国内的暗物质探测：中国锦屏地下实验室的未来发展
<p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">2010 年CJPL-Ⅰ建成后开展了CDEX 和PADAX 两个研究组的暗物质实验并取得了可喜的重要研究成果，极大地推动了我国暗物质侦测的基础前沿研究，使我国的暗物质直接探测实验在短短几年内进入国际暗物质研究前列。</p><div class="pgc-img" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><img src="https://p1-tt.byteimg.com/origin/pgc-image/81ae6f7e1be34e39b4ae4ac219dc7a6c" img_width="533" img_height="300" alt="国内的暗物质探测：中国锦屏地下实验室的未来发展" inline="0" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; border-style: none; max-width: 100%; display: block; margin: 10px auto;"><p class="pgc-img-caption" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; text-align: center; font-size: 12px; color: rgb(119, 119, 119); line-height: 16px;"></p></div><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">由于CJPL 有最厚的岩石覆盖，低辐射本底的岩石结构，再加上便利的隧道通行及完善的工作和生活设施，使得CJPL 有可能成为国际一流的地下实验室。CJPL 受到国内外科学界的极大关注，世界上很多科学家都到CJPL-Ⅰ参观学习，了解情况，并希望能够借助CJPL 得天独厚的实验条件开展各类低本底或稀有事件的实验。</p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">CJPL-Ⅰ的总容积仅4000m3，远不能满足国内外极深地下实验的空间要求。为满足国内外学界的热烈期望，规划建设一个更大空间、容纳更多实验的CJPL 二期项目，成为学界共识。图5.3.1 为国内外专家CJPL 二期项目研讨会的照片。为满足学界的要求，清华大学和雅砻江流域水电开发有限公司决定共同建设空间更大的中国锦屏地下实验室CJPL-Ⅱ。中国锦屏地下实验室二期项目规划建设总容积约13 万m3，由洞径为14m×14m，长约65m 的8 个通用型实验空间组成。</p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">CJPL-Ⅱ将成为国际上最深，空间最大，也是条件最好的地下实验室，也必将成为我国优良的深地实验平台和辐射本底极低实验领域的新基地，全面促进我国相关领域的研究。</p><div class="pgc-img" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><img src="https://p1-tt.byteimg.com/origin/pgc-image/7eba6737be044554888b247ada43355b" img_width="488" img_height="343" alt="国内的暗物质探测：中国锦屏地下实验室的未来发展" inline="0" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; border-style: none; max-width: 100%; display: block; margin: 10px auto;"><p class="pgc-img-caption" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; text-align: center; font-size: 12px; color: rgb(119, 119, 119); line-height: 16px;">图5.3.1 国内外专家CJPL 二期项目研讨会</p></div><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><strong style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; font-weight: 700;">建设规划设计</strong></p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">CJPL-Ⅱ的主实验区包括4 组8 个实验区及其辅助设施，空间总容积达13 万m3。图5.3.2 所示为CJPL-Ⅱ建设规划设计图，从中不难看出CJPL-Ⅱ在锦屏山隧道中的位置。</p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">图中暗红色粗直线为4 条用于发电的大直径通水管；绿色A,B 为两条贯穿锦屏山的交通隧道（俗称交通洞），全长17.5km，CJPL-Ⅰ就位于A 交通隧道的中心；白色为排水隧道；深蓝和浅蓝色分别是为加快施工而开挖的辅助隧道（俗称辅助洞）。水电建设完工后，两条辅助隧道将废弃不用。 CJPL-Ⅱ将借助于辅助隧道（深蓝）建设4 组8 个实验区（图中用鲜红色表示）。每个实验室长65m，高14m，宽14m。每个实验室都和辅助隧道连接。 实验人员或实验设备可从交通隧道经辅助隧道进入实验室。 实验室之间也开挖了隧道将其连通。</p><div class="pgc-img" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><img src="https://p1-tt.byteimg.com/origin/pgc-image/806b4c1c900e454b9004ba9f4af44ea2" img_width="512" img_height="333" alt="国内的暗物质探测：中国锦屏地下实验室的未来发展" inline="0" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; border-style: none; max-width: 100%; display: block; margin: 10px auto;"><p class="pgc-img-caption" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; text-align: center; font-size: 12px; color: rgb(119, 119, 119); line-height: 16px;">图 5.3.2 CJPL-Ⅱ建设规划设计图</p></div><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">为保证实验室空气的洁净度，特别是减少有害的氡气含量，实验室将建设有空气预净化处理功能的高质量通风过滤系统。