Request for continued operation and study of the ZEPLIN II dark matter detector

请求继续运行和研究 ZEPLIN II 暗物质探测器

• 批准号: 0653459
• 负责人: Hanguo Wang
• 金额: --
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0653459&HistoricalAwards=false
• 关键词: Request; continued; operation; study; ZEPLIN

Large scale astronomical observations, including expansion, galaxy clustering, gravitational lensing and microwave background, indicate that the universe is dominated by unidentified dark matter whose total mass exceeds that of normal (baryonic) matter by a factor 5-10. A favored dark matter candidate is a massive particle interacting only weakly with normal matter but nevertheless producing rare nuclear recoils detectable in suitable targets such as liquid xenon.This UCLA group requests funding for the continued running and performance improvements for the 32 kg two-phase ZEPLIN II liquid Xenon dark matter detector which is now running in the UK Boulby Mine. The program is based on a new technique for identifying low energy nuclear recoils from dark matter collisions, using scintillation and ionization processes in liquid xenon. After completion of laboratory tests in 2005, the detector was installed underground and initial runs with neutron and gamma sources show primary S1 and secondary S2 scintillation pulses in accordance with expectation, and with neutron and gamma populations having different mean values of the parameter S2/S1. New work needed includes the investigation and prevention of radon influx into the detector, removal of radon decay products from interior surfaces, improvements to data acquisition, improved event selection, and reduction of energy threshold by a more efficient trigger. The detection of particle dark matter would open a new window in astronomy and particle physics, with more advanced detectors able to determine both details of the particle properties and the spectrum and flow of the dark matter in our Galaxy. It will thus transform and extend world activities in the particle physics and astronomical communities. Moreover, the techniques themselves can be further scaled up and applied to other fundamental experiments such as double beta decay, and solar neutrinos. As with other particle detection techniques, new methods of position sensitivity and particle discrimination may give rise to new medical diagnostic techniques.

大规模的天文观测，包括膨胀，星系聚类，重力透镜和微波背景，表明宇宙由未识别的暗物质主导，其总质量超过正常（Baryonic）物质的宇宙以5-10因子为单位。 一个受欢迎的暗物质候选者是一个巨大的粒子，仅与正常物质相互作用，但仍会在诸如液体Xenon之类的合适目标中检测到稀有的核后坐力。该UCLA组要求为32 kg两阶段的Zeplase Zeplase Zeplasi II液体Xenon暗物质检测器的持续运行和性能改善提供资金，该探测器现在在英国英国boul Boul Boul Boul Boul Boul Boul Boul Boul Boul Boul Boul Boul Boul by。该程序基于一种新技术，用于使用液体氙气闪烁和电离过程来鉴定暗物质碰撞中的低能核后坐力。在2005年完成实验室测试后，将检测器安装在地下，并以中子和伽马来源的初始运行显示了原发S1和次级S2闪烁脉冲，并根据预期，中子和伽玛群体具有不同的参数S2/S1的平均值。 所需的新工作包括调查和预防ra涌入检测器，从内部表面清除ra衰减产物，改进数据获取，改善事件选择以及通过更有效的触发触发降低能量阈值。粒子暗物质的检测将打开天文学和粒子物理的新窗口，更高级的检测器能够确定我们银河系中粒子特性的细节以及暗物质的光谱和流动。因此，它将改变和扩展粒子物理和天文社区中的世界活动。此外，这些技术本身可以进一步扩展并应用于其他基本实验，例如双β衰变和太阳中微子。与其他粒子检测技术一样，位置灵敏度和粒子歧视的新方法可能会引起新的医学诊断技术。