応用物理
Online ISSN : 2188-2290
Print ISSN : 0369-8009
ISSN-L : 0369-8009
30 巻 , 5 号
選択された号の論文の13件中1~13を表示しています
  • 納賀 勤一
    1961 年 30 巻 5 号 p. 297-308
    発行日: 1961/05/10
    公開日: 2009/02/09
    ジャーナル フリー
  • 鴫原 文七
    1961 年 30 巻 5 号 p. 309-314
    発行日: 1961/05/10
    公開日: 2009/02/09
    ジャーナル フリー
    The usual characteristic equation concerning MgO cold cathode derived from simple electron avalanche mechanism is insufficient to explain many experimental results.
    A new characteristic equation is derived by taking into consideration the effects of space charge in MgO layer and conductivity etc. as follows;
    i=i0 exp [(V0-Fsd){(A-BFs)-Bi/σ}]
    where i=total current
    i0=initiating current
    V0=applied voltage
    Fs=threshold field strength
    σ=conductivity of MgO layer
    d=thickness of MgO layer
    A, B=constant
    This equation verifies many experimental results that have remained unexplained.
  • 森田 吾夫, 山下 英男
    1961 年 30 巻 5 号 p. 314-320
    発行日: 1961/05/10
    公開日: 2009/02/09
    ジャーナル フリー
    Properties of magnesium oxide cold cathode electronic tube developed by U. S. Army and Tung-Sol electric researchers are studied. After preliminary examination on material, production process and starting method of the cathode, self-sustained emission, triode characteristics, noise, and life of the tube are investigated.
    The cathode temperature was found to increase when the cathode current density is raised. At small current density, the current varies exponentially with voltage. The noise current was found very large, flicker noise predominating. Life test on diode of the early stage showed that at the cathode current density of 7.6 mA/cm the life is shortened.
  • 中村 勝吾
    1961 年 30 巻 5 号 p. 320-326
    発行日: 1961/05/10
    公開日: 2009/02/09
    ジャーナル フリー
    The relation of the change of emission current in starting process or of the transient change of sustained emission of unstable MgO cathode to the initial velocity distribution of electrons is examined by pulsive-retarding field method and cinema-graphic method.
    Prior to MgO cathode emission being started by electron bombardment, the surface potential rises suddenly, and when the noise current, which is formed by the group of low velocity electrons, reaches a certain level, the emission starts suddenly. The self-sustained emission becomes steady after fluctuation of a short duration. The start of the emission seems to be initiated by local discharge on the surface of MgO layer.
    The self-sustained emission comprises three components: the first is of above 10 kilo-cycle and is independent of the velocity distribution; the second is the flicker noise with varying velocity distribution; the third is of accidental nature, arising from ever changing emission surface.
    Method for reducing the fluctuation of emission are discussed.
  • 1961 年 30 巻 5 号 p. 326
    発行日: 1961年
    公開日: 2009/02/09
    ジャーナル フリー
  • 秦 卓也, 岡田 武夫, 青木 伸一
    1961 年 30 巻 5 号 p. 327-331
    発行日: 1961/05/10
    公開日: 2009/02/09
    ジャーナル フリー
    Various kinds of magnesium oxide film cold cathode are made and their pulse current charac-teristics are studied.
    When rectangular voltage is applied to the collector while the sustain current is on, the built-up current increases till the next stable state is reached. In this unstable period, two kinds of time lag are observed: one is the time lag during which the current remains unchanged, the other is the time spent from the start of the current increase to the stable state. The former seems mostly statistical time lag of fluctuous and accidental nature, while the latter is the forma-tive time lag-the accumulation of positive space charge in MgO raises the internal potential and leads to the formation of a new stable potential distribution reminding of the mechanism of charg-ing a condenser through high resistance.
    Amount of the total time lag, which often reaches to several mili sec., depends on how MgO film is prepared. It is important to go into the process of preparation for shortening the time lag.
  • 日比 忠俊, 石川 和雄
    1961 年 30 巻 5 号 p. 332-338
    発行日: 1961/05/10
    公開日: 2009/02/09
    ジャーナル フリー
    With a Muller type electron microscope of ordinary evacuation system, emission patterns of nickel single crystals are observed at high temperature. Crystal faces of nickel are found divided into two groups: one is the group of faces, such as (320) face, emission of which appears in the early stage of activation, monotonously increasing with rising temperature, the other is the group of faces, such as (211) face, emission of which appears after prolonged activation treatment, with a maximum at a certain temperature. In each group, atomic packing of a face is found looser as its work function is smaller. The cause that the crystal faces become divided into two groups is discussed. Lastly, the cathode at a high temperature is quenched to room temperature while the anode voltage is being applied. The result shows that, as the activation progresses, the pattern obtained at room temperature becomes more alike what appears at high temperature and lasts
  • 北川 賢司, 梨本 柳三
    1961 年 30 巻 5 号 p. 338-344
    発行日: 1961/05/10
    公開日: 2009/02/09
    ジャーナル フリー
    High temperature field emission pattern of various nickel sleeve materials used for oxide-coated cathode are observed with a Muller type electron microscope and the effect of reducing impurities in the material, migration effect of magnesium in particular, on the emission is studied.
