BARREL 2K 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：采用碘化钠闪烁体（NaI Scintillator）探测得到的快时间分辨率（50毫秒）轫致辐射X射线能谱，共6个通道。每个通道对应独立变量：FSPC1a、FSPC1b、FSPC1c、FSPC2、FSPC3与FSPC4。六个通道的标称覆盖能量范围为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（Earth's Radiation Belts）的电子损失现象。该任务被选为NASA "与星共存"（Living with a Star）机遇任务，旨在通过探测辐射带内电子沉降的时空变化，对辐射带风暴探测器（Radiation Belt Storm Probes, RBSP）计划进行补充。此后RBSP任务更名为范艾伦探测器（Van Allen Probes）任务。每台BARREL气球载荷均搭载X射线光谱仪，用于测量相对论性电子沉降至大气层并与中性粒子碰撞时产生的轫致辐射X射线；同时搭载直流磁强计，用于探测磁场的超低频（ULF）时标变化。BARREL的观测站位位于平流层约30公里高度，纬度接近南极圈与北极圈区域。BARREL探测设备首次实现了气球平台上的相对论性电子沉降测量，彼时可同步获取等离子体波与高能粒子的全面原位探测数据。此外，BARREL数据还被用于表征相对论能区电子沉降的空间尺度。

首批BARREL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两处：布伦特冰架哈雷湾的英国科考站，以及毛德皇后地维斯莱斯卡韦特的南非SANAE IV站（SANAE为南非国家南极考察队（South African National Antarctic Expedition）的缩写）。2013与2014年的气球探测计划旨在构建一组载荷阵列，使约5台探测载荷在磁地方时（Magnetic Local Time, MLT）跨度约6小时的辐射带磁映射区域内分布。由此，BARREL气球星座形成了一套动态缓慢移动的探测阵列，可用于研究辐射带内的相对论性电子沉降现象。

后续探测活动于2015年与2016年在瑞典基律纳的埃斯兰航天中心（Esrange Space Center）开展。2015与2016年的探测计划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，以及其他地面与天基探测设备协同进行。2015年8月的BARREL探测活动共完成7次气球发射，2016年8月则完成总计8次飞行任务。

综合四项BARREL探测活动，团队先后发射了超过50台重量约20千克的小型平流层气球。由A.J.哈尔福德创建并维护的网站（详见下文信息链接）显示：截至探测活动结束，已有超过90名研究人员每日与BARREL团队协同工作，参与7项不同卫星任务、1项其他气球任务以及数量难以统计的地面探测设备的相关研究。尽管BARREL任务仅在2013至2016年间开展气球探测，但基于本次飞行任务采集数据的相关研究仍在持续，敬请期待后续进展！所有数据与分析软件均向科学界免费开放。

本资源描述中列出的信息，参考了多项与BARREL相关的资料进行编译，主要来源包括Millan等人2013年发表于《空间科学综述》（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 CDF数据产品均为V10版本文件。

BARREL将所有科学数据产品快速公开，但所有使用者均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数据产品向公众免费开放，团队将尽一切努力确保数据产品具备最高质量。但仪器或数据处理过程中偶尔可能出现影响数据准确性的问题。若条件允许，高级别数据产品中会包含质量标识，已知问题也会发布在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，强烈建议遵循以下指南，以确保研究结果的科学性与有效性：
* 使用者应始终使用最高版本的数据与分析工具。浏览/快速预览绘图不应用于科学分析或论文发表，若未经项目首席研究员（Principal Investigator, PI）许可，不得将其用于此类用途。
* 使用者应向BARREL首席研究员告知数据使用用途与研究目标。此举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BARREL团队成员已开展类似或相关主题的研究，他们或可提供学术贡献。
* 若BARREL团队成员未列入作者名单，使用者应按如下方式致谢BARREL团队：本研究感谢BARREL团队（首席研究员：Robyn Millan）提供的BARREL数据。
* 使用者还需在提交论文供审稿时，向首席研究员提供每一篇使用BARREL数据的论文副本。论文发表后，需将引用信息发送至首席研究员。

BARREL首席研究员联系方式：[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。