a）支持超级清洁发展机制-苏丹试验（参与苏丹实验的操作，特别是声子读出系统的监督和维护），（B）对SuperCDMS-SNOLAB的设计作出贡献（c）对SuperCDMS-SNOLAB结构的科学支持（SuperCDMS-SNOLAB SQUID和室温电子器件的生产测试），以及（d）&对GEODM（基于SQUID的电离读出）的长期研发。低温读出系统的持续发展是SuperCDMS和GEODM计划科学目标的关键组成部分。更广泛的影响该计划的技术发展也将推动声子介导探测器的发展，其应用日益广泛。该计划还将支持物理和电气工程学生的教育和培训。

A broad range of observations tell us that about 85% of the matter in the universe is not made of ordinary particles, but exists in some dark form. Deciphering the nature of this dark matter is of fundamental importance to cosmology, astrophysics, and particle physics. A leading hypothesis is that it is comprised of Weakly Interacting Massive Particles (WIMPs) that were produced moments after the Big Bang. Such particles would represent an extension of the Standard Model of particle physics, such as supersymmetry or additional dimensions. If WIMPs exist and are the dark matter, then their presence in our Milky Way may be detectable via scattering from atomic nuclei in a terrestrial detector. The Cryogenic Dark Matter Search (CDMS) Collaboration has pioneered the use of low-temperature phonon-mediated devices to detect the rare scattering of WIMPs on nuclei and to distinguish these events from other background interactions. One of many key technological requirements for the scaling to greater mass of the low-temperature germanium technology is improvement in the cryogenic preamplifiers of both phonon and ionization signals. The superconducting quantum interference device (SQUID) preamplifiers used in the present Soudan facility were produced and evaluated through the efforts of this group several years ago, and the group has been an integral member of the collaboration in optimizing their performance throughout the operation of the various CDMS experiments at Soudan. This award will support the scientific aspects of the CDMS programs in four complementary directions, fully coordinated within the collaboration: (a) support of the SuperCDMS-Soudan experiment (participating in operation of the Soudan experiment, particularly oversight and maintenance of the phonon readout system), (b) contribution to the design of SuperCDMS-SNOLAB (design optimization of cold hardware and electronics), (c) scientific support to SuperCDMS-SNOLAB construction (production testing of SuperCDMS-SNOLAB SQUIDs and room-temperature electronics), and (d) long-term R&D towards GEODM (SQUID-based ionization readout). Continued development of the cryogenic readout systems is a critical component of the science goals of the SuperCDMS and GEODM programs.Broader ImpactsThis program's technological development will also push the envelope of phonon-mediated detectors, the applications of which are increasingly widespread. This program will also support the education and training of physics and electrical engineering students.