BARREL 4E X-ray Spectrometer (SSPC) Bremsstrahlung X-ray Spectrum Slow Time Resolution, Level 2, 32 s Data

SSPC: 256 channels of slow time resolution, 32 s, Bremsstrahlung X-ray spectra detected with a NaI Scintillator. The nominal energy range covered by the 256 channels ranges from 0 MeV to 10 MeV. All channels are combined to a single variable named SSPC.

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.

SSPC：256通道慢时间分辨率数据，时长32秒，采用碘化钠（NaI）闪烁体探测轫致辐射X射线能谱。该256个通道的标称覆盖能量范围为0 MeV至10 MeV，所有通道合并为名为SSPC的单一变量。

BARREL任务是一项多气球探测计划，旨在研究地球辐射带电子的损失过程。该任务入选NASA“恒星与生活”机遇任务，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（RBSP）任务进行补充。RBSP任务后续更名为范艾伦探测器任务。每颗BARREL气球搭载一台X射线光谱仪，用于测量相对论电子与大气中性粒子碰撞时产生的轫致辐射X射线；同时搭载一台直流磁力仪，用于测量磁场的超低频（ULF）时标变化。BARREL的观测站点位于接近南极圈与北极圈的纬度附近，飞行高度约为30公里的平流层。BARREL的探测设备首次实现了相对论电子沉降的气球探测，同时可获取等离子体波与高能粒子的综合原位测量数据。此外，BARREL数据已被用于表征相对论能量下电子沉降的空间尺度。

首批气球探测活动于2013年和2014年的南夏季（1月至2月）开展，发射站点位于南极洲的两处基地：布伦特冰架哈雷湾的英国南极科考站，以及位于毛德皇后地韦莱斯卡尔韦特的南非SANAE IV基地（SANAE为南非国家南极考察队的缩写）。在2013年与2014年的探测计划中，发射方案旨在维持一个由约5个有效载荷组成的阵列，覆盖约6小时的磁地方时（MLT）区域，该区域在磁层映射到辐射带范围。因此，BARREL气球星座构成了一个动态且缓慢移动的探测阵列，可用于研究辐射带相对论电子的沉降过程。

后续的探测计划于2015年和2016年在瑞典基律纳的埃斯兰太空中心开展。2015年与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（EISCAT）非相干散射雷达系统及其他地面与天基仪器协同进行。2015年8月的BARREL探测计划共完成7次气球发射，2016年8月则共计完成8次飞行任务。

综合四次BARREL探测计划，共计成功发射超过50颗重量约20公斤的平流层小型气球。由A.J.哈尔福德创建并维护的网站（详见下文信息链接）曾报道称：“截至探测计划结束，已有超过90名研究人员与BARREL团队每日协同工作，参与7项不同卫星任务、1项其他气球探测计划以及数量众多的地面仪器相关研究。”尽管BARREL任务仅在2013年至2016年间发射气球，但基于这些飞行任务收集的数据的相关研究仍在持续，敬请关注后续更新。所有数据与分析软件均对科学界免费开放。

本资源描述中所列信息参考了多项与BARREL相关的资料，主要包括Millan等人（2013年）发表于《空间科学综述》的论文、达特茅斯学院BARREL任务官网以及A.J.哈尔福德维护的相关网站。

当前所有BARREL CDF数据产品的版本为V10文件。

BARREL将快速公开所有科学数据产品，但所有用户均需阅读并遵守下文所列的BARREL数据使用政策。

BARREL数据使用政策
BARREL数据产品免费向公众开放，团队将尽最大努力确保数据产品的最高质量。但偶尔可能存在仪器或数据处理问题影响数据准确性。在可行情况下，高级别数据产品中将包含质量标识，已知问题将发布在BARREL数据仓库中。若您计划使用BARREL数据进行论文发表或学术展示，我们强烈建议您遵循以下指南，以确保您的科研结果可靠有效：
1. 用户应始终使用最新版本的数据与分析工具。浏览/快速预览绘图不适用于科研分析或论文发表，未经首席研究员（PI）同意，不得将其用于此类用途。
2. 用户应告知BARREL首席研究员其数据使用用途与研究目标。这将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团队成员正在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，则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数据支持。”
4. 用户还需在提交待发表稿件时，向首席研究员提供每一篇使用BARREL数据的手稿副本。论文发表后，需将引用信息发送给首席研究员。

BARREL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。