Absolute calibration of air fluorescence telescopes to detect the highest energy cosmic rays by a compact electron accelerator

对空气荧光望远镜进行绝对校准，通过紧凑型电子加速器探测最高能量宇宙射线

• 批准号: 18204020
• 负责人: SAGAWA Hiroyuki
• 金额: $ 29.2万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-18204020/
• 关键词: cosmic ray; accelerator

The Telescope Array, located in the desert of Utah in USA, observes extensive air showers that extremely high energy cosmic rays generate in air by using air fluorescence telescopes (FD). We proposed a very unique method of end-to-end absolute calibration of telescopes by observing air shower induced by electron beams from a compact electron linear accelerator (TA-LINAC) shot in the air. It has the performance of maximum electron energy of 40 MeV and output power of 6.4 mW. We aimed at measuring the energy of40 MeV within 1% accuracy and the beam current of 160pC/pulse of 1μsec width within 5% accuracy. Tatsunobu Shibata (Researcher) and Daisuke Ikeda (Graduate student) cooperatec with us for this research.We designed TA-LINAC by using beam simulation, and investiaged the method of absolute calibration by using TA-LINAC. We constructed TA-LINAC in High Energy Accelerator Research Organization. It was completed in January, 2008, and we succeeded in accelerating beams. We measured the values of magnetic field of a 90-degree bending electromagnet that determines beam energy. within 1% accuracy. We measured the stability of magnetic field that affects the stability of beam energy. Thus we could measure electron energy of 39.75 MeV approximately within 0.01% accuracy.We measured beam current with an accuracy of 3% by a Faraday cup. During beam operation, we use a core monitor to monitor beam current. We confirmed linear relation between the Faraday cup and the core monitor within an accuracy of 5%. After confirming the performance, we sent TA-LINAC to USA. The construction of the concrete base and the fence of radiation control was performed at the site of TA-LINAC near one of the FD station.

位于美国犹他州沙漠中的望远镜阵列利用空气荧光望远镜（FD）观测到极高能宇宙射线在空气中产生的大面积空气簇射。我们提出了一种非常独特的望远镜端到端绝对校准方法，通过观察由紧凑电子直线加速器（TA-LINAC）在空中发射的电子束引起的空气簇射。它具有最大电子能量40 MeV、输出功率6.4 mW的性能。我们的目标是在 1% 的精度内测量 40 MeV 的能量，并在 5% 的精度内测量 1μsec 宽度的 160pC/脉冲的束流。 Tatsunobu Shibata（研究员）和Daisuke Ikeda（研究生）与我们合作进行这项研究。我们利用光束模拟设计了TA-LINAC，并研究了使用TA-LINAC的绝对校准方法。我们在高能加速器研究组织建造了TA-LINAC。 2008年1月完成，我们成功加速了光束。我们测量了决定光束能量的 90 度弯曲电磁体的磁场值。准确度在 1% 以内。我们测量了影响光束能量稳定性的磁场稳定性。因此，我们可以测量 39.75 MeV 的电子能量，精度约为 0.01%。我们通过法拉第杯测量束流，精度为 3%。在束流操作期间，我们使用核心监视器来监视束流。我们确认了法拉第杯和岩心监测器之间的线性关系，精度在 5% 以内。确认性能后，我们将TA-LINAC发送到美国。混凝土底座和辐射控制围栏的施工是在靠近 FD 站之一的 TA-LINAC 现场进行的。

项目成果

T145 : Development of a compact linear accelerator for calibration of atmospheric fluorescence telescopes

T145：开发用于大气荧光望远镜校准的紧凑型直线加速器

• 发表时间: 2008
• 作者: D. Ikeda;et al.
• 通讯作者: et al.

TA131 : 大気蛍光望遠鏡キャリブレーションのための小型線形加速器の開発

TA131：用于大气荧光望远镜校准的紧凑型直线加速器的开发

• 发表时间: 2007
• 作者: 芝田達伸;その;他
• 通讯作者: 他

Status of Telescope Array

望远镜阵列状态

• 发表时间: 2006
• 期刊: Proc. of KASI-APCTP WS : Origin, Propagation and Interaction of Energetic Particles Daejeon, Korea
• 作者: Y.Giga;K.Inui;A.Mahalov;S.Matsui;松浦周二;谷口健二;H.Sagawa et al.
• 通讯作者: H.Sagawa et al.

The Status of Telescope Array

望远镜阵列现状

• 发表时间: 2006
• 期刊: Proc. of Int. Workshop "The UHE Universe : A Vision for the Next Decade" Roma, Italy
• 作者: Saito ;Hiro ; Saito ;Masao ; Sunada ;Kazuyoshi; Yonekura ;Yoshinori;M.Fukushima et al.
• 通讯作者: M.Fukushima et al.

Status of Telescope Array (TA)

望远镜阵列（TA）状态

• 发表时间: 2006
• 期刊: Proc. of CRHEY-07 ; International Workshop on Cosmic Rays and High Energy Universe. Tokyo, Japan
• 作者: Okamura;H.;Tsuda;A;Yajima;J.;and Fukuyama;H;C. -Y. Kao;岩崎昌子;S.Koike;M.Fukushima et al.
• 通讯作者: M.Fukushima et al.