新风系统的总风量正常情况下设计为24000m3/h，峰值可达45000m3/h。此外还需建设能保证照明和实验需要的供电系统、通信和信息传输系统等。整个工程预计到2016 年完成。图5.3.3 为正在施工的CJPL-Ⅱ照片。</p><div class="pgc-img" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><img src="https://p1-tt.byteimg.com/origin/pgc-image/0f59a26c3a6244128e6a30ddc7d3cabe" img_width="468" img_height="318" alt="国内的暗物质探测：中国锦屏地下实验室的未来发展" inline="0" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; border-style: none; max-width: 100%; display: block; margin: 10px auto;"><p class="pgc-img-caption" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; text-align: center; font-size: 12px; color: rgb(119, 119, 119); line-height: 16px;">图5.3.3 正在施工的CJPL-Ⅱ</p></div><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><strong style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; font-weight: 700;">未来可能的实验</strong></p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">虽然CJPL-Ⅱ还在建设中，已经有不少很好的暗物质研究和其他稀有事件的物理研究在酝酿和计划中了，包括CDEX-Ⅱ、PANDAX-Ⅱ等。</p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">图5.3.4 所示为目前在CJPL-Ⅱ中计划安排的CDEX-Ⅱ、PANDAX-Ⅱ、JUNA 的实验室布局。此外，计划和讨论中的双β 衰变、太阳中微子实验等也都希望能在CJPL-Ⅱ中进行。</p><div class="pgc-img" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><img src="https://p1-tt.byteimg.com/origin/pgc-image/218910f2a83d405cbe85cb939594ecc2" img_width="503" img_height="273" alt="国内的暗物质探测：中国锦屏地下实验室的未来发展" inline="0" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; border-style: none; max-width: 100%; display: block; margin: 10px auto;"><p class="pgc-img-caption" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; text-align: center; font-size: 12px; color: rgb(119, 119, 119); line-height: 16px;">图5.3.4 CDEX-Ⅱ，PANDAX-Ⅱ，JUNA 等实验在CJPL-Ⅱ中的安排</p></div><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><strong style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; font-weight: 700;">1. CDEX-Ⅱ</strong></p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">CDEX-Ⅱ实验中采用高纯锗探测器阵列作为实验探测器，准备将几百千克甚至1000kg 的高纯锗阵列浸泡在近1500t 的液氮中，以实现对暗物质的高灵敏度探测。实验装置及其在CJPL 中的安排如图5.3.5 所示。</p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">液氮罐的直径约16m，高18m，计划在实验室内挖一个直径约18m、深14m 的地穴，将整个液氮罐坐放在地穴内。图中黄色部分示意高纯锗探测器阵列，蓝色为罐中的液体氮，系统工作温度为-196℃（77K）。实验大厅的地面上安排有低温制冷系统、设备吊装系统、电子学及控制系统等。虽然CDEX-Ⅱ的实验原理和装置结构与CDEX-10 类似，但规模的扩大很可能会给探测技术和工程建造带来难以预想的困难。</p><div class="pgc-img" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><img src="https://p1-tt.byteimg.com/origin/pgc-image/0345ec2a777047a79e79337c3d10a685" img_width="399" img_height="301" alt="国内的暗物质探测：中国锦屏地下实验室的未来发展" inline="0" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; border-style: none; max-width: 100%; display: block; margin: 10px auto;"><p class="pgc-img-caption" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; text-align: center; font-size: 12px; color: rgb(119, 119, 119); line-height: 16px;">图5.3.5 CJPL-Ⅱ中的CDEX-Ⅱ 探测器</p></div><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><strong style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; font-weight: 700;">2. JUNA</strong></p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">另外一项将在CJPL-Ⅱ中开展的重要实验是JUNA 一期（JUNA-Ⅰ）。