For more than half a century, researchers worldwide have worked to achieve fusion ignition in the laboratory, a major 21st-century challenge. The High Energy Density Physics (HEDP) group ) at MIT’s Center for Plasma and Fusion Science has focused on a fusion confinement inertia Approach (ICF), which uses a laser to detonate a fuel pellet in an ignition mission.
This group, which includes nine former and current MIT students, is critical to a historic ICF ignition experiment to be conducted in 2021; The results are announced on the anniversary of that success.
MIT has contributed to the success of the ignition program at the National Ignition Facilty for more than a decade by providing and using dozens of diagnostics made by MIT fellows and staff, which are critical. to evaluate the performance of an explosion, like an image. Image credit: Lawrence Livermore National Laboratory.
On August 8, 2021, researchers at the National Ignition Facility (NIF), Lawrence Livermore National Laboratory (LLNL), used 192 laser beams to illuminate the inside of a small cylinder gold encapsulation of a spherical capsule filled with deuterium-tritium fuel in a mission to generate substantial fusion energy. Although the researchers had followed the process many times before, using different parameters, this time the ensuing explosion produced a historic fusion yield of 1.37 megaJoules, as measured by one neutron diagnostic kit. These include the Magnetic Recoil Spectrometer (MRS) developed and analyzed by MIT. This result is published year Physical assessment letter on August 8, the one-year anniversary of the groundbreaking development, clearly indicates that the first controlled fusion experiment has reached flammability.
Regulated by the Lawson criterion, the plasma ignites when the internal fusion heating power is high enough to overcome the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop that increases very rapidly. plasma temperature. In the case of ICF, ignition is the state in which the fusion plasma can initiate a “fuel-burning propagation” into the surrounding cold and dense fuel, creating the possibility of a high fusion energy gain.
“This historic result certainly demonstrates that ignition threshold is a practical concept, with theoretical calculations well predicted and fusion plasma that can be ignited in the laboratory,” said Head of HEDP. said Johan Frenje.
The HEDP department has contributed to the success of the ignition program at NIF for more than a decade by providing and using dozens of diagnostics made by MIT fellows and staff, which are critical. to evaluate the performance of an explosion. Hundreds of co-authors on the paper attest to the collaborative effort that has reached this milestone. MIT contributors include sole student co-authors.
“Students are responsible for making and using diagnostics to obtain data critical to the ICF program at NIF,” says Frenje. “Responsible for running diagnostics at NIF has allowed them to participate actively in the scientific dialogue and thus have direct exposure to cutting-edge science.”
Written by Plasma Science and Fusion Center
Source: Massachusetts Institute of Technology
