The ultrafast
"the ultrafast"
simplified schematic of "the ultrafast"
"The ultrafast", a high repetition tunable photoionization pump-probe mass spectrometer developed and constructed by Nureshan Dias and me at Berkeley Lab. The idea of this machine is to have a versatile mass spectrometer that can also probe dynamics, with a variety of sources to perform chemistry or bring molecules in the gas phase. So far, we have already performed REMPI of gas phase molecules at high repetition, investigate the liquid-vacuum interface with the leaky nozzle (see below), follow the ultrafast dynamics of the isolated anthracene dimer, probe products using UV-VIS spectroscopy of hydrocarbons in a hot nozzle.
We run a matlab code with a GAGE digitizer with on-board averaging for data acquisition at high repetition rate. There is fast live data analysis, but also post-processing with peak detection and automated spectral analysis.
Specifications:
Rep rate: up to 750 kHz
Max mass spectrum: length ~350 m/z at 50 kHz, resolution: at least 600 at 300 m/z
Source: continuous, skimmed molecular beam up with vaporization compartment up to 300 C. Optional SiC reactor with temperatures up to 1300 C
Pump: 310-10 000 nm (1.5 uJ, 50 um FWHM beam waist at 400 nm)
Probe: 115 nm or 345 nm (1 uJ at 345 nm)
Time resolution: Instrument response FWHM 0.497 ± 0.007 (pump 360 nm, probe 345 nm).
Maximum delay time: 2 ns
Discharge nozzle
Hot nozzle
Leaky nozzle
Desorption source. Topics in Current Chemistry, Gas-Phase IR Spectroscopy and Structure of Biological Molecules, Anouk M. Rijs and Jos Oomens, 2015
Above are photos or schematics of different sources I have used or developed, including an electrical discharge source to create a pulsed plasma, a SiC tube heated to above 1000 Celcius, a leaky nozzle to study vacuum-liquid interface, and a laser desorption source developed in the lab of Anouk Rijs
We also manage a reflectron TOF mass spectrometer at beamline 9.0.2 at the Advanced Light Source
Link to latest paper