</p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">JUNA 是我国首个地下核天体物理实验，该实验是对恒星演化过程中的关键核反应进行直接测量。JUNA 将使我国的核天体物理研究跻身国际领先行列。</p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">JUNA 准备在CJPL-Ⅱ的超低本底环境中，建设高强束流加速器及高分辨伽马射线能谱仪，对伽莫夫能区附近（质心系能量600keV）的12C (α,γ) 16O 核反应做直接测量。</p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">12C(α,γ)16O 核反应是天体演化中的重要反应，被称为核天体物理的圣杯。该反应在很多恒星的演化中都起着关键作用，其截面对中等质量核素铁的合成和大质量恒星后期的演化进程有决定性的影响。由于该反应在伽莫夫能区(E 0=300keV) 截面极低(10-41 cm2)，反应事例稀少，直接测量非常困难，必须在极低本底的环境下才有可能。</p><div class="pgc-img" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><img src="https://p1-tt.byteimg.com/origin/pgc-image/1c736c998e04480f9309fb416bc0ef51" img_width="606" img_height="266" alt="国内的暗物质探测：中国锦屏地下实验室的未来发展" inline="0" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; border-style: none; max-width: 100%; display: block; margin: 10px auto;"><p class="pgc-img-caption" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; text-align: center; font-size: 12px; color: rgb(119, 119, 119); line-height: 16px;">图5.3.6 JUNA 实验工作原理图</p></div><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">自20 世纪70 年代起，科学家们付出了40 多年的努力，但12C(α,γ)16O 反应在伽莫夫能区的截面数据仍远未达到理论模型要求的精度。JUNA-Ⅰ实验计划在伽莫夫能区范围开展直接测量，预计取得核天体物理领域的原创性成果，这将为理解宇宙元素起源和恒星演化提供重要的数据，也将对突破图5.3.6 所示为JUNA 实验的工作原理图。加速器将He 核加速到一定能量入射到高纯碳靶上发生反应，反应产生的伽马射线被安排在靶附近的伽马能谱仪测量。图5.3.7 所示为CJPL-Ⅱ内的部分设备安排示意图，图中左侧是加速器，中间是磁谱仪（用来对He 粒子做能量选择），右侧是测量伽马的探测器。</p><div class="pgc-img" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><img src="https://p1-tt.byteimg.com/origin/pgc-image/97771bcf52ef4c39a93a9fcf052a5d1f" img_width="589" img_height="332" alt="国内的暗物质探测：中国锦屏地下实验室的未来发展" inline="0" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; border-style: none; max-width: 100%; display: block; margin: 10px auto;"><p class="pgc-img-caption" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; text-align: center; font-size: 12px; color: rgb(119, 119, 119); line-height: 16px;">图5.3.7 CJPL-Ⅱ中JUNA 部分设备安排示意图</p></div><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><strong style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; font-weight: 700;">3. PANDAX-Ⅱ</strong></p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">PANDAX 第三阶段计划为研究双β 衰变建造200kg~1t 气体氙时间投影室，第四阶段计划为暗物质探测与研究建造20t 液体氙时间投影室。以上实验都规划CJPL-Ⅱ中进行。图5.3.8 所示为这两个实验在CJPL-Ⅱ中的布局。</p><div class="pgc-img" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><img src="https://p1-tt.byteimg.com/origin/pgc-image/cd6ba574d194413794c285f5de12f085" img_width="581" img_height="215" alt="国内的暗物质探测：中国锦屏地下实验室的未来发展" inline="0" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; border-style: none; max-width: 100%; display: block; margin: 10px auto;"><p class="pgc-img-caption" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; text-align: center; font-size: 12px; color: rgb(119, 119, 119); line-height: 16px;">图5.3.8 PANDAX-Ⅱ未来实验在CJPL-Ⅱ中的布局</p></div><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><strong style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; font-weight: 700;">4. 太阳中微子实验</strong></p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">我们已经知道太阳内的核聚变反应不仅产生光和热，还发射出大量中微子。多年来对太阳中微子的测量与研究，让我们不仅知道了太阳内部是如何反应的，还确立了标准太阳模型，同时证实了三种中微子之间的相互转换（或称中微子振荡）。