The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform

C A N Conde - One of the best experts on this subject based on the ideXlab platform.

  • monte carlo simulation study of the characteristics of xe ne gas mixtures as detection media in gas proportional ionization counters
    IEEE Transactions on Nuclear Science, 2007
    Co-Authors: F P Santos, P J B M Rachinhas, T H V T Dias, A D Stauffer, F I G M Borges, C A N Conde
    Abstract:

    A Monte Carlo simulation has been developed to investigate the performance of Xe-Ne filled proportional ionization counters, with a special interest on the intrinsic energy resolution Rint as a function of the Xe-Ne mixtures composition. The Monte Carlo simulation reproduces the growth of single-electron-initiated avalanches in cylindrical geometry, and the results for Rint are discussed in terms of the influence of the Penning ionization on the statistical parameter f characterizing the fluctuations of single-electron avalanches gain. The results for Rint, and f, as well as for the multiplication factor M, are calculated for each mixture as a function of the reduced Anode Voltage K=V/ln(c/a), where V is the Voltage applied to the Anode-wire and c/a is the cathode-to-Anode radius ratio

  • Monte Carlo simulation study of the characteristics of Xe-Ne gas mixtures as detection media in gas proportional ionization counters
    IEEE Symposium Conference Record Nuclear Science 2004., 2004
    Co-Authors: F P Santos, P J B M Rachinhas, T H V T Dias, A D Stauffer, F I G M Borges, C A N Conde
    Abstract:

    A Monte Carlo simulation has been developed in order to assess the use of Xe-Ne gas mixtures as detection media in gas proportional ionization counters, examining in particular the parameter most relevant for the performance of a detection medium: the intrinsic energy resolution R/sub int/. This parameter, which establishes a theoretical limit to the detection capability of a detector, has been calculated as a function of the mixtures composition. The Monte Carlo simulation code developed fully reproduces the growth of single-electron-initiated avalanches in cylindrical geometry and results for R/sub int/ are discussed in terms of the parameter f, the statistical fluctuations parameter characterizing single-electron-avalanches. This parameter is calculated for each mixture as a function of the reduced Anode Voltage K=V/ln(c/a), where V is the Voltage applied to the Anode-wire and c/a is the cathode-to-Anode radius ratio. Results for the gas multiplication factor M, characterizing each mixture composition at a given applied electric field, were also obtained.

  • monte carlo simulation of xenon filled cylindrical proportional counters
    Nuclear Science Symposium and Medical Imaging Conference, 1994
    Co-Authors: P J B M Rachinhas, T H V T Dias, F P Santos, A D Stauffer, C A N Conde
    Abstract:

    Single electron avalanche processes in a xenon filled cylindrical proportional counter have been simulated using a detailed Monte Carlo technique. The avalanche gain A and its average value M as well as its frequency distribution and spread parameter b have been calculated for xenon at atmospheric pressure, for a 2.55 cm cathode radius and 12.5 and 50 /spl mu/m Anode radii. A discussion is made of the results obtained for M as a function of the Anode Voltage in terms of prevailing theories. It is found that Monte Carlo calculated M values are markedly lower than those obtained analytically using the first Townsend ionization coefficient calculated under a uniform field. This puts into evidence the relevance of the non-equilibrium nature of avalanche processes. >

Jun Chen - One of the best experts on this subject based on the ideXlab platform.

  • integrated zno nano electron emitter with self modulated parasitic tunneling field effect transistor at the surface of the p si zno junction
    Scientific Reports, 2016
    Co-Authors: Tao Cao, Laitang Luo, Yifeng Huang, Juncong She, Shaozhi Deng, Jun Chen
    Abstract:

    The development of high performance nano-electron-emitter arrays with well reliability still proves challenging. Here, we report a featured integrated nano-electron-emitter. The vertically aligned nano-emitter consists of two segments. The top segment is an intrinsically lightly n-type doped ZnO nano-tip, while the bottom segment is a heavily p-type doped Si nano-pillar (denoted as p-Si/ZnO nano-emitter). The Anode Voltage not only extracted the electron emission from the emitter apex but also induced the inter-band electron tunneling at the surface of the p-Si/ZnO nano-junction. The designed p-Si/ZnO emitter is equivalent to a ZnO nano-tip individually ballasted by a p-Si/ZnO diode and a parasitic tunneling field effect transistor (TFET) at the surface of the p-Si/ZnO junction. The parasitic TFET provides a channel for the supply of emitting electron, while the p-Si/ZnO diode is benefit for impeding the current overloading and prevent the emitters from a catastrophic breakdown. Well repeatable and stable field emission current were obtained from the p-Si/ZnO nano-emitters. High performance nano-emitters was developed using diamond-like-carbon coated p-Si/ZnO tip array (500 × 500), i.e., 178 μA (4.48 mA/cm2) at 75.7 MV/m.

