In thermal collisions between Xe(nf) Rydberg atoms and NH(,3) collisional depopulation of the nf state occurs through at least three distinct mechanisms: n-changing collisions, l-changing collisions, and ionizing collisions. Using selective field ionization, the total collisional depopulation rate constants k(,d) are measured for laser-excited Xe(nf) atoms in the n range of 22 to 39. The magnitudes of k(,d) are large, corresponding to reaction cross sections comparable to the geometric size of the Xe(nf) atom at n = 22. In the n range of 25 to 40, Xe('+) ion production provides an absolute measure of the rate constants for collisional ionization. Approximate rate constants for n-and l-changing collisions are also presented for the 31f state. In these experiments, one finds that the state-changing collision rate constants are fairly independent of n and are determined largely by the l-changing collisions. The collisional ionization rate constants measured are smaller than the state-changing rate constants and increase with increasing n, ranging between 0.2 and 4.6 x 10('-7) cm('3)/sec for n between 25 and 40. The present results are compared to those of recent theoretical calculations.
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机译:在Xe(nf)Rydberg原子与NH(,3)之间发生热碰撞时,nf状态的碰撞减少通过至少三种不同的机制发生:n碰撞,l碰撞和电离碰撞。使用选择性场电离,测量n范围为22至39的激光激发Xe(nf)原子的总碰撞失速速率常数k(,d)。k(,d)的大小较大,对应于反应横截面与n = 22时Xe(nf)原子的几何尺寸相当。在25至40的n范围内,Xe('+)离子的产生提供了碰撞电离速率常数的绝对度量。还给出了31f状态下n次和l次碰撞的近似速率常数。在这些实验中,人们发现状态变化碰撞率常数与n完全无关,并且很大程度上由l变化碰撞确定。测得的碰撞电离速率常数小于状态变化速率常数,并且随着n的增加而增加,对于介于25和40之间的n,范围为0.2到4.6 x 10('-7)cm('3)/ sec。与最近的理论计算比较。
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