實驗-金屬電子逸出功測量實驗報告

【數(shù)據(jù)處理】表1測定鎢的逸出功√UaIf/A0.600.620.640.660.680.700.724Ia/A3.20E-055.20E-058.50E-051.35E-042.10E-043.19E-044.78E-04lgIa-4.49485-4.284-4.07058-3.86967-3.67778-3.49621-3.320575Ia/A3.30E-055.40E-058.70E-051.38E-042.16E-043.29E-044.95E-04lgIa-4.48149-4.26761-4.06048-3.86012-3.66555-3.4828-3.305396Ia/A3.40E-055.60E-059.00E-051.42E-042.22E-043.39E-045.05E-04lgIa-4.46852-4.25181-4.04576-3.84771-3.65365-3.4698-3.296717Ia/A3.50E-055.70E-059.10E-051.45E-042.26E-043.45E-045.14E-04lgIa-4.45593-4.24413-4.04096-3.83863-3.64589-3.46218-3.289048Ia/A3.50E-055.80E-059.30E-051.47E-042.30E-043.51E-045.23E-04lgIa-4.45593-4.23657-4.03152-3.83268-3.63827-3.45469-3.28159Ia/A3.60E-055.90E-059.50E-051.50E-042.34E-043.57E-045.32E-04lgIa-4.4437-4.22915-4.02228-3.82391-3.63078-3.44733-3.2740910Ia/A3.70E-056.00E-059.60E-051.52E-042.38E-043.63E-045.40E-04lgIa-4.4318-4.22185-4.01773-3.81816-3.62342-3.44009-3.2676111Ia/A3.70E-056.10E-059.80E-051.55E-042.41E-043.71E-045.48E-04lgIa-4.4318-4.21467-4.00877-3.80967-3.61798-3.43063-3.26122由圖可知：0.60V時logI0=-4.474;0.62V時logI0=-4.262;0.64V時logI0=-4.055;0.66V時logI0=-3.855;0.68V時logI0=-3.660;0.70V時logI0=--3.479;0.72V時logI0=-3.307;If/A0.600.620.640.660.680.700.72logIo-4.474-4.262-4.055-3.855-3.66-3.479-3.307Io3.36E-055.47E-058.81E-050.000140.0002190.0003320.000493T1880191419451978201020402074log(Io/T^2)-11.0223-10.8259-10.6328-10.4475-10.2664-10.0983-9.940621/T0.0005320.0005220.0005140.0005060.0004980.000490.000482根據(jù)表中數(shù)據(jù)作圖如上：直線斜率：m=-21987逸出電勢：Φ=m-5.04*逸出功：eV=4.36eV與逸出功公認(rèn)值4.54eV比較，誤差Er=3.96%表3陽極電壓Ua與Ic關(guān)系表Ua/v1.002.003.004.005.006.00Ic/A0.1100.1360.1560.1750.1930.211Ic20.0121000.0184960.0243360.0306250.0372490.044521斜率：K=155.6；陽極內(nèi)半徑a=3.9*10-3;線圈長度：l=1.47*10-2;;線圈數(shù)：N=990匝；線圈內(nèi)半徑：r1=0.021m;線圈外半徑：r2=0.028m;真空磁導(dǎo)率：4μ荷質(zhì)比e/m=1.7588*1011（c/Kg）K’=0.0197;K=em*a^28KK=155.6;所以e/m=2.108*1011；【思考與討論】3．答：理查遜的直線法在于將原先很復(fù)雜的公式簡單化，而且變成線性化。便于觀察和測量。4．答：在測量樣機(jī)電流的過程中，必須保持燈絲電流不變（0.72mA），參考點不能變，因為如果變化了，逸出功也隨之改變?！緦嶒灴偨Y(jié)】臨界點Q的選