BARREL 3D X-ray Spectrometer (FSPC) Bremsstrahlung X-ray Spectrum Fast Time Resolution, Level 2, 0.05 s Data

FSPC: Six channels of fast time resolution, 50 ms, Bremsstrahlung X-ray spectra detected with a NaI Scintillator. Each channel is separated in its own variable: FSPC1a, FSPC1b, FSPC1c, FSPC2, FSPC3, and FSPC4. The nominal energy range covered by the six channels ranges from 0 MeV to 1.5 MeV.

The BARREL Mission was a multiple-balloon investigation designed to study electron losses from Earth's Radiation Belts. Selected as a NASA Living with a Star Mission of Opportunity, BARREL was designed to augment the Radiation Belt Storm Probes, RBSP, mission by providing measurements of the spatial and temporal variations of electron precipitation from the radiation belts. The RBSP mission has since been renamed the Van Allen Probes mission. Each BARREL balloon carried an X-ray spectrometer to measure the bremsstrahlung X-rays produced by precipitating relativistic electrons as they collide with neutrals in the atmosphere, and a DC magnetometer to measure ULF-timescale variations of the magnetic field. BARREL observations collected near latitudes close to either the antarctic and arctic circles at stratospheric altitudes at about 30 km. The BARREL instrumentation provided the first balloon measurements of relativistic electron precipitation while comprehensive in situ measurements of both plasma waves and energetic particles were available. Also, the BARREL data has been used to characterize the spatial scale of precipitation at relativistic energies.

The initial pair of balloon campaigns that were conducted initially during the Austral summer months of January and February of 2013 and 2014 with launches from two stations located in Antarctica: the British base located at Halley Bay on the Brunt Ice Shelf and the South African SANAE IV base (SANAE stand for South African National Antarctic Expedition) located in Vesleskarvet, Queen Maud Land. For the 2013 and 2014 the balloon campaigns, the launch plan was designed to maintain an array with about five payloads spread across about six hours of magnetic local time, MLT, in the region that magnetically maps to the radiation belts. Thus, the BARREL balloon constellation constituted an evolving and slowly moving array able to study relativistic electron precipitation from the radiation belts.

Later campaigns were undertaken in 2015 and 2016 from the Esrange Space Center located in Kiruna, Sweden. The 2015 and 2016 campaigns were undertaken in coordination with the Van Allen Probes mission, the European Incoherent Scatter Scientific Association, EISCAT, incoherent scatter radar system, and other ground and space based instruments. Seven balloon launches occurred during the August 2015 BARREL campaign. A total of eight flights occurred during August 2016.

Summing over the four BARREL campaigns, over 50 small, approximately 20 kg, stratospheric balloons were successively launched. The website creeated and hosted by A.J. Halford (see Information URL below) reports that: "By the end of the campaigns, there were over 90 researchers coordinating on a daily basis with the BARREL team working on 7 different satellite missions, 1 other balloon mission, and way too many ground based instruments to count." Although the BARREL mission launched only balloons during the years from 2013 to 2016, research using data collected on these flights is ongoing, so stay tuned for updates! All data and analysis software are freely available to the scientific community.

The information listed above in this resource description was compiled by referencing several BARREL related resources including primarily the Millan et al. (2013) Space Science Reviews publication, the BARREL at Dartmouth mission web site, and the website maintained by A.J. Halford.

The current release of all BARREL CDF data products are Version 10 files.

BARREL will make all its scientific data products quickly and publicly available but all users are expected to read and follow the BARREL Data Usage Policy listed below.

BARREL Data Usage Policy

BARREL data products are made freely available to the public and every effort is made to ensure that these products are of the highest quality. However, there may occasionally be issues with either the instruments or data processing that affect the accuracy of data. When possible, a quality flag is included in higher level data products, and known issues are posted in the BARREL data repository. You are also strongly encouraged to follow the guidelines below if you are planning a publication or presentation in which BARREL data are used. This will help you ensure that your science results are valid.

* Users should always use the highest version numbers of data and analysis tools. Browse/quick-look plots are not intended for science analysis or publication and should not be used for those purposes without consent of the principal investigator, PI.
* Users should notify the BARREL PI of the data use and investigation objectives. This will ensure that you are using the data appropriately and have the most recent version of the data or analysis routines. Additionally, if a BARREL team member is already working on a similar or related topic, they may be able to contribute intellectually.
* If BARREL team members are not part of the author list, then users should Credit/Acknowledge the BARREL team as follows: We acknowledge the BARREL team (PI: Robyn Millan) for use of BARREL data.
* Users are also requested to provide the PI with a copy of each manuscript that uses BARREL data upon submission of that manuscript for consideration of publication. On publication, the citation should be transmitted to the PI.

The BARREL PI can be contacted at: [e-mail].

An online copy of the BARREL Data Usage Policy document can be found at: https://barrel.rmillan.host.dartmouth.edu/documents/data.use.policy.pdf.

