What enabled ignition at the NIF? The National Ignition Facility
achieved breakeven on December 5th,
obtaining more than 3 MJ from an
input of 2.05 MJ.
What have they been doing differently,
starting this summer?
Laser shots this year have been a little
more powerful, supplying around
10% more energy than before.
But apparently there have also been some
changes to the hohlraum,
or to laser timing details,
for better hydrogen fusion stability and yield.
What explains the dramatically
improved shot efficiencies,
increasing to 70% and
then this month to 150% ?
 A: Zylstra, Hurricane, et al., Burning plasma achieved in inertial fusion, from January, hints at their 2022 plans.

Two tactics have been used to enable symmetry control with more efficient hohlraums driving larger capsules: adjusting cross-beam energy transfer between the outer to inner beams by changing the laser wavelength separation (Δλ); and incorporating a pocket in the hohlraum wall at the outer beam location to delay the bubble propagation.

At the time, each shot delivered 1.9 MJ input energy,
and baseline fusion output was 50 kJ.
The two tactics improved output to 170 kJ.
Apparently diamond was incorporated into the hohlraum
design -- unclear whether it is reusable from shot to shot.
The article goes on to list techniques that may have been used this year:

the ICF programme at NIF is pursuing several approaches that can enable additional progress: reducing degradation mechanisms including low-mode asymmetry and radiative losses from mix, further increasing energy coupled to the capsule, and improving compression of the fuel.

