5-Jun-2012 Snubbed protons tattle on neutron structure
Protons and neutrons are the fraternal twins of the sub-atomic world and the building blocks of all atomic nuclei. While similar in many respects, it's their differences that give them their unique properties. Now, scientists are exploiting these differences to gain deeper insight into these fundamental particles that build our visible universe.
29-Nov-2011 Scientist wins energy award at technology event
Xin Zhao has won a World Technology Network award in the individual Energy category for innovative work of "the greatest likely long-term significance" in his field. Zhao designed and patented a supercapacitor that would use graphene. The invention could someday see batteries in electric vehicles and similar devices boosted or replaced by high-power, high-capacity, fast-charge/discharge energy storage systems using graphene.
10-Nov-2011 Building block detectors for plants
While a plant's overall health can often be determined through simple observation, researchers sometimes need to see what's happening on the inside. That's where Jefferson Lab group leader Drew Weisenberger and his colleagues come in. They are working to develop tools that can image inside plants.
29-Jul-2011 Result tickler: Lead nucleus may bury positive side under neutral facade
Results from the Lead (Pb) Radius Experiment (PREx), performed last year at Jefferson Lab, suggest that the nucleus of a lead atom buries its positive "personality" beneath a neutral exterior. The preliminary result is consistent with the idea that neutrons form a kind of "neutron skin" around the protons in the nucleus in heavy nuclei. It is important for understanding heavy nuclei and for theoretical equations that describe the life cycles of neutron stars.
29-Jun-2011 Odd particle left out in the cold
The old saying birds of a feather flock together may also be true for the smallest bits of matter. According to a study recently published in Physical Review Letters, like particles inside protons and neutrons band together, leaving the odd one out.
6-Oct-2008 Bright light/dark matter: Free-electron lasers enter the realm of particle physics
While two accelerators have been operating at Jefferson Lab for more than a decade, only one was known for its research probing the particles that make up our universe. But things have changed. A particle physics experiment recently performed with Jefferson Lab's Free-Electron Laser, powered by the lesser-known and smaller accelerator, has had its results published in Physical Review Letters.
2-May-2008 'Skinny' pions sail through nucleus
A recent Jefferson Lab experiment may have demonstrated the onset of color transparency for pions, a necessary ingredient for interpreting related experimental results in nuclear and particle physics. The experiment was performed in Jefferson Lab's Experimental Hall C.
31-Jan-2008 Spin in the neutron
Physicists were in a whirl after measurements in the '80s revealed that the spins of the individual building blocks of the proton don't add up to the proton's actual spin. The so-called "proton spin crisis" spurred efforts to pin down where protons -- and neutrons -- get their spin. Pioneering measurements in Jefferson Lab's Hall A have opened the door for measuring some suspected sources of the neutron's spin.
16-Oct-2007 Energy savings deeply rooted at Jefferson Lab
When it comes to energy savings, Jefferson Lab has given a new meaning to dirt cheap. The lab uses a geothermal well system to control heating and cooling on two floors of one wing of its main administrative building. The wing, known as the F Wing, is a three-story, 61,000-square-foot addition that was constructed in 2005.
14-Aug-2007 Using generalized particle distributions: Research collaboration seeks 3-D image of the proton
A computed tomography -- CT -- scan can help physicians pinpoint minute cancer tumors, diagnose tiny broken bones and spot the early signs of osteoporosis. Now physicists are using the principles behind the procedure to peer at the inner workings of the proton. In a recent experiment, members of Jefferson Lab's Deeply Virtual Compton Scattering collaboration found that it will be possible to construct three-dimensional images of the building blocks of the proton.
14-Aug-2007 Studying the universe through pions
Pions are some of matter's simplest particles. They're built from the same building blocks as protons and neutrons -- quarks. The pion is the simplest particle built of quarks. The quarks are "glued" together by the strong force -- a fundamental force of nature that also binds quarks to form protons and neutrons. Studying the simple pion and its properties can reveal information about matter in the universe, where it came from and how it's held together.
