仪器简介：晶体中的原子对能量在0~500 eV范围内的电子有很大的散射截面，因此背散射电子中绝大部分是被表面或近表面的原子散射回来的，这就使低能电子衍射(LEED)成为研究表面结构的一个理想的手段。

Reverse View LEED

Reverse View LEED是世界上*早的商业化LEED装置。经过十余年的生产研发经验的积累，Reverse View LEED已经发展成为具有优秀的性能、**的稳定性和丰富的软件的LEED装置，而且衍生出了一系列其它LEED型号。

● 电子束能量范围0 ~ 3500 eV

● 可视角度达102度

● 可选配AES (Auger electron spectroscopy) 功能，能量分辨率好于0.5% FWHM ( Combination LEED and Auger control electronics with integral lock-in amplifier)

● 可选Video LEED对LEED图形进行采集和分析，以及I(V)、I(t)分析

● 可选W-Th灯丝或LaB6灯丝

MCP-LEED (Micro-channel plate control electronics)

MCP-LEED采用了高灵敏度的多通道板设计，专门用于要求极低的一次电子束流的分析中，例如敏感材料、绝缘体等。

● 极低的一次电子束流，0.1 ~ 30 nA

● *多两级多通道板

● 可视角度达70度

● 极低的噪声水平和极高的稳定性

LEED-AUGER OPTICS (Models BDL600IR and BDL800IR)

Glass-Display Fused silica glass coated with indium-tin oxide conductive layer and P31 phosphor ( ZnS:Ag:Cu-green， 525 nm wavelength)

BDL600IR......................... 90 angle of acceptance from sample at a distance of 50 mm

BDL800IR......................... 100 angle of acceptance from sample at a distance of 75 mm

Retarding Field Analyzer Concentric assembly of hemispherical grids

BDL600IR................ Working distance from sample 15 mm

BDL800IR................ Working distance from sample 18 mm

Grid Material.................. Gold coated tungsten wire mesh ( 100 mesh， 81% transparency)

Energy Resolution.......... 0.2% - 0.5% at low modulation volt.

Monitoring： 6” or 8” standard viewport

Linear Motion：Up to 150 mm retraction from sample (100mm standard); linear ball bearing and acme thread with all spring electr. connections

Integral Shutter ： Open and close at any position of the linear motion

Magnetic Shielding ： Mu-metal cylinder with front cover for maximum atteniuation

Assembly ： Extreme-high-vacuum compatibility with stainless steel， high alumina and Au-plated copper alloy materials

Mounting ： 6” (CF100) or 8”( CF150) double sided conflat flange with sample distance 145 mm -500 mm

Bakeability ：Under vacuum， 250 C maximum

INTEGRAL MINIATURE ELECTRON GUN

Beam Energy ： LEED - 5 eV to 750 eV

AES to 3000 eV

Beam Current ：LEED - 2 uA at 100 eV and 0.5 mm beam size

AES - up to 100 uA at 3 keV

Beam Size ：from 1 mm to 250 um - adjusted by wehnelt potential， limited by exchangeable aperture down to 50 um

Electron Source ：Tungsten-2% Thoriated filament standard， single crystal LaB6 filament optional

Energy Spread ：0.45 eV (tunsten-rhenium filament)

Overall Size ： 10 mm lens diameter and 80 mm length