Upgrading On Hexapole Setup And The Calculation For The Stark Effect Of Asymmetric Top Molecules

The space manipulation for molecular quantum states is one of the hot topics which have been widely concerned in the atomic and molecular researches.In the molecular quantum control,the state-selection,alignment and orientation can be achieved,which have a positive and important influence on the experiments about atoms and molecules.For example,they are applied to ionization and dissociation of molecules,Electron Diffraction,High Harmonic Generation and so on.The alignment and orientation of molecules can be realized in magnetic field,electric field and laser field,and these fields can also be combined.The effects of molecular alignment and orientation vary with the methods usedThe method based on combining non-uniform electrostatic field with femtosecond laser field is used in our research group to realize the alignment and orientation of molecules,Then the experiments of ionization and dissociation of related molecules,photoelectron imaging and so on are carried out.This time,we upgraded and reformed the original hexapole equipment.In this paper,the process and principle of upgrading and transformation are introduced in detail Firstly,the beam source chamber is added a new 200 mm long cavity(buffer chamber)to realize the second-order vacuum difference.In the hexapole chamber,the hexapole device was mainly reformed.Three sets of hexapole devices with the same length and different diameter were redesigned and manufactured.Beam stop is added in the middle of the hexapole and at the end of the hexapole device to effectively block some unwanted rotational dynamics and some molecules which are not affected by the hexapole electric field force.Under the premise of guaranteeing the vacuum degree of the cavity,the three-dimensional adjustment of the hexapole device outside the cavity is realized.In the detection chamber,a new detachable cavity with a length of 200 mm is added,which is simulated by Simion software.The purpose of prolonging the detection chamber is to be used in the measurement of ion correlation experiments.The whole supporting device of the experimental chamber was reprocessed and manufactured,which can be disassembled and changed to assemble supporting device.Compared with the previous support improvement,it is more convenient to maintain and safeguard the setup.On the other hand,in theory,we have completed the construction of rotational wave function of asymmetric top molecule,and calculated the energies of different rotational levels in ab-mixed type asymmetric top molecule(methanol molecule).The energy changes of methanol molecule(M=1 and M=2)under the first-order Stark effect in a uniformly varying field are also calculated.The results show |201>?|2-21>.|111>?|202>?|2-12>?|2-22>rotational states have positive Stark effect in the external field,if only the first-order Stark effect is considered.