钠蒸汽中通过四波参量过程产生紫外相干辐射的光谱特性

本文报告在钠蒸汽中,通过四波参量过程在327nm,328nm,330nm及333nm处得到紫外相干辐射及对它们光谱特性的研究结果。其中333nm信号的可调谐范围较宽,是一可能应用的紫外相干光源。 关键词：     

一 种 新 的 倍 压 回 路

理论和实验均表明,快磁压缩等离子体的离子温度,随着等离子体柱的角向电场强度Eθ增加而增加,而Eθ又正比于感生此场强的放电线圈两端的电压.为了提高Eθ,可以采用倍压放电技术,将放电线圈两端的电压倍增.本文提出了一种新的倍压回路.一、倍压回路的基本原理及其短路性能1.基本原理:本回路的基本形式如图1(a)所示.其中Gs为起动开关,Gc为低气压间隙去耦式短路开关,负载为原GBH-1的主场线圈,电感为L1,传输电缆共六根,每根长为15m,分为两组.图1(b)为该倍压回路的等效回路,其中R1为负载线圈的电阻,Rc和Lc分别为短路开关的电阻和电感,R2和L…     

电子回旋共振等离子体特性及其对生长氮化镓晶膜的影响

为了解并优化在电子回旋共振等离子体辅助化学汽相沉积GaN晶膜的工艺研究中的等离子体特性,利用朗缪尔探针及法拉第筒系统地测量了离子密度(N_i)、等离子体势(V_p)、电子温度(T_e)及离子流强(J_i)等多个等离子体参量随微波功率(P_w)及沉膜室气压(p)变化的关系.给出了在P_w＝850W,p＝0.22Pa时,上述等离子体参量的轴向及径向分布.GaN晶膜的生长速率、电学及晶体学性能 关键词：     

真空紫外区Ar的高次离化光谱的研究

本文报道了波长在2000—194?真空紫外区域内Ar的高次离化光谱工作。观察到相当数量的新谱线,并归属了其中64条,还找到六个新能级,即:ArIV 3s²3p²(³P)3d²F_5/2,7/2, ArIV 3s²3p²(¹D)3d²S_1/2, ArV3s²3p3d关键词：     

用于四波混频实验的同心热管炉设计

使用金属蒸汽做四波混频实验时,为满足位相匹配要求,通常混入一定数量的缓冲气体[1].使用普通热管炉可以达到此目的,即控制炉温,使金属蒸汽的分压小于所充的缓冲气体的压强.这样在加热区中可形成金属蒸汽与惰性气体的混合.但此时热管炉工作在非热管工作状态,加热电功率的波动会导致炉温的波动,从而引起金属蒸汽分压以及此区域中缓冲气体分压的相应波动(加热区中金属蒸汽分压与缓冲气体分压之和等于非加热区缓冲气体的压强)[2].实际上,加热电功率总是在一定范围内变化,因而系统中无法保持金属蒸汽分压与缓冲气体分压间的固定比例,这对于要求…     

ELECTRON CYCLOTRON CURRENT START-UP FOR OHMIC DISCHARGE ON CT-6B TOKAMAK

Electron cyclotron current start-up as a scheme to initiate ohmic discharges has been investigated with two circuits of open and shorted primary windings of transformer. The experimental results indicate that we can achieve the saving of equivalent flux and the reduction of starting voltage in the initial phase for the two circuits in fundamental frequency resonance region.     

在电子回旋共振等离子体中的非线性现象

文章介绍了在电子回旋共振等离子体中的两类非线性现象：混沌和鞘．观察到准周期和锁频以及等离子体的基频振荡突变到四次谐波的现象，分析了锁频窗内的周期２分叉，测量了等离子体鞘，研究了二次电子发射对鞘的影响．     

THE ION CURRENT BEHAVIOR IN ECR ARGON PLASMA

The ion current density as a function of various system parameters, such as pressure, magnetic field, and microwave power, has been studied by using Faraday cup. The bistability of plasma was observed and discussed.     

BEHAVIOR OF PLASMA FORMED IN A PAGODA-SHAPED RADIO FREQUENCY PLASMA SOURCE

A large volume, high density, and pagoda-shaped radio frequency (rf) plasma source has been developed for use in large scale plasma processing. The inductively coupled plasma (ICP) is created by a pagoda-shaped 13.65 MHz antenna to improve the plasma uniformity on substrate. Plasma densities and electron temperatures are measured by using a Langmuir probe and their radial and axial profiles are attained. Electron density of >1×10¹¹ cm^-3 on the substrate and uniform to ≦±1.6% over 16 cm diameter can be produced at argon pressure of 6.65×10^-1 Pa and input rf power of 1 kW. ICP etching photoresist in O₂ plasma has been tested and the etching uniformity consists with that of the plasma density on the substrate. A large scale etched sample with the uniformity to ≦±1.1% over 10 cm diameter or to ≦±2.2% over 13 cm diameter has been obtained.