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広域災害被災地における臨時通信システムとして，ドローンを用いた無線リレーネットワークを考える．ドローンの飛行モデルである反発飛行について，どの程度離れた位置を目的地とするかを決める反発率を導入し，反発率を変化させた場合の遅延特性を評価する

Supplemental Material, sj-docx-1-tpx-10.1177_01926233211027474 for Chimeric Mouse With Humanized Liver Is an Appropriate Animal Model to Investigate Mode of Action for Porphyria-Mediated Hepatocytotoxicity by Ayumi Eguchi, Satoki Fukunaga, Keiko Ogata, Masahiko Kushida, Hiroyuki Asano, Samuel M. Cohen and Tokuo Sukata in Toxicologic Pathology

After upgrade of J-PARC Linac in 2014, Low Energy Beam Transport (LEBT) beam commissioning of the J-PARC LINAC has been made for improving H-beam intensity extracted from Linac. Currents of two solenoid coils and steering magnets in LEBT are optimized with extraction and acceleration voltages for static acceleration in ion source (IS) which decides on an initial emittance diagram of H⁻ beam. As a result of LEBT and IS parameter optimization, beam transmission rate of RFQ has been reached up to 96 % in 50 mA H⁻ current operation. Moreover, PIC-MC (Particle-In-Cell Monte-Carlo) simulation model is developed for H⁻ transport in LEBT. Comparison between experimental and numerical results are presented to clarify beam physics from IS exit to RFQ entrance., Proceedings of the 28th Linear Accelerator Conf., LINAC2016, East Lansing, MI, USA

We are constructing a linac for development of accelerator components at J-PARC. This linac consists of a H⁻ ion source, a low energy beam transport (LEBT), an radio frequency quadrupole (RFQ) linac, and a diagnostics bean line. The beam energy is 3 MeV, the beam current is 30 mA, and the duty factor is 0.6%, which corresponds to 0.5 kW. The accelerator itself has a capacity of at least 1 kW. However, the beam power is limited by radiation dose, because there are no radiation shields between the accessible area during the operation. The source and LEBT are same as the J-PARC linac's. The RFQ is a used one in the J-PARC linac, called RFQ I. At first, we are planning to conduct experiments of the laser charge exchange development for the transmutation facility. Then, this linac will be used for the development accelerator components such as beam scrapers, bunch shape monitors, laser profile monitors, and so on. We will be able to install new devices into the actual J-PARC linac after the full testing. The development of H⁻ ion source can be carried out at this system, and also RFQ in the future. In this paper, present status of this 3-MeV linac at J-PARC is presented., Proceedings of the 28th Linear Accelerator Conf., LINAC2016, East Lansing, MI, USA

Japan has often been viewed as an Asian country that possesses a genetically homogenous community. The basis for partitioning the country into prefectures has largely been geographical, although cultural and linguistic differences still exist between some of the districts/prefectures, especially between Okinawa and the mainland prefectures. The Major Histocompatibility Complex (MHC) region has consistently emerged as the most polymorphic region in the human genome, harbouring numerous biologically important variants; nevertheless the presence of population-specific long haplotypes hinders the imputation of SNPs and classical HLA alleles. Here, we examined the extent of genetic variation at the MHC between eight Japanese populations sampled from Okinawa, and six other prefectures located in or close to the mainland of Japan, specifically focusing at the haplotypes observed within each population, and what the impact of any variation has on imputation. Our results indicated that Okinawa was genetically farther to the mainland Japanese than were Gujarati Indians from Tamil Indians, while the mainland Japanese from six prefectures were more homogeneous than between northern and southern Han Chinese. The distribution of haplotypes across Japan was similar, although imputation was most accurate for Okinawa and several mainland prefectures when population-specific panels were used as reference.

