摘要
本文报导了用4415.6AHe-Cd^+ CW激光获得的^(39)K_2分子C^1∏_u→X^1∑_g^+跃迁的激光诱导荧光(LIF)光谱。光谱分析表明,LIF先请来自C^1∏_u(v′=0,J′=53)→X^1∑_g^+(v″=0-11,J″=52,54)的R,P支跃迁。使用最小二乘法由上述跃迁拟合出X^1∑_g^+态的转振常数和C^1∏_u态的Te值。用^(39)K_2分子的RKR势计算了(v′=0,J′=53)→(v″= 0-11,J″=52,54)跃迁的光谱强度。理论计算和实验测量之间的符合是令人满意的。更细致的r重心近似分析表明:C^1∏_u→X^1∑_g^+的电偶极跃迁矩R_e(r)随核间距r的变化率为0.157debye/A(4.22A<r<4.71A)。
The LIF (laser induced fluorescence) spectrum from C^1Пμ→ X^I∑_8^+ of ^(39)K_2 dimer excited by 4415.6A H_e-C_d^+ CW laser line is reported. The sample of ^(39)K_2 was produced in heat pipe oven with buffer gas Ar. The LIF spectrum was measured by use of GDR-1000 modal double gratings monochromater. The intensity of spectrum was calibrated by tungsten standard lamp. The analysis of spectrum pointed out that LIF spectrum came from the R and P branches of C^IП_μ (v' = 0, J' = 53)→ X^1∑_g^+ (v' = 0 -11, J' = 52, 54). The rovibration constants of X~∑ + and Te value of C^1П_μ was fitted out by least-squares method. with the for- g mula of the emission spectrum I∝ v'R_cq_(v'v') the spectrum intensities of (v' = 0, J' = 53) - (v' = 0-11, J' = 52, 54) transitions of ^(39)K_2 was computed by use of RKR potentials. The agreement between the computed values and the experimen- tal one was satisfactory. Further analysis of r-centroid approximation showed that the changing ratio of the dipole transition moment R_e (r) of C^JП_μ→X^I∑_g^+ of ^(39)K_2 dimer with internuclear distancer could be deduced by formula (I_(exp)_(V'V')) / (I_(cal)_(v'v'))∝(R_e(r_(v'v'))) / R_0 = 1 + α / R_0 r_(v'v') where r_(v'v') = < v'|v' > / < v'|r|v' > was r-centroid computed. The result by use of least-squares fitting was |α / R_0| = -0.157 debye / A in 4.22A < r < 4.71 A.
