Laser microprobe for the study of noble gases and nitrogen in single grains: A case study of individual chondrules from the Dhajala meteorite

Journal of Earth system science

R R Mahajan1¹  S V S Murty1¹ 

[1] Planetary and Geosciences Division, Physical Research Laboratory, Ahmedabad 380 009, India$$

关键词: Laser;    mass spectrometer;    noble gases;    nitrogen;    chondrule;    meteorite.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

A laser microprobe capable of analysing nitrogen and noble gases in individual grains with masses less than a milligram is described. It can be used in both continuous wave (CW) mode, useful for stepwise heating of an individual grain, as well as in pulsed mode, useful for ablating material from a small selected area of a sample, for gas extraction. We could achieve low blanks (in ccSTP units) for 4He (4.8 × 10-12), 22Ne(1.0 × 10-12), 36Ar(1.0 × 10-13), 84Kr(2.9 × 10-14), 132Xe(2.6 × 10-14), and N (87 pg), using this system. Preliminary data for individual chondrules from the Dhajala meteorite show that noble gases and nitrogen from grains as small as 170 microgram can be analysed using the present laser microprobe setup. The amount of trapped neon in Dhajala chondrules is very small, and nitrogen in the chondrules is isotopically heavier as compared to the bulk meteorite.

【 授权许可】

Unknown