儀器簡介：晶體中的原子對能量在0~500 eV范圍內的電子有很大的散射截面，因此背散射電子中絕大部分是被表面或近表面的原子散射回來的，這就使低能電子衍射(LEED)成為研究表面結構的一個理想的手段。

Reverse View LEED

Reverse View LEED是世界上*早的商業化LEED裝置。經過十余年的生產研發經驗的積累，Reverse View LEED已經發展成為具有優秀的性能、**的穩定性和豐富的軟件的LEED裝置，而且衍生出了一系列其它LEED型號。

● 電子束能量范圍0 ~ 3500 eV

● 可視角度達102度

● 可選配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)

● 可選Video LEED對LEED圖形進行采集和分析，以及I(V)、I(t)分析

● 可選W-Th燈絲或LaB6燈絲

MCP-LEED (Micro-channel plate control electronics)

MCP-LEED采用了高靈敏度的多通道板設計，專門用于要求極低的一次電子束流的分析中，例如敏感材料、絕緣體等。

● 極低的一次電子束流，0.1 ~ 30 nA

● *多兩級多通道板

● 可視角度達70度

● 極低的噪聲水平和極高的穩定性

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