FSPC：6路高时间分辨率（50毫秒）制动X射线（Bremsstrahlung X-ray）能谱，由NaI闪烁体（NaI Scintillator）探测得到。6个通道分别对应独立变量：FSPC1a、FSPC1b、FSPC1c、FSPC2、FSPC3与FSPC4。该6通道覆盖的标称能量范围为0 MeV至1.5 MeV。

BARREL任务是一项多气球探测计划，旨在研究地球辐射带的电子损失现象。该任务入选NASA「与星共存」（Living with a Star）机遇任务（Mission of Opportunity），旨在通过测量辐射带电子沉降的时空变化，对辐射带风暴探测器（Radiation Belt Storm Probes, RBSP）任务进行补充。RBSP任务后续更名为范艾伦探测器（Van Allen Probes）任务。每颗BARREL气球搭载了一台X射线光谱仪，用于测量相对论性电子在大气中与中性粒子碰撞时产生的制动X射线，以及一台直流磁强计，用于测量磁场的超低频（ULF）时标变化。BARREL的观测数据采集于约30公里的平流层高度、接近南极圈或北极圈的纬度区域附近。BARREL的探测设备首次实现了相对论性电子沉降的气球测量，同时可结合等离子体波与高能粒子的原位综合测量。此外，BARREL数据已被用于表征相对论能区电子沉降的空间尺度。

首批气球探测活动于2013年与2014年的南半球夏季（1月至2月）开展，发射站点位于南极洲的两处基地：布伦特冰架（Brunt Ice Shelf）的哈雷湾（Halley Bay）英国科考站，以及位于毛德皇后地（Queen Maud Land）维斯莱斯卡韦特（Vesleskarvet）的南非SANAE IV基地（SANAE为南非国家南极考察队（South African National Antarctic Expedition）的缩写）。在2013与2014年的探测活动中，发射计划旨在维持一个由约5个有效载荷组成的阵列，该阵列在磁地方时（Magnetic Local Time, MLT）跨度约6小时，覆盖与辐射带磁共轭的区域。因此，BARREL气球星座构成了一个随时间演化且缓慢移动的探测阵列，可用于研究辐射带的相对论性电子沉降现象。

后续的探测活动于2015年与2016年在瑞典基律纳的埃斯兰空间中心（Esrange Space Center）开展。2015与2016年的探测活动与范艾伦探测器任务、欧洲非相干散射科学协会（European Incoherent Scatter Scientific Association, EISCAT）的非相干散射雷达系统，以及其他地基与天基探测设备协同开展。2015年8月的BARREL探测活动共实施了7次气球发射，2016年8月的探测活动则完成了8次飞行任务。

四项BARREL探测活动累计成功发射了超过50颗小型平流层气球，单颗气球质量约20公斤。由A.J.哈尔福德（A.J. Halford）创建并维护的网站（详见下文信息链接）曾报道：「截至探测活动结束，已有超过90名研究人员与BARREL团队每日协同工作，参与7项不同的卫星任务、1项其他气球任务，以及数量难以计数的地基探测设备的相关研究。」尽管BARREL任务仅在2013至2016年间发射气球，但基于这些飞行任务采集数据的研究仍在持续进行，敬请关注后续更新！所有数据与分析软件均向科学界免费开放。

本资源描述中的信息参考了多项与BARREL相关的资源，主要包括Millan等人（2013年）发表于《空间科学评论》（Space Science Reviews）的论文、达特茅斯学院BARREL任务官方网站，以及A.J.哈尔福德维护的相关网站。

当前发布的所有BARREL公共数据格式（Common Data Format, CDF）数据产品均为V10版本文件。

BARREL将快速公开所有科学数据产品，但所有用户需阅读并遵守下文列出的BARREL数据使用政策。

BARREL数据使用政策：
BARREL数据产品面向公众免费开放，团队将尽最大努力确保数据产品的最高质量。但偶尔可能会出现仪器或数据处理问题，影响数据准确性。在可行的情况下，高级别数据产品中会包含质量标记，已知问题会发布在BARREL数据仓库中。若您计划使用BARREL数据进行论文发表或学术汇报，我们强烈建议您遵循以下指南，以确保研究结果的科学性与有效性：
1. 用户应始终使用最高版本的数据与分析工具。浏览/快速预览绘图结果不适用于科学分析或论文发表，未经项目首席研究员（Principal Investigator, PI）许可，不得将其用于此类用途。
2. 用户应告知BARREL项目首席研究员其数据使用计划与研究目标。这可确保您正确使用数据，并获取最新版本的数据或分析程序。此外，若已有BARREL团队成员开展类似或相关研究，他们可能会为您提供学术贡献。
3. 若BARREL团队成员未列入作者名单，用户应按以下方式致谢BARREL团队：「我们感谢BARREL团队（首席研究员：Robyn Millan）提供的BARREL数据。」
4. 用户还需在投稿发表使用BARREL数据的论文时，向项目首席研究员提交该论文的副本。论文发表后，需将引用信息发送给首席研究员。

BARREL项目首席研究员的联系方式为：[e-mail]。
BARREL数据使用政策文档的在线副本可通过以下链接获取：https://barrel.rmillan.host.dartmouth.edu/documents/data.use.policy.pdf。