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Electron Cyclotron Resonance Heating (ECRH) has contributed to the achievement of high performance plasma production, high electron temperature plasmas and sustainment of steady-state plasmas in the Large Helical Device (LHD). Our immediate targets of upgrading the ECRH system are 5 MW several seconds and 1 MW longer than one hour power injection into LHD. The improvement will greatly extend the plasma parameter regime. For that purpose, we have been promoting the development and installation of 77 GHz/1-1.5 MW/several seconds and 0.3 MW/CW gyrotrons in collaboration with University of Tsukuba. The transmission lines are re-examined and improved for high and CW power transmission. In the recent experimental campaign, two 77 GHz gyrotrons were operated. One more gyrotron, which was designed for 1.5 MW/2 s output, was constructed and is tested. We have been promoting to improve total ECRH efficiency for efficient gyrotron-power use and efficient plasma heating, e.g. a new waveguide alignment method and mode-content analysis and the feedback control of the injection polarization. In the last experimental campaign, the 77 GHz gyrotrons were used in combination with the existing 84 GHz range and 168 GHz gyrotrons. Multi-frequency ECRH system is more flexible in plasma heating experiments and diagnostics. A lot of experiments have been performed in relation to high electron temperature plasmas by realization of the core electron-root confinement (CERC), electron cyclotron current drive (ECCD), Electron Bernstein Wave heating, and steady-state plasma sustainment. Some of the experimental results are briefly described. © 2009 American Institute of Physics.

A remote steering antenna was recently developed for electron cyclotron heating and current drive (ECH/ECCD) experiments on the TRIAM-1M tokamak. This is the first application of the remote steering antenna concept for ECH/ECCD experiments, which have conditions relevant to the International Thermonuclear Experimental Reactor (ITER). Fundamental ECH and ECCD experiments were conducted in the ITER frequency from the low field using this antenna system. In addition to the angles near 0°, the launcher was a symmetric direction antenna with an extended steering-angle capability of ±(8°–19°). The output beam from the antenna was a well-defined Gaussian with a proper steering angle. The Gaussian content and the steering-angle accuracy were 0.85 and −0.5°, respectively. The high power tests measured the antenna transmission efficiency at 0.90–0.94. The efficiencies obtained in the low and high power tests were consistent with the calculations using higher-order modes. In order to excite the pure O/X-modes in the oblique injection, two polarizers were used to control the elliptical polarization of the incident beam for the ECCD experiments. The fundamental O/X-mode ECH/ECCD was applied to lower hyrid current drive plasmas at the optimized incident polarization. In the X-mode experiment, at medium density (~1 × 1019 m−3), clear differences in the plasma current and the hard x-ray intensity were observed between the co- and counter-steering injections due to the ECCD effect on the coupling of forward fast electrons.

This paper reports on the results of an experimental investigation into electron cyclotron resonance heating (ECRH) using the fundamental O-mode in the large helical device (LHD). The aim of the experiment is to understand the mechanism of the selective excitation of the O-mode EC wave and, thereby, optimize the performance of the ECRH. The polarization angle and the ellipticity of the electric field of the incident high power millimetre waves were varied in the experiment using a pair of grating polarizers. The responses of the plasma stored energy and electron temperature were measured to evaluate the effects. The optimum values of the polarization angle and the ellipticity for the ECRH were identified experimentally. A simple model of power branching between the O- and X-modes is introduced in order to interpret the observed experimental results. Specific to the ECRH in the LHD configuration, the effect of magnetic shear in the plasma peripheral region is considered.

Measurement of the Electron Cyclotron Emission (ECE) spectrum is one of the most popular electron temperature diagnostics in nuclear fusion plasma research. A 2-dimensional ECE imaging system was developed with an adaptive-array approach. A radio-frequency (RF) heterodyne detection system with Software Defined Radio (SDR) devices and a phased-array receiver antenna was used to measure the phase and amplitude of the ECE wave. The SDR heterodyne system could continuously measure the phase and amplitude with sufficient accuracy and time resolution while the previous digitizer system could only acquire data at specific times. Robust streaming phase measurements for adaptive-arrayed continuous ECE diagnostics were demonstrated using Fast Fourier Transform (FFT) analysis with the SDR system. The emission field pattern was reconstructed using adaptive-array analysis. The reconstructed profiles were discussed using profiles calculated from coherent single-frequency radiation from the phase array antenna.

The phased‐array antenna system for Electron Cyclotron/Bernstein Wave Heating and Current Drive experiments has been developed in the QUEST. The antenna was designed to excite a pure O‐mode wave in the oblique injection for the O‐X‐B mode conversion experiments, and its good performances were confirmed at a low power level. The plasma current (

75歳以上の高齢者大腸癌穿孔例の臨床・病理学的特徴を75歳未満の穿孔例と比較検討した.手術数に占める穿孔率は75歳未満3.0%に対して, 75歳以上では19.4%と高率であった.口側遊離穿孔の頻度は75歳未満では4例中1例 (25.0%) に対し, 75歳以上では6例中3例 (50.0%) であった.穿孔癌の占居部位は75歳未満では下部大腸に集中していたが, 高齢者では大腸に広く分布していた.癌の肉眼型はともに2型が75%以上を占め, 壁深達度は高齢者に浅い傾向をみた.ショック症状は75歳未満50.0%, 75歳以上33.3%であり, 直死4例中3例はショック症状を伴っていた.発症から手術までに24時間以上経過した症例は高齢者で66.6%と高率であったが, 経過時間と直死率に相関はなかった.術前併存疾患と術後合併症は高齢者で高率に発生し, これらの症例は高い直死率を示した.

