FD-1型多功能超声分子束装置的研制

FD-1 UNIVERSAL SUPERSONIC MOLECULAR BEAM APPARATUS

本文介绍了一种探测器可转动的新型多功能超声分子束设备,探测器的内外二室分别由两台离子泵进行抽气(高分辨率四极滤质器及离子-电子倍增器置于探测器的内室)。这内外二室各经不锈钢波纹管与离子泵相连接,因此,在离子泵位置固定的情况下,探测器可围绕碰撞中心转动120度。高压气体经喷口绝热膨胀及三级差分抽气而形成分子束,在喷管中氩气压强为600Torr时,分子束设备碰撞中心处的束流强度可达1.4×10^(17)个分子/厘米~2·秒,用可转动的探测器测得分子束发散角的半宽度约为2度。文中也给出了分子束由固体表面散射后的角分布曲线。最后,介绍了在激光诱导气固相反应中,反应速率将随入射氯分子平动能的增大而明显增加。

The new design of an universal molecular beam apparatus with a rotatable detector isdescribed. The detector comprises a high resolution quadrupole mass filter and an ion-electronmultiplier which is nested in the innermost of two chambers, each pumped by a separate ionpump. Two stainless steel flexible tubes are used to connect the ion pumps with two cham-bers of the detector respectively. Therefore tbe detector can be rotated around the collisioncenter about 120 degrees with stationary location of the ion pumps. Supersonic molecular beamis formed by a nozzle with high backing pressure and three-stage differential pumping re-gion. The argon beam intensity is 1.4×10^(17) molecules/cm^2·s at the collision center with thebacking pressure of 600 Torr. The FWHM of the spatial distribution is about 2 degrees mea-sured by the rotatable detector and the angular distribution of the molecular beam scatteredfrom surface is measured as well.Furthermore the interesting result of the obvious enhance-ment of laser-induced gas-surface reaction by increasing the translational energy of incidentchlorine molecules is reported.