Fermilab Today

Five thousand pencil-shaped robots, densely nested in a metal hive, whir to life with a precise, dizzying choreography. Small U-shaped heads swivel into a new arrangement in a matter of seconds.

This preprogrammed routine will play out about four times per hour every night at the Dark Energy Spectroscopic Instrument. The robots of DESI will be used to produce a 3-D map of one-third of the sky. This will help DESI fulfill its primary mission of investigating dark energy, a mysterious force thought to be causing the acceleration of the expansion of the universe.

The tiny robots will be arranged in 10 wedge-shaped metal "petals" that together form a cylinder about 2.6 feet across. They will maneuver the ends of fiber-optic cables to point at sets of galaxies and other bright objects in the universe. DESI will determine their distance from Earth based on the light they emit.

DESI's robots are in development at Lawrence Berkeley National Laboratory, the lead in the DESI collaboration, and at the University of Michigan.

—Glenn Roberts Jr.

In Brief

All-Experimenters' Meetings scheduled monthly through September

For the duration of the accelerator shutdown, All-Experimenters' Meetings will move to a monthly schedule beginning today.

All-Experimenters' Meetings will take place the first Monday of the month in July, August and September. They will return to their weekly schedule in October.

Photo of the Day

Venus and Jupiter

Venus (right) and Jupiter draw closer together. This photo was taken the weekend of June 26. Photo: Chip Edstrom, AD

In the News

Hoped-for dark matter flash might instead be the corpses of stars

From New Scientist, July 1, 2015

Dark matter is keeping to the shadows. A potential sign of the mysterious stuff may actually be due to the husks of dead stars.

For decades astronomers have suspected the existence of a form of matter, called dark matter, that doesn't emit or absorb visible light and is five times more abundant in the cosmos than normal matter.

Since 2009, data from NASA's Fermi satellite have shown an unexplained excess of gamma rays at the centre of the Milky Way that look strikingly like dark matter particles annihilating each other and emitting high-energy light in the process.

Tip of the Week: Sustainability

Keeping track of our changing environment

This illustration shows the volume taken up by one metric ton of carbon dioxide. In 2013, the United States emitted the equivalent of 6.7 billion metric tons. By tracking how much greenhouse gas we emit and its various sources, we can work on reducing that number over time. Image: Carbon Visuals

In climate science, collecting the right data is critical to understanding what the future holds in a world with a changing climate. Of fundamental importance is tracking greenhouse gas emissions over time.

In April, the U.S. Environmental Protection Agency released the latest report documenting emissions with its Inventory of U.S. Greenhouse Gas Emissions and Sinks. This annual report dating back to 1990 tracks U.S. total annual emissions and removal of greenhouse gases across a variety of metrics. The inventory covers seven key greenhouse gases: carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride and nitrogen trifluoride.

Total overall emissions were 6.7 billion metric tons of carbon dioxide-equivalent in 2013. Emissions in 2013 were 9 percent below 2005 levels. The inventory shows a 2 percent increase in overall emissions in 2013 from 2012. The increase has been attributed to increases in energy consumption and greater use of coal over the period. The largest source of emissions by sector were power plants, accounting for 31 percent of the total. The transportation sector was the second-largest at 27 percent, followed by industry and manufacturing at 21 percent.

Fermilab began keeping a comprehensive inventory in 2008, the year we first began reporting to DOE's Sustainability Performance Office on our emission sources. Our largest source, similar to the U.S inventory, is energy consumption. Although we don't generate electricity on site, we do purchase it off the grid, and it dominates our emissions, accounting for 93 percent of greenhouse gases attributable to lab operations.

Big science requires big power, and one of the ways we minimize our impact is by purchasing Renewable Energy Certificates (RECs) for a portion of the power purchased. RECs are energy commodities that demonstrate proof that the electricity was generated from a renewable energy resource. Using RECs, in 2014 the lab reduced the impact from purchased power by 19 percent from the 2008 baseline, with the intention to increase the percentage over time to meet federal emission reduction goals.

In addition to aggressively looking at energy conservation opportunities for projects and site operations, we will strategically use RECs as offsets in years ahead to further reduce lab emissions.

—Eric Mieland

In the News

Space particles are helping map the inside of Fukushima

From Wired, July 1, 2015

In just about every industrial factory you'll see them: huge lead pipes. These move fluid — often super hot, or even steamed water. Over time, the fluids wear the pipes down. Or maybe they get dinged by a passing forklift. Or maybe changes in temperature cause tiny cracks to appear. Then the pipe bursts, and people get hurt.

Inspecting pipes is a pain in the tochus. Usually these pipes are covered in insulation and pumping hot, high pressure steam. To inspect them, you have to shut down the pipe, take it out of service, remove the insulation, then apply X-rays or ultrasound — both of which require special certification to use because of the radiation involved.