    The patterns observed on crystal faces of pure Ni and Si-W-Ni are stable but those of Mg-Ni and Mg-W-Ni are found very unstable. This unstableness originates from (010) face with Mg-Ni, from (100) face with Mg-W-Ni, and the more the Mg content, the more the unstableness; it varies also with the face. Migration of Mg seems therefore to have an intimate relation with the unstableness of field emission pattern.
  • 菅田 栄治, 金 鉉佑
    1961 年 30 巻 5 号 p. 345-352
    発行日: 1961/05/10
    公開日: 2009/02/09
    ジャーナル フリー
    Behaviour of thorium atoms on tungsten surface in ultra high vacuum is studied with F. E. M. In aging at the optimum temperature, three radial lines appear on 111 face in the first three minutes. In ten minutes, these three lines transform into a triangle and in thirty minutes into a shape of doughnut which is the pattern signifying the maximum coverage with Th atoms, the work function being φ=2.75±0.15 eV. Even in this condition, 110 and 100 faces remain free from Th atoms, while 111 face has over one layer of adsorbed atoms. The adsorption force is strongest on 111 face and weakest on 211 face. Measurement of activation energy gives 2.9±0.1 eV and 7.45±0.15 eV for surface migration and desorption respectively.
  • 菅田 栄治, 金 鉱佑
    1961 年 30 巻 5 号 p. 353-355
    発行日: 1961/05/10
    公開日: 2009/02/09
    ジャーナル フリー
  • 北川 賢司
    1961 年 30 巻 5 号 p. 356-362
    発行日: 1961/05/10
    公開日: 2009/02/09
    ジャーナル フリー
    Some thoriated tungsten filaments used in vacuum tubes have abnormally high evaporation of emissive matter at initial stage of aging process, which however does not affect the normal emission characteristics, though occasionally faulty grid emission leads to breakdown of the tubes. In order to investigate the cause of such abnormality, experimental tubes with thoriated tungsten filaments in varied conditions are prepared and emission patterns are examined with a Johnson type emission microscope. Of all the filaments tested, only those that had the said abnormality were found to undergo reversal of emission pattern, dark area of the pattern becoming bright in initial stage of aging process. This reversal of pattern occurs readily when the tube vacuum deteriorates. Under optical microscope, those responsible filaments alone show cracks in their carburized surface layer, probably produced either before or during the carburization. The reversal of pattern is therefore explained as related to abnormal evaporation and cracking in carburized surface layer of the filament.
  • 鴫原 文七, 久我 和夫
    1961 年 30 巻 5 号 p. 362-365
    発行日: 1961/05/10
    公開日: 2009/02/09
    ジャーナル フリー
    Behavior of barium component in Ni sintered cathode during the life is studied.
    Evaporation rate of barium component and distribution of barium content in the cathode are measured during the life, and diffusion constant and evaporation constant of barium component are derived. Results showed that Ba evaporation constant of sintered cathode is comparable with that of oxide coated cathode, but Ba diffusion constant of the former is several ten times as large as that of the latter, which proved the special feature of Ni sintered cathode.
  • 立原 芳彦, 秦 卓也, 小板橋 正康
    1961 年 30 巻 5 号 p. 366-371
    発行日: 1961/05/10
    公開日: 2009/02/09
    ジャーナル フリー
    In manufacturing tubes with oxide coated cathode, exhaustion of gas given off by decompssition of coating material BrSr (CO3)2 is one of the processes that influence much the performance of the cathode. During the exhaustion process, we often encounter with insufficient decomposition of the carbonate, sintering of BaO crystals by over-heating, or contamination due to oxidation on the core nickel and other parts in the tube, which are all undesirable. To study the influence of exhaustion process on the cathode performance, a servo pressure controller is used with which the evolution of gas by decomposition from the cathode is kept at a desired rate by automatically controlled input to the cathode. Gas analysis showed that the quicker the decomposition as well as the exhaustion are carried out, the slighter is the contamination on the nickel surface even if the pressure of evolved gas is high. Contamination on core nickel seems to depend upon the duration the core nickel is exposed to evolved gas rather than the gas pressure in the tube.
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