Motoo Yumura - One of the best experts on this subject based on the ideXlab platform.

  • super high luminance light source device with carbon nanotube emitter
    Shinku, 2001
    Co-Authors: Junko Yotani, Sashiro Uemura, Takeshi Nagasako, Hiroyuki Kurachi, Hiromu Yamada, Tomotaka Ezaki, Yahachi Saito, Yoshinori Ando, Xinlou Zhao, Motoo Yumura
    Abstract:

    We have developed the light-source device which emits primary color of super-high luminance and fast switching, the device will be used for the light-source of a projector which consists of liquid crystal display (LCD). In order to perform super-high luminance, we must consider that very high Anode Voltage of 30 kV and the emission current of 500-1000 μA will be required. As a result, the improved structure of electrode system, X-ray shield and cooling system were installed in the developed light-source device.In this paper, we proposed the above mentioned device structure, and the cathode of carbon nanotube (CNT) was the most suitable for the electron emitter. A special CNT that is called nanografiber (NGF) was selected among CNT materials, and the cathode demonstrated that high current density was obtained and the enough electron emission was kept for a long time against ion bombardment. A super-high green luminance of 1 ×106 cd/m2 was achieved by this light-source device.

  • 20 3 super high luminance light source device with carbon nanotube emitter
    SID Symposium Digest of Technical Papers, 2001
    Co-Authors: Junko Yotani, Sashiro Uemura, Takeshi Nagasako, Hiroyuki Kurachi, Hiromu Yamada, Tomotaka Ezaki, Yahachi Saito, Yoshinori Ando, Xinluo Zhao, Motoo Yumura
    Abstract:

    Carbon nanotubes (CNTs) have been attracting considerable attention as field emitters. An excellent performance of carbon-nanotubes as field-emitters was demonstrated using a high-Voltage FED element at Society for Information Display (SID) in 1998 where a lighting element for outdoor large size display and a flat panel were presented with the screen printed nanotube cathode. After that, we reported experimental results of a light source tube which was able to be emitted luminous flux of more than 1000lm in prospect at International Display Workshops'00 (IDW'00). In this paper, we described a light-source device which performed super-high luminance with special multi-walled nanotubes (MWNTs) called nanografiber (NGF) as field emitters. The electrodes passed through electrons was improved for more uniform landing to the phosphor screen. X-ray shield and cooling for phosphor screen were investigated for a practical use and life-time confirmation. The device was experimentally applied to one of projection displays with liquid crystal display (LCD) as light sources. NGF cathodes have been tested under dc driving condition with high current and high Anode Voltage(25–30kV) against high Voltage ion bombardment. The degradation of phosphors has been tested to maintain super-high luminance under high density electron irradiation and efficient cooling.

Xiao Wei Sun - One of the best experts on this subject based on the ideXlab platform.

  • high efficiency surface conducted field emission from a zno nanotetrapod and mgo nanoparticle composite emitter
    Applied Physics Letters, 2008
    Co-Authors: Kai Hou, Xiaxi Yang, Jin Zhang, Wei Lei, Xiaobing Zhang, Baoping Wang, Xiao Wei Sun
    Abstract:

    We report a surface-conducted field emitter made of a ZnO nanotetrapod and MgO nanoparticle composites with a high emission efficiency (∼100%) and current (3.77 mA at a gate Voltage of 100 V and Anode Voltage of 1800 V). The fabrications of the triode structure with a 10×10pixel array and corresponding driving method have been proposed. The electron trajectories are simulated according to the structure. Individual pixel addressing can be achieved by a sequential scanning mode. Display of moving images employing this triode structure was demonstrated. The results are of significance to the development of ZnO based triode field emitters.

Zhixian Lin - One of the best experts on this subject based on the ideXlab platform.

  • surface conducted field emission electron sources with zno emitters of different morphologies
    Journal of Alloys and Compounds, 2016
    Co-Authors: Yongfan Zhang, T Jin, Tailiang Guo, X T Zhou, Zhixian Lin
    Abstract:

    Abstract Surface-conducted field emission electron sources using ZnO nanostructures as surface-conducted emitters have been successfully fabricated, where the linear cathode and gate electrodes were interdigitated and paralleled on the same plane and ZnO emitters with different morphologies were deposited in the gap between the cathode and gate electrode. Field emission investigations indicate that the turn-on Voltage of the fabricated SCFE electron sources with ZnO nanorods, ZnO nanotubes, and ZnO nanocones modifies from 260 V to 220 V at the Anode Voltage of 2 kV. The emission efficiency of SCFE electron source with ZnO nanocones is as large as 43.6%, which is much higher than that of SCFE electron sources with ZnO nanorods and nanotubes at the gate Voltage of ∼300 V. The whole surface emission of the fabricated electron source with ZnO nanocones on the fluorescent screen is more homogeneous than that of the electron sources with ZnO nanorods and nanotubes.