Development of the polarized target for spin-structure studies of the proton in the FNAL-E906 experiment

我们完成了极化质子靶的操作准备工作，从辐照的氨气到KEK现有设备可以实现的阶段。成功地激发了超导磁体，观察到了聚四氟乙烯中氟和聚乙烯微珠中质子的热平衡信号。我们还在山形大学推进了使用辐照聚乙烯纤维和薄膜的偏振目标材料的开发。用电子束辐照聚乙烯样品制成极化靶材，用电子自旋共振技术精确测量辐照样品的自旋密度。

We completed preparations toward operation of the polarized proton target from irradiated-ammonia to the stage where we can achieve with currently available equipments at KEK. The superconducting magnet was successfully excited, and thermal equilibrium signals of fluorine in the Teflon and proton in the polyethylene beads were observed. We have also advanced development of polarized-target materials with irradiated polyethylene fibers and foils at Yamagata University. The polyethylene samples were irradiated with electron beams to make polarized-target materials, and the spin density of the irradiated samples were measured precisely with the ESR.