31-Jul-2007 Reaching new heights in accelerator technology
The International Linear Collider is designed to collide high-energy electrons with high-energy positrons (electrons' antimatter counterparts). Once built, the ILC will serve as a powerful tool for scientists to address many of the most compelling questions of the 21st century -- regarding the fundamental nature of matter, energy, space and time, dark matter, dark energy and extra dimensions.
31-Jul-2007 Exploring the universal glue
In Jefferson Lab's Hall C, an international collaboration of nuclear physicists, the Fpi collaboration, is studying how the strong force combines nature's fundamental building blocks into the lightest particle built of quarks: the pion.
19-Jul-2007 Researchers' hottest new laser beams 14.2kW
On Oct. 26, Free-Electron Laser (FEL) team members knew they were within reach of a goal they'd pursued for two years. They were aiming to produce 10 kW of laser light at an infrared wavelength of 1.61 microns. On that day, they blew past the milestone to produce 11.7 kW. Just four days later, on Oct. 30, they coaxed another two kW out of the machine setting the record even higher at 14.2 kW.
9-Jul-2007 Lab enhances scientific data sharing with cutting-edge connection
In early 2005, researchers affiliated with Hall B wanted to transfer raw data from a recent experiment from the tape silo to computers offsite -- a task that without interruption would have taken the Lab's existing network connection almost seven days. Jefferson Lab's newly upgraded network connection is able to transfer data at a rate of up to 10 Gigabits per second, so that same transfer can now be completed in just 2.5 hours.
5-Jul-2007 Big bite is reborn
At Jefferson Lab's recent Users Meeting, DOE's Dennis Kovar and NSF's Brad Keister emphasized the funding agencies' commitment to pursuing a cohesive nuclear physics research program in the United States. For instance, Jefferson Lab is funded by DOE; however, NSF provides for many of the Lab's Users and students and some of the instrumentation used in experiments, such as the recently upgraded BigBite spectrometer.
8-Aug-2006 CEBAF's beam polarization gets a boost
In the last year, the polarization of CEBAF's electron beam has increased by more than 10 percent to over 86 percent polarization. This vast improvement in polarization, or the percentage of electrons spinning in one direction, has reduced the amount of beam time needed to complete precision experiments like G-Zero and HAPPEx. It's the result of work by the Electron Gun Group, which has spent the last two years pushing the boundaries of photocathode physics.
8-Aug-2006 Jefferson Lab's newest cluster computer takes shape
Unlike a regular computer -- whose "brain" consists of one or perhaps two processors -- a cluster computer's brain can contain hundreds or even thousands of individual processors, called nodes -- all wired together. To solve a problem, the cluster splits the problem into parts, and each node computes its designated part and shares the result with other nodes to produce the final solution.
4-Aug-2006 Determining how spin arises in the nucleon
In scattering experiments, the momentum transferred to a nucleon target from the incident electron is a primary characteristic of the interaction. Large momentum transfer reactions
probe the fundamental quarks and gluons (collectively known as partons)
that make up the nucleon.
30-Jul-2006 Hypernuclei at Jefferson Lab
In 1827, Robert Brown observed that pollen grains floating in a drop of water jiggled constantly. The phenomenon became known as Brownian motion. Over 75 years later, Einstein proposed that the pollen grains were being jostled by the molecules of water. The impurity (pollen grains) Brown had added to the water allowed Einstein to deduce the presence of individual water molecules and describe at least one of their properties.
28-Jul-2006 Spin identity
Spin is an essential and fascinating phenomenon in the physics of elementary particles. Spin was first defined by Goudsmit and Uhlenbech in 1925, and has played a dramatic role in elementary particle physics, sometimes refuting theories and at other times supporting them. During Experiment E99-117 at Jefferson Lab, an international collaboration collected precision data on the spin of the neutron. Results from this experiment provide evidence that our current understanding of spin is not totally valid.
The Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time.