The 16th International Conference on Accelerator Mass Spectrometry

Development of Li molecular removal method that interferes with 14C measurement using laser

PSA-48

21 Oct 2024, 16:55

20m

Lobby and Hallway , 2nd Floor (( Poster session A should be set up in the morning.))

Poster New and Advanced AMS Techniques Poster Session A

Speaker

Junghun Park (KIGAM)

Description

Mass of Li molecule (Li2) is same to 14C, so 14C measurement is frequently interfered by it in using two plus ion of 14C after gas striping of AMS. Removal of Li molecule (Li2) is important in our AMS which use two plus ion of 14C. AMS generate negative ions of carbon (12C-, 13C-, 14C-) and Li2- in a source, which have binding energies of electron of 1.262eV, 982.35nm(14C-) and 0.42eV, 2.952nm (Li2-). Therefore, if laser of energy (1.166eV, 1064nm) between binding energies of electron in 14C and Li2- is incident on negative ions of 14C- and Li2-, one electron of Li2- can be detached but that of 14C- can’t be detached. Laser was equipped near injector magnet and is incident on negative ions (12C-, 13C-, 14C- and Li2-) on direction of Tandem accelerator after injector magnet. What the number of Li2 were decrease and what those of 14C were not changed were checked in E-ΔE spectrum of ionization chamber detector.

Presentation materials

laser_AMS16_abstract.docx