</p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">近期Borexino 实验成功地辨别出太阳内三种核反应产生的中微子（这三种反应中微子分别用7Be、pep 和 pp来表示），并测量出各自的通量。如果考虑到中微子到达地球过程中的中微子振荡效应，实验与标准太阳模型的预言符合得很好。但到目前为止还没有直接测量到碳氮氧（CNO）三元素在太阳内循环反应过程中产生的中微子。要知道，碳氮氧的循环反应不仅是太阳内主要的高温过程，也是高温恒星演化过程中的主要能量释放过程，所以测量CNO中微子具有非常重要的科学意义。清华大学的科学家为此提出建议：在CJPL-Ⅱ开展CNO 中微子测量。实验预计采用2 千吨的液体闪烁体或水基闪烁体探测器，图5.3.9 所示为探测器示意图。</p><div class="pgc-img" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><img src="https://p1-tt.byteimg.com/origin/pgc-image/1108ff59a3f244e18298af230081aa79" img_width="334" img_height="338" alt="国内的暗物质探测：中国锦屏地下实验室的未来发展" inline="0" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; border-style: none; max-width: 100%; display: block; margin: 10px auto;"><p class="pgc-img-caption" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; text-align: center; font-size: 12px; color: rgb(119, 119, 119); line-height: 16px;"></p></div><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><strong style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; font-weight: 700;">将液体闪烁体或水基</strong></p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">闪烁体装在直径12m、高12m 的圆柱形不锈钢罐内，罐内周围有大量光电倍增管。太阳中微子进入探测器内与闪烁体发生散射，散射出电子再激发闪烁体发出荧光。荧光被探测器内四周的光电倍增管接收后被转换成电信号。图5.3.10 所示为探测器在地下实验室CJPL-Ⅱ内的安排，两个圆柱形探测器可安放在实验室两端。预期中对5 年的数据进行采集，希望不但可以发现CNO 中微子，而且提高对太阳中三种重要反应（7Be、pep 和pp）中微子通量的测量精度。</p><div class="pgc-img" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><img src="https://p1-tt.byteimg.com/origin/pgc-image/28a6f70d27604f90994c1955c0a9e881" img_width="409" img_height="315" alt="国内的暗物质探测：中国锦屏地下实验室的未来发展" inline="0" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; border-style: none; max-width: 100%; display: block; margin: 10px auto;"><p class="pgc-img-caption" style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 0px; padding: 0px; text-align: center; font-size: 12px; color: rgb(119, 119, 119); line-height: 16px;">图5.3.10 太阳中微子探测器在CJPL-Ⅱ地下实验室内的安排</p></div><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);"><strong style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; font-weight: 700;">小结</strong></p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">位于我国四川凉山自治州的中国锦屏地下实验室是目前世界暗物质研究领域中最深的地下实验室，岩石覆盖2400m，具有良好的地理位置和工作条件、优越的物理实验环境和极低的宇宙线强度，受到国内外科学界的极大关注。</p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">我国的两个暗物质实验CDEX 和PANDAX，在CJPL 成功运行并取得了世界领先的研究成果，极大地推动了我国暗物质探寻的基础前沿研究，使我国的暗物质直接探测实验在短短几年内进入国际暗物质研究的前列。</p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">中国锦屏地下实验室一期（CJPL-I）的总容积仅仅4000m3，远不能满足国内外极深地下实验的空间要求。为满足国内外学界的热烈期望，清华大学和雅砻江流域水电开发有限公司共同决定建设具有更大空间的中国锦屏地下实验室二期（CJPL-Ⅱ）。CJPL-Ⅱ项目规划建设总容积约13 万m3，由洞径为14m×14m，长约65m 的8 个通用型实验空间组成，2016 年已初步建成。目前已经有多个实验项目计划在CJPL-Ⅱ实施。</p><p style="-webkit-tap-highlight-color: transparent; box-sizing: border-box; margin: 16px 0px; padding: 0px; color: rgb(34, 34, 34); font-family: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', 'Helvetica Neue', Arial, sans-serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: 28px; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);">CJPL-Ⅱ必将成为国际上岩石覆盖最深，空间最大，也是条件最好的地下实验室，必将成为我国优良的深地实验平台和辐射本底极低实验领域的新基地，全面促进我国相关领域的研究，也一定会成为国际暗物质及其相关领域研究的开放性地下实验室。</p>
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