A liquid-microjet(LJ)linear time-of-flight(TOF)mass spectrometer,coupled with a femtosecond laser ionization source,has been designed for direct measurements of mass spectra of liquid aqueous solutions.Two main featur...A liquid-microjet(LJ)linear time-of-flight(TOF)mass spectrometer,coupled with a femtosecond laser ionization source,has been designed for direct measurements of mass spectra of liquid aqueous solutions.Two main features of our designed spectrometer involve the coupling of a liquid microjet nozzle to a conventional ion optics and the application of femtosecond pulses for mass spectral ionization.The detailed design,construction,and simulation of this new spectrometer are presented.More importantly,we combined the experimental tests with the simulated electric fields and ion trajectories to investigate the performance of the designed spectrometer,especially the kind of disturbances of the nozzle electric field on the conventional ion optics.In our current design,the optimal E/R(E:extractor,R:repeller)electrode voltage ratio was found to be∼0.71 when the voltages on the R,E and G(ground)electrodes were set to be 1500,1060 and 0 V,respectively,whilst the voltage on the N nozzle electrode was required to be around 1250 V.The capability of the designed spectrometer has been demonstrated by recording the simulated mass spectra of the water,benzene and cytidine with their mass/charge ratios of 18,76 and 243,respectively.This work shall be helpful for the development of new all-liquid-phase mass spectral technology to be employed in the diagnosis of diseases by the mass analysis of human body fluids.展开更多
High-intensity laser–plasma interactions produce a wide array of energetic particles and beams with promising applications.Unfortunately,the high repetition rate and high average power requirements for many applicati...High-intensity laser–plasma interactions produce a wide array of energetic particles and beams with promising applications.Unfortunately,the high repetition rate and high average power requirements for many applications are not satisfied by the lasers,optics,targets,and diagnostics currently employed.Here,we aim to address the need for high-repetition-rate targets and optics through the use of liquids.A novel nozzle assembly is used to generate highvelocity,laminar-flowing liquid microjets which are compatible with a low-vacuum environment,generate little to no debris,and exhibit precise positional and dimensional tolerances.Jets,droplets,submicron-thick sheets,and other exotic configurations are characterized with pump–probe shadowgraphy to evaluate their use as targets.To demonstrate a highrepetition-rate,consumable,liquid optical element,we present a plasma mirror created by a submicron-thick liquid sheet.This plasma mirror provides etalon-like anti-reflection properties in the low field of 0.1%and high reflectivity as a plasma,69%,at a repetition rate of 1 k Hz.Practical considerations of fluid compatibility,in-vacuum operation,and estimates of maximum repetition rate are addressed.The targets and optics presented here demonstrate a potential technique for enabling the operation of laser–plasma interactions at high repetition rates.展开更多
基金supported by the Knowledge Innovation Program of Wuhan-Basic Research(Nos.2023020201010084,2022010801010134)the National Key Research and Development Program of China(No.2019YFA0307700)the National Natural Science Foundation of China(Nos.12274418,22273116,12074389,11974381,22363011).
文摘A liquid-microjet(LJ)linear time-of-flight(TOF)mass spectrometer,coupled with a femtosecond laser ionization source,has been designed for direct measurements of mass spectra of liquid aqueous solutions.Two main features of our designed spectrometer involve the coupling of a liquid microjet nozzle to a conventional ion optics and the application of femtosecond pulses for mass spectral ionization.The detailed design,construction,and simulation of this new spectrometer are presented.More importantly,we combined the experimental tests with the simulated electric fields and ion trajectories to investigate the performance of the designed spectrometer,especially the kind of disturbances of the nozzle electric field on the conventional ion optics.In our current design,the optimal E/R(E:extractor,R:repeller)electrode voltage ratio was found to be∼0.71 when the voltages on the R,E and G(ground)electrodes were set to be 1500,1060 and 0 V,respectively,whilst the voltage on the N nozzle electrode was required to be around 1250 V.The capability of the designed spectrometer has been demonstrated by recording the simulated mass spectra of the water,benzene and cytidine with their mass/charge ratios of 18,76 and 243,respectively.This work shall be helpful for the development of new all-liquid-phase mass spectral technology to be employed in the diagnosis of diseases by the mass analysis of human body fluids.
基金supported by the Air Force Office of Scientific Research under LRIR Project 17RQCOR504 under the management of Dr. Riq Parraprovided by the AFOSR summer faculty program
文摘High-intensity laser–plasma interactions produce a wide array of energetic particles and beams with promising applications.Unfortunately,the high repetition rate and high average power requirements for many applications are not satisfied by the lasers,optics,targets,and diagnostics currently employed.Here,we aim to address the need for high-repetition-rate targets and optics through the use of liquids.A novel nozzle assembly is used to generate highvelocity,laminar-flowing liquid microjets which are compatible with a low-vacuum environment,generate little to no debris,and exhibit precise positional and dimensional tolerances.Jets,droplets,submicron-thick sheets,and other exotic configurations are characterized with pump–probe shadowgraphy to evaluate their use as targets.To demonstrate a highrepetition-rate,consumable,liquid optical element,we present a plasma mirror created by a submicron-thick liquid sheet.This plasma mirror provides etalon-like anti-reflection properties in the low field of 0.1%and high reflectivity as a plasma,69%,at a repetition rate of 1 k Hz.Practical considerations of fluid compatibility,in-vacuum operation,and estimates of maximum repetition rate are addressed.The targets and optics presented here demonstrate a potential technique for enabling the operation of laser–plasma interactions at high repetition rates.
基金This work was supported by the National Key Researchand DevelopmentProgramof China(No.2019YFA0307700)the National Natural Science Foundation of China(No.12274418,No.22273116,No.12074389,No.11974381,and No.22363011)the Knowledge Innovation Program of Wuhan-Basic Research(No.2022010801010134 and No.2023020201010084).
