Research Highlights

The new superlattice photocathode, adapted by Jefferson Lab scientists for use in CEBAF, allows the use of readily available, fiber-based drive lasers, which require significantly less maintenance than laser types previously used in CEBAF. Introduction of these new lasers has reduced photo-injector downtime by more than 50% (from 2% total downtime to less than 1%).
Jefferson Lab continues to integrate the fruit of superconducting radiofrequency (SRF) R&D into the production of higher-performing accelerator components.
Jefferson Lab continues to develop innovative solutions to problems shared by the accelerator community. A common challenge in accelerators based on superconducting radiofrequency technology (SRF) is the presence of additional radiofrequency waves inside the accelerator cavities, in addition to the primary frequency needed for accelerating particles.
Prior research measuring protons in nuclei found that protons and neutrons, collectively called nucleons, may pair up briefly inside the nucleus of the atom in short-range correlations. These paired particles are imparted with high momentum in comparison to non-paired nucleons. This new study measured both protons and neutrons and found that in nuclei with more neutrons than protons, a greater fraction of protons pair up, thus giving the protons a higher-average momentum than the neutrons.
The determination of the pressure distribution inside the proton is the first measurement of a mechanical property of a subatomic particle. The measurement found that the proton’s building blocks, quarks, are subjected to a pressure of 100 decillion Pascal (1035) near the center of a proton, which is about 10 times greater than the pressure in the heart of a neutron star.
The weak force is one of the four fundamental forces in our universe, along with gravity, electromagnetism and the strong force. Researchers have made the first experimental determination of the weak charge of the proton, a measure of the precise strength of the weak force’s influence on the proton.