Secondary electron yield measurements from materials with application to collectors of high-power microwave devices

Zameroski, Nathan D.; Kumar, Prashanth; Watts, Christopher; Svimonishvili, Tengiz; Gilmore, M.; Schamiloglu, E.; Gaudet, J.

doi:10.1109/tps.2006.875778

Cited by 13 publications

(6 citation statements)

References 13 publications

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“…The astonishingly low value of d max for as-received is only due to the surface topography induced by the laser processing. The XPS chemical analysis of the Cu surface showed almost the same surface chemistry for both samples, as shown in Table II 36 The electron conditioning, in the range of applied primary electron energy from 80 to 1000 eV, also leads to the SEY decrease for all samples, see Figs. 3-5.…”

mentioning

confidence: 57%

Low secondary electron yield engineered surface for electron cloud mitigation

Valizadeh

Malyshev

Wang

et al. 2014

Applied Physics Letters

112

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Secondary electron yield (SEY or δ) limits the performance of a number of devices. Particularly, in high-energy charged particle accelerators, the beam-induced electron multipacting is one of the main sources of electron cloud (e-cloud) build up on the beam path; in radio frequency wave guides, the electron multipacting limits their lifetime and causes power loss; and in detectors, the secondary electrons define the signal background and reduce the sensitivity. The best solution would be a material with a low SEY coating and for many applications δ < 1 would be sufficient. We report on an alternative surface preparation to the ones that are currently advocated. Three commonly used materials in accelerator vacuum chambers (stainless steel, copper, and aluminium) were laser processed to create a highly regular surface topography. It is shown that this treatment reduces the SEY of the copper, aluminium, and stainless steel from δmax of 1.90, 2.55, and 2.25 to 1.12, 1.45, and 1.12, respectively. The δmax further reduced to 0.76–0.78 for all three treated metals after bombardment with 500 eV electrons to a dose between 3.5 × 10−3 and 2.0 × 10−2 C·mm−2.

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mentioning

confidence: 57%

Low secondary electron yield engineered surface for electron cloud mitigation

Valizadeh

Malyshev

Wang

et al. 2014

Applied Physics Letters

112

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“…ratio of the number of electrons emitted from the material to the number of incident electrons) with incident energy [4,8,[10][11][12][13][14][15][16] and angle [10,11] with respect to the surface, as well as semi-empirical equations for the energy, angular, and spatial distribution [10] of the emitted secondary electrons. Measurements were made by exposing a sample of the material to a monoenergetic electron beam of known current I PE and measuring (i) the sample current I S [17,18] or (ii) the current on a collecting electrode surrounding the sample I C [16,19]…”

Section: Introductionmentioning

confidence: 99%

Analysis of secondary electron emission for conducting materials using 4-grid LEED/AES optics

Patino¹,

Raitses²,

Koel³

et al. 2015

J. Phys. D: Appl. Phys.

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A facility utilizing 4-grid optics for LEED/AES (low energy electron diffraction/Auger electron spectroscopy) was developed to measure the total secondary electron yield and secondary electron energy distribution function for conducting materials. The facility and experimental procedure were validated with measurements of 50-500 eV primary electrons impacting graphite. The total yield was calculated from measurements of the secondary electron current (i) from the sample and (ii) from the collection assembly, by biasing each surface. Secondary electron yield results from both methods agreed well with each other and were within the spread of previous results for the total yield from graphite. Additionally, measurements of the energy distribution function of secondary electrons from graphite are provided for a wider range of incident electron energies. These results can be used in modeling plasma-wall interactions in plasmas bounded by graphite walls, such as are found in plasma thrusters, and divertors and limiters of magnetic fusion devices.

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“…114 This has motivated reexaminations of the phenomenon of secondary electron emission. 115 One key finding of this recent work is that the secondary electron yield is time-dependent, with an evolution time scale of minutes to hours during continuous beam bombardment. The evidence strongly implicates the role of mere monolayer films of gaseous or hydrocarbon adsorbates, consistent with findings reported elsewhere.…”

Section: Dense Beam Impact Physicsmentioning

confidence: 94%

Plasma physics and related challenges of millimeter-wave-to-terahertz and high power microwave generation

2008

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Homeland security and military defense technology considerations have stimulated intense interest in mobile, high power sources of millimeter-wave (mmw) to terahertz (THz) regime electromagnetic radiation, from 0.1 to 10THz. While vacuum electronic sources are a natural choice for high power, the challenges have yet to be completely met for applications including noninvasive sensing of concealed weapons and dangerous agents, high-data-rate communications, high resolution radar, next generation acceleration drivers, and analysis of fluids and condensed matter. The compact size requirements for many of these high frequency sources require miniscule, microfabricated slow wave circuits. This necessitates electron beams with tiny transverse dimensions and potentially very high current densities for adequate gain. Thus, an emerging family of microfabricated, vacuum electronic devices share many of the same plasma physics challenges that are currently confronting “classic” high power microwave (HPM) generators including long-life bright electron beam sources, intense beam transport, parasitic mode excitation, energetic electron interaction with surfaces, and rf air breakdown at output windows. The contemporary plasma physics and other related issues of compact, high power mmw-to-THz sources are compared and contrasted to those of HPM generation, and future research challenges and opportunities are discussed.

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Secondary electron yield measurements from materials with application to collectors of high-power microwave devices

Cited by 13 publications

References 13 publications

Low secondary electron yield engineered surface for electron cloud mitigation

Low secondary electron yield engineered surface for electron cloud mitigation

Analysis of secondary electron emission for conducting materials using 4-grid LEED/AES optics

Plasma physics and related challenges of millimeter-wave-to-terahertz and high power microwave generation

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