Space charge effects in field emission: Three dimensional theory

نویسنده

  • Kevin L. Jensen
چکیده

Field emitters rely on high gradients on microfabricated structures to enable substantial levels of emitted current, which can in turn act to reduce the field at the emission site of a single emitter. An account of that effect is obtained in the following steps: a model of the emitter geometry based on the point charge model that allows for the determination of the apex radius and field enhancement factor for arbitrarily sharp emitter structures is given, followed by an analytical formula for the calculation of total current from such a structure and then by a model of the effect of emitted current in suppressing the field at the emission site. Predictions of the impact of space charge on the emitted current are made and compared to findings of Barbour et al. Phys. Rev. 92, 45 1953 for sharpened structures with varying work function. A discussion is given of the method to combine single tip three-dimensional results with a study of space charge on field emission in one dimension. doi:10.1063/1.3272688

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Space charge effects in field emission: One dimensional theory

The current associated with field emission is greatly dependent on the electric field at the emitting electrode. This field is a combination of the electric field in vacuum and the space charge created by the current. The latter becomes more important as the current density increases. Here, a study is performed using a modified classical one dimensional 1D Child–Langmuir description that allows...

متن کامل

Study by simulation the influence of temperature on the formation of space charge in the dielectric multilayer Under DC Electric stress

Multidielectric polyethylene is a material that is generally employed as insulation for  the HVDC isolations. In this paper, the influence of temperature on space charge dynamics has been studied, low-density polyethylene (LDPE) and Fluorinated Ethylene Propylene (FEP) sandwiched between two electrodes were subjected to voltage application of 5kV (14.3 kV/mm) for extended duration of time ...

متن کامل

Benefits of the Electromagnetic Actuated Valve Train in Gasoline Engine Application

Engines equipped with camless valve trains will have greater space for performance optimization. In this paper, based on the electromagnetic actuated valve train system, one-dimensional and three-dimensional simulation models on engine thermodynamic cycle and in-cylinder charge motion are established, respectively. With the application of early-intake-valve closing (EIVC) strategy,unthrottled l...

متن کامل

Emittance of a field emission electron source

An analytical formula of the emittance of a field emitter is given. In contrast to thermal and photoemission, such a formula contains complexity due to the multidimensional nature of the source. A formulation of emittance is given for oneand three-dimensional 3D field emitters. The 3D formulation makes use of the point charge model of a unit cell emitter coupled with a trajectory analysis to fo...

متن کامل

Effect of Magnetic Field and a Mode-I Crack 3D-Problem in Micropolar Thermoelastic Cubic Medium Possessing Under Three Theories

A model of the equations of two dimensional problems in a half space, whose surface in free of micropolar thermoelastic medium possesses cubic symmetry as a result of a Mode-I Crack is studied. There acts an initial magnetic field parallel to the plane boundary of the half- space. The crack is subjected to prescribed temperature and stress distribution. The formulation in the context of the Lor...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2010