MeV Photoelectron Spectrometer for Ultrastrong field Laser-Atomic and Molecular Interactions: Next Generation Spectroscopy

Spectroscopy techniques, such as time-of-flight, revolutionized measurements of laser matter interactions. Terawatt and petawatt laser systems can create focused intensities exceeding 10²⁰ W/cm². Traditional experimental techniques are unable to quantify the > 100 keV photoelectrons from the interaction of these intensities with atoms and molecules. A new generation of spectrometers and sample preparation is required. At this time, a ‘breakthrough’ technology for measuring the interaction of atoms and molecules in ultrastrong fields has not emerged. We present a magnetic deflection spectrometer for ultrastrong field laser experiments in a focused geometry with atoms and molecules. Beta decay samples ¹⁴C, ¹³⁷Cs and ²⁰⁴Tl are used to calibrate the spectrometer over its energy range from 20 keV to 2 MeV. The UHV spectrometer employs a rotatable magnet analyzer in vacuum to measure photoelectrons emitted into polar angles from 10 to 100 degrees from the laser wave vector k. Recent spectra for noble gases and chloromethane will be presented.