冉紹爾湯森效應(yīng)試驗報告劉志歡B5合作者宋耀華【引言】著電子的能量的降低而快速減小。在經(jīng)典理論中,散射截面與電子的運動速度無滿足的解釋?！驹囼灷碚摷安襟E】1.了解電子碰撞管的設(shè)計原則，把握電子與原子的碰撞規(guī)章和測量的原子散射截面的方法。測量低能電子與氣體原子的散射幾率Ps與電子速度的關(guān)系。Q小時的電子能量。驗證冉紹爾-湯森效應(yīng)，并學(xué)習(xí)用量子力學(xué)理論加以解釋。二、試驗原理1、理論原理冉紹爾在爭論極低能量電子〔0.75eV—1.1eV〕Q10eV個極大值，而后開頭下降，當(dāng)電子能量漸漸減小到1eVQ1eV1eVQQ=F〔V加速電壓值〕具有一樣的外形，稱為冉紹爾曲線。圖1Xe，氪Ke，氬a0Q度用總散射截面來表示。2、測量原理1逸出，設(shè)陰極電流為IK，電子在加速電壓的作用下，有一局部電子在到達(dá)柵極P恒速運動，受到氣體原子散射的電子則到達(dá)屏極，形成散射電流IS2；而未受到P，IP碰撞管，低溫容器,示波器極電源“Ef”至“2V”“Ec”先調(diào)整至“0V”。示波器觸發(fā)源選“外接”，觸發(fā)耦合選擇“AC”，CH1，CH2“CH1“AC”CH2“AC”“W1”“W2”xIpIs1/2SP板電流的變化。2、直流測量依據(jù)圖2所示的儀器連接圖連接電路，翻開微電流計，調(diào)整微“0.000”〔留意此時應(yīng)當(dāng)將FEf“2.000V”,EaEc“0.000V”。調(diào)整直流加速電壓Ea旋鈕，等到微電流計主機上兩個表頭示值全部為“0.000”時，把碰撞管下部約1/2浸入液氮，調(diào)整Ea旋鈕觀看微電流計兩個表頭是否同時Ec〔留意此時保證電1/2到達(dá)上述要求?！?V0.1V2V-3V0.2V0.5VEfEa=1V1VIpIs【試驗結(jié)果】直流測量試驗數(shù)據(jù)室溫下燈絲電壓Ef=2.27V，液氮溫度下燈絲電壓Ef=2.00V，補償電壓Ec=1.11V，初始加速電壓Ea0=-0.13VEa/VIp*/uAIs*/uAIp/uAIs/uA√(Ea-Ea0)PsQL-0.130.0000.000.0000.000.000-0.030.0010.030.0030.050.316-0.8000.0890.089-0.5880.030.0030.120.0040.160.4000.0000.0000.130.0150.320.0120.430.5100.4050.5190.230.0530.860.0351.150.6000.5060.7060.330.1392.032.382.380.730.730.6780.4540.6050.430.2984.150.1974.780.7480.4260.5550.530.5427.520.3568.190.8120.3970.5060.630.81312.490.57713.120.8720.3240.3921.0411.0411.0771.07718.020.82418.660.9270.2360.2690.831.30925.001.12725.850.9800.1670.1830.931.57832.361.43433.661.0300.1260.1351.031.85139.961.72241.750.1100.11075.5975.590.1161.132.0848.221.99850.481.1220.0820.0861.232.3956.652.2459.171.1660.1030.1081.332.7366.022.4868.851.2080.1290.1381.433.082.702.700.2950.29578.601.2490.1570.1711.533.3984.252.8989.171.2880.1950.2161.633.7494.503.0699.811.3270.2250.2551.734.10105.363.21110.831.3640.2561.831.83170.44170.444.44115.563.33122.351.4000.2920.3451.934.79126.753.44134.261.4350.3220.3892.035.13137.663.54146.721.4700.3530.4352.235.82160.853.681.5361.5368.818.810.4030.5162.436.55185.603.78195.831.6000.4530.6032.637.28209.603.86221.901.6610.4990.6912.838.02236.103.90248.301.7200.5380.7713.03263.30263.300.7420.7423.92275.301.7780.5740.8543.5310.79331.503.93342.401.9130.6471.0424.0312.88403.003.91408.802.0400.7011.2064.5315.01478.203.88478.202.1591.3531.3534.134.135.0317.07555.903.88545.902.2720.7691.4635.5319.12637.903.91671.402.3790.8061.6386.0320.9722.503.99687.002.4820.7991.6066.5322.9810.50759.00759.008.538.532.5810.8071.6477.0324.8898.504.33833.402.6760.8121.6707.5326.7987.904.59911.502.7680.8141.6808.0328.51075.004.90988.202.8570.8131.67630.230.23.1873.1871162.505.261067.502.9430.8101.6629.0331.91248.005.661149.603.0270.8071.6479.5333.51330.506.111323.203.1080.8171.69610.0335.11411.206.621318.400.7980.7981.600由以上數(shù)據(jù)作圖：電流與電子速率的關(guān)系。由圖可以看出，室溫下，Ip隨電子速率的增大，先會Ip法始終增大。而在液氮溫度下，氣體被凍結(jié)，電子的散射可以無視不計，所以Ip*與電子速率近似呈線性正相關(guān)關(guān)系系曲線。Ps、QL0.5<√(Ea-Ea0)<1，Ps、QL當(dāng)√(Ea-Ea0)在1左右時，Ps、QL到達(dá)最小，這一點的數(shù)據(jù)是：冉紹爾效應(yīng)。【小結(jié)】本次試驗是冉紹爾-湯森效應(yīng)的驗證明驗，有上