過去12年間に当科で手術した大腸癌272例のうち, 75歳以上の高齢者大腸癌47例の臨床病理学的特徴について75歳以下 (対照群) と比較検討し, 以下の結論を得た. (1) 最近6年間の高齢者大腸癌の手術率は22.8%と, それ以前の11.0%よりも上昇した (p 0.05), 肉眼型, 腫瘍径, 組織型, 壁深達度, Dukes 分類, リンパ転移率, 脈管浸襲率には対照群と差がなかった. (3) 切除率, 治癒切除率は両群間で差はなかったが, 高齢者の直死率は14.9%と対照群の4.0%より高率であった (P

過去14年間の大腸癌切除266例のうち, sm癌8例 (3.0%), pm癌11例 (4.1%) の臨床病理学的特徴と予後について検討した.占居部位はsm癌7例 (87.5%), pm癌8例 (72.7%) がS以下の大腸にあり, 両癌ともに血便・下血の頻度が50.0%以上を占めた.高分化腺癌はsm癌7例 (87.5%), pm癌7例 (63.6%) であった.sm癌は腫瘍径20mm以下6例 (75.0%), 隆起型5例 (62.5%) であった。pm癌の平均腫瘍径は39mmであった.sm癌では全例v0であったが, 1例 (12.5%) にly2, n2 (+) を認めた.pm癌ではv1 18.2%, v3 9.1%, ly1 27.3%, ly3 18.2%, n1 (+) 18.2%, n2 (+) 9.1%であった.sm癌では浸潤度が増すほどリンパ節転移の可能性があり, sm3はR2の術式が妥当と考えた.

直腸癌治癒切除 (40例) 後の局所再発8例 (20%) の臨床病理学的特徴, 予後などにつき検討した.再発までの平均期間は22カ月で, 部位別の再発率はRs18.8%, Ra20.0%, Rb22.2%であった.3型での再発率が6%と高率で, また局在部位では腫瘍中心部が前壁にある例での再発率が高かった.腫瘍最大径6.0cm以上で46.7%に, 周径2/3周以上で50.0%に再発を認めた (p

In the report, a backward wave oscillator (-100 GHz) was used as a local oscillator. In this work, a fast-switching local oscillator part in lower frequency range was built for higher time resolution. The lower frequency becomes wide-band in millimeter-wave range (-100 GHz) using millimeter multipliers. The local-frequency part plays an important role to determine the frequency switching-time, step-width and total range in the ECE measuremt. The frequency switching of the lower local-frequency part is mainly discussed in this report.

急性虫垂炎症状をもって発症した患者に腹部超音波検査と注腸造影を施行し, 7カ月前に同様の症状発現時に他院で行った注腸造影の所見を踏まえて, 結果的に経過観察がなされた虫垂癌の1例を経験した.症例は50歳, 男性.超音波所見では虫垂は腫大し, 壁は不整で中心部は不均一であった.7カ月前の注腸造影所見では虫垂開口部の一部のみが造影され, その壁は硬化と伸展不良を示し, 虫垂開口部の盲腸粘膜は上方へ圧排されていた.当院での注腸造影では盲腸右側の陰影欠損があり, その壁は硬化, 不整を示していた.以上より, 虫垂癌を疑い計画的にリンパ節郭清を含めた回盲部切除を行った.病理組織所見は虫垂根部を中心とした結腸型の原発性虫垂癌であり, 大腸癌取扱い規約によると, V, 5型, pm, ly (-), v (-), n (-), P0, H0&, M (-), stage Iであった.虫垂癌の臨床病理学的特徴について検討を加えた.

当科において経験した大腸重複癌に対し, とくにその治療成績と予後について臨床病理学的検討を加えた.対象は昭和47年から62年までの大腸癌手術症例374例で, 重複癌は29例 (7.8%) あり, その平均年齢は67.7歳男女比は2 : 1であった.重複癌症例において, 血族に悪性疾患の発生しやすい傾向を認め, 他臓器癌は胃癌が多かったが, 大腸癌の占居部位, 肉眼型にはとくに傾向を認めなかった.進行度をみると, stage III以上が66.7%を占め, 進行した状態の癌が多かった.治療成績は治癒切除例44.3%, 非治癒切除例37.3%, 非切除例18.4%であった.予後は不良で, 大腸癌手術後3年以上生存したのは6例, 5年以上生存したのは2例のみであった.複数の臓器に存在する癌を早期発見することの困難なことが考えられ, 重複癌の存在を念頭においた術前検索ならびに術後の経過観察がますます重要になってきていると思われた.