Berkelium (Bk) X-ray absorption edges

Absorption edges of berkelium

Jump ratio is the photoabsorption just above the edge divided by the photoabsorption just below it. Fluorescence yield is the probability that a core hole in that shell decays by emitting an X-ray. Both are dimensionless. The lab can scan across edges strictly between 100 $\mathrm{eV}$ and 100 $\mathrm{keV}$; other edges are listed for reference. A listed edge with jump ratio 1 has no step for thickness planning.

Transmission, fluorescence or electron yield

${\mathrm{L}}_1$, ${\mathrm{L}}_2$, ${\mathrm{L}}_3$, ${\mathrm{M}}_1$, ${\mathrm{M}}_2$, ${\mathrm{M}}_3$, ${\mathrm{M}}_4$ and ${\mathrm{M}}_5$ are hard X-ray edges in the lab's classification (2 $\mathrm{keV}$ and above). The sample planner suggests transmission when the edge step is large enough relative to total attenuation. For a small step, as in a dilute absorber, it suggests fluorescence. Concentration alone does not decide the measurement mode.

${\mathrm{N}}_1$, ${\mathrm{N}}_2$, ${\mathrm{N}}_3$, ${\mathrm{N}}_4$, ${\mathrm{N}}_5$, ${\mathrm{N}}_6$, ${\mathrm{N}}_7$, ${\mathrm{O}}_1$, ${\mathrm{O}}_2$, ${\mathrm{O}}_3$, ${\mathrm{O}}_4$ and ${\mathrm{O}}_5$ are soft X-ray edges in the lab's classification (below 2 $\mathrm{keV}$). Transmission generally needs thin films or membranes, so the planner suggests fluorescence or electron yield. The fluorescence yield at ${\mathrm{N}}_1$, ${\mathrm{N}}_2$, ${\mathrm{N}}_3$, ${\mathrm{N}}_4$, ${\mathrm{N}}_5$, ${\mathrm{N}}_6$, ${\mathrm{N}}_7$, ${\mathrm{O}}_1$, ${\mathrm{O}}_2$, ${\mathrm{O}}_3$, ${\mathrm{O}}_4$ and ${\mathrm{O}}_5$ is below 0.05, where the lab suggests considering total electron yield.

These are planning rules of thumb. Sample thickness, self-absorption and the beamline's energy range and detectors still matter. The lab simulates transmission; it does not simulate fluorescence or electron-yield detector counts.