For the upgrade of the Japan Proton Accelerator Research Complex (J-PARC) linac beam current, a cesiated RF-driven negative hydrogen ion source was installed in 2014 summer shutdown period, and started to operate on September 29, 2014. The ion source has been successfully operated with a beam current and a duty factor of 33 mA and 1.25\% (0.5 ms and 25 Hz), respectively. The result of recent beam operation showed that the ion source is capable of continuous operation for approximately 1,100 h. The spark rate at the beam extractor was observed to be less than once a day, which is acceptable level for the user operation. Although the antenna failure occurred during the user operation on October 26, 2014, there were no further serious troubles since then. In this conference, we will present the some operation parameters and the beam stability of the RF-driven ion source through the long-term user operation., J-PARCリニアックのビーム電流を増強するために、セシウム添加型高周波負水素イオン源を2014年夏の加速器メンテナンス時にインストールし、同年9月29日より運転を開始した。現在、本イオン源はビーム電流33mA、デューティファクタ1.25\%で稼働している。いままでのところ、連続運転時間は約1100時間を達成している。運転中の高圧部放電頻度は1日に1回以下であり、ユーザ運転には影響のないレベルである。2014年10月にアンテナが破損したが、それ以降は深刻なトラブルは発生していない。本会議では、本イオン源の長時間運転における各種パラメータや安定性について発表する。

A numerical model of plasma transport and electromagnetic field in the J-PARC RF ion source has been developed to understand relation between antenna coil heat loadings and plasma production/transport processes. From the calculation, the local plasma density increase is observed in the region close to the antenna coil. The magnetic field line with absolute magnetic flux density 30-120 Gauss results in the magnetization of electron which leads to high local ionization rate. The results suggest that modification of magnetic configuration can be made to reduce plasma heat flux onto the antenna., J-PARC高周波(RF)イオン源のアンテナコイル熱負荷とプラズマ熱流束の関係を明らかにするため、プラズマ輸送過程と電磁場分布を同時に解析する数値シミュレーションモデルを構築した。シミュレーションから、ロッドフィルターおよびカスプ磁石により、アンテナコイル近傍で、磁束密度の絶対値が30-120Gaussの値を取る領域が生じる。このような磁場中では、イオン源内の電子が磁化されるため、コイル近傍で電子密度増加が起こる。すると、水素分子・原子のイオン化が促進されるため、局在的にプラズマ密度が増加する。このとき、アンテナ電位が負の値を取ると、イオン化で生じた水素の正イオンがアンテナに向かって加速され、アンテナの特定部位に熱負荷が集中する結果が得られた。これより、フィルター、およびカスプ磁石の配置変更により、コイル近傍の磁場構造を改変することで、熱負荷が低減されることが指摘された。

The Japan Proton Accelerator Research Complex (J-PARC) cesiated rf-driven H$^-$ ion source (IS), whose requirements are a peak beam intensity of 60mA within normalized emittances of 1.5 $\pi$mm$\cdot$mrad both horizontally and vertically, a flat top beam duty factor of 1.25\% (500 $\mu$s$ \times$ 25 Hz) and a life-time of longer than 1month, has been successfully operated for about one year. The results of the fine-tuning to minimize the emittances of the J-PARC-IS with plasma chamber \#3, which had the largest emittances with initial settings among four plasma chambers, will be presented in this paper. The rod-filter-filed will be finely tuned by selecting magnets with slightly different field strengths and/or changing gap-lengths. The dependence of the beam-hole-diameter on the emittances will be also presented. The tuning procedure to improve the emittances is one of the most important technologies for the IS of the high-energy and high-intensity accelerator., J-PARCセシウム添加高周波駆動負水素イオン源は、約1年間運転に使用されてきた。このイオン源への要求性能は、水平と垂直両方向エミッタンス1.5$\pi$mm$\cdot$mrad内にピークビーム強度60mA、強度一定のビームデューティ1.25\%(500$\mu$s$\times$25Hz)と1ヶ月以上の寿命である。プラズマ容器\#3を使用したエミッタンスを最小にするための微細調整の結果を報告する。初期設定時のプラズマ容器\#3のエミッタンスは、4つの同型プラズマ容器の中で、最も大きかった。わずかに異なる磁場強度を有する永久磁石の選定や磁石間ギャップ長の調整によるロッドフィルター磁場の微細調整や引き出し電極孔径の違いによるエミッタンスの測定結果を報告する。エミッタンス改善のために調整手順は、高強度高エネルギー加速器用イオン源にとって最も重要な技術の一つである。