Activation and early life of a pressed barium scandate cathode

Oostrom, A. van; Augustus, L.

doi:10.1016/0378-5963(79)90033-3

Cited by 64 publications

(22 citation statements)

References 7 publications

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“…It can be clearly seen that Sc distributes on all surface of framework grains and coincides perfectly with Ba though the latter exhibits a more even distribution. In contrast to the cases of pressed scandate cathode which contains obvious scandium-rich areas [12] or thin film top-layer scandate cathode in which the Sc-containing layer covers non-uniform pores and tungsten areas of cathode underneath [13], a very uniform distribution of Sc and Ba on W substrate has been realized in our work. Fig.…”

Section: Characterization Of Re-sc 2 O 3 -W Matrix Dispenser Cathodementioning

confidence: 69%

Emission property of scandia and Re doped tungsten matrix dispenser cathode

Wang

et al. 2008

Journal of Alloys and Compounds

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Section: Characterization Of Re-sc 2 O 3 -W Matrix Dispenser Cathodementioning

confidence: 69%

Emission property of scandia and Re doped tungsten matrix dispenser cathode

Wang

et al. 2008

Journal of Alloys and Compounds

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“…Table 1 lists the development of the emission capacity of different types of scandate cathodes. Dating back to 1979, Figner et al [22] and van Oostrom et al [11] prepared the pressed scandate cathode and obtained a zero-field current density of 10 A cm −2 at 950 °C b , while a higher emission of 20 A cm −2 was achieved by the impregnated scandate cathode invented by van Stratum et al [23], in which scandia was added to the impregnant. Obviously, the traditional impregnated scandate cathode has a better emission performance than the pressed one.…”

Section: First-generation Scandate Cathodementioning

confidence: 99%

“…A large number of studies showed that based on the current widely used Ba-W cathode, the addition of a certain amount of scandia can significantly improve the emission performance. Therefore, the scandate cathode is considered as one of the main candidates for the next generation high current density cathodes [4][5][6][7][8][9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

A review on scandia doped tungsten matrix scandate cathode

et al. 2019

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As the cathode with the highest electron emission capability in the thermionic cathode, the scandate cathode has attracted more and more attention in recent years, especially the scandia doped tungsten matrix scandate cathode. Experimental studies show that scandia doped tungsten matrix scandate cathodes with submicron microstructures exhibit excellent emission capacity, and the pulse emission current density in the space-charge region can be over 35 A cm −2 at 850 °C b. In the direct current (DC) condition with temperature compensation, the emission current density could reach 25 A cm −2 at 850 °C b. The device lifetime is over 3700 h after operating at 950 °C b with the DC loading of 40 A cm −2. The emission mechanism of the scandate cathode including the effect of the surface structure and composition on the work function of the cathode are systematically reviewed.

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“…One of the views is that this effect is caused by the uneven work function at the surface of the scandium-containing cathodes. When the cathode is in the transition zone, some areas of the cathode surface enter the temperature limited zone, but other parts remain in the space charge limited zone [11,29]. From the perspective of a semiconductor model, another viewpoint is that the increase of emission is due to a decrease of the work function in the semiconductor layer caused by external field penetration.…”

Section: Analysis Of High Emission Characteristics Of Scandate Cathodmentioning

confidence: 99%

Study on Low-Temperature Emission Performance of Scandate Cathode with Micro-Blade-Type Arrays

Yin

Zhang

et al. 2019

Materials

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In order to meet the requirements of high-frequency vacuum electronic devices with small size, high current density, and low working temperature, a kind of porous tungsten scandate cathode with micro-blade-type arrays was developed. The micro-blade-type arrays were fabricated by laser engraving technology. Subsequently, the cathode was prepared by a vacuum copper removal process and impregnated with active substances at high temperature. Experimental results show that the cathode exhibits excellent low-temperature electron emission performance and that the maximum pulse electron emission current density reaches 81.18 A/cm2 at 800 °C. The cathode also shows apparent combined thermal-field emission characteristics. Further analysis shows that a high electric field strength plays an important role in the electron emission of the scandate cathode. By virtue of the electric field enhancement effect formed by the fabricated micro-blade-type arrays on the cathode surface, the prepared cathode achieves high electron emission capacity.

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Activation and early life of a pressed barium scandate cathode

Cited by 64 publications

References 7 publications

Emission property of scandia and Re doped tungsten matrix dispenser cathode

Emission property of scandia and Re doped tungsten matrix dispenser cathode

A review on scandia doped tungsten matrix scandate cathode

Study on Low-Temperature Emission Performance of Scandate Cathode with Micro-Blade-Type Arrays

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