Future LHC super-magnets pass muster

Scientists in the US LHC Accelerator Research Program have successfully tested superconducting magnets needed to increase LHC collisions tenfold.

Courtesy of: Dan Cheng, Helene Felice

Courtesy of: Dan Cheng, Helene Felice

by Kelly Izlar

In the past four years, scientists at the Large Hadron Collider have accomplished unprecedented feats of physics, all with their particle accelerator working at half its design capacity.

The future is looking even brighter, literally.

Last week the US LHC Accelerator Research Program, or LARP, successfully tested a new type of magnet required to boost the power of the LHC—or the luminosity of its particle beams—by a factor of 10.

LARP is a collaboration among the US Department of Energy’s Brookhaven, Fermi, Lawrence Berkeley and SLAC national laboratories, working in partnership with CERN.

The improved magnets are one of the most critical components in a series of LHC upgrades that will be implemented over the next ten years. In the accelerator, magnets squeeze and focus beams of charged particles, directing them to a point of high-energy collision inside a detector. The new magnets, along with other upgrades, will allow the LHC to collect a larger amount of data at higher energies, making it possible to search for more massive potentially hidden particles than ever before.

Lucio Rossi, leader of the high luminosity project at CERN, says the improved LHC could illuminate unexplored corners of physics.

If you enter a dark room with only a candle, the room will be dim, and the candle will soon burn out, he says. But if you have a high-powered flashlight, not only can you see more of the room, but you also have enough time to get a good look around.

“Thanks to this magnet, we will have more collisions, more statistics and more rare events,” Rossi says. “If there is physics beyond the Standard Model, these magnets will shed light on it.”

Like the magnets that currently steer particles through the LHC, the new magnets are superconducting. A superconductor is a material that allows electric current to flow without resistance, creating a strong magnetic field.

The current LHC magnets are made of a metal alloy called niobium titanium. While they have performed remarkably well, there’s a limit to the amount of magnetic field they can sustain—and they’ve gone almost as far as they can go.

For the LHC to continue pushing the boundaries of high-energy physics, physicists plan to switch to magnets made out of niobium tin. Niobium tin has a greater tolerance to heat than niobium titanium, which means it has a larger window of superconductivity and can sustain a higher magnetic field longer.

However, there’s a catch; although niobium tin is a better superconducting material, it’s brittle and sensitive to strain.

“Think of a steel wire you would use for home repairs,” says Berkeley Lab’s GianLuca Sabbi, who directed the development of the new magnets. “You can bend it, and it won’t break. This is the case for niobium titanium, but niobium tin is more like glass.”

This presents some serious technical challenges because making a traditional superconducting magnet requires drawing the alloy into thin wires, gathering those wires into high current cables and then tightly winding them into an accelerator coil. If scientists took these steps, niobium tin would shatter.

US LHC Accelerator Research Program scientists get around this issue by following a clever recipe. First, they coil the “raw” ingredients of niobium tin—the metals that combine to create it—and then put the whole device into a special furnace for a high temperature heat treatment, which melds the components into a superconductor with the desired shape already intact.

At this point, it becomes sensitive to strain, so the scientists fill all the gaps and voids with an epoxy, which glues the brittle material together, providing the support the fragile wires need to withstand the harsh environment of the LHC.

The new technology has applications beyond high-energy physics. Plans are already in motion to incorporate these magnets into medical practices such as imaging and cancer treatment.

As the LHC continues to be streamlined, physicists hope to see further beyond the veil, piecing together the truth behind dark matter, dark energy, extra dimensions and other mysteries. At this scale of luminosity, previously undiscovered particles may even begin to appear.
– See more at: http://www.symmetrymagazine.org/article/july-2013/future-lhc-super-magnets-pass-muster#sthash.HIZmS9vf.dpuf

Black holes, TeV-scale gravity and the LHC

The geometry of a higher-dimensional black hole on the brane

The geometry of a higher-dimensional black hole on the brane

Elizabeth Winstanley
Over the past 15 years models with large extra space-time dimensions have been extensively studied.
We have learned from these models that the energy scale of quantum gravity may be many orders of magnitude smaller than the conventional value of 1019 GeV.
This raises the tantalizing prospect of probing quantum gravity effects at the LHC.
Of the possible quantum gravity processes at the LHC, the formation and subsequent evaporation of microscopic black holes is one of the most spectacular.
We give an overview of some of the fundamental ideas of the large extra dimensions scenarios and the resulting black hole processes at the LHC.
Read more at http://arxiv.org/pdf/1306.5409v1.pdf

LHC upgrade to open up ‘new realm of particle physics’

lhcEngineers have begun a major upgrade of the Large Hadron Collider (LHC).

Their work should double the energy of what’s already the most powerful particle accelerator in the world.

BBC News is the first to be allowed to see inside the LHC – on the French-Swiss border – to watch the work being carried out.

Scientists believe the upgrade will enable them to discover new particles which will lead to a more complete theory of how the Universe works.

A project leader with the LHC’s Atlas experiment, Dr Pippa Wells told BBC News that there was much more to come from the LHC.

“The past two years have been the most exciting in my time as a particle physicist. People are absolutely fired up. They’ve made one new discovery (the Higgs) and they want to make more discoveries with the new high energies that the upgrade will give us. We could find a new realm of particle physics”.

I was taken by the technical coordinator for the upgrade project, Katy Foraz and Cern’s UK communications manager Stephanie Hills, to one of the many access points to the LHC’s underground tunnels….
Read more at http://www.bbc.co.uk/news/science-environment-21941666

How the Large Hadron Collider is being repaired

Charged Black Hole Remnants at the LHC

black_holeG.L. Alberghi, L. Bellagamba, X. Calmet, R. Casadio, O. Micu
We investigate possible signatures of long-lived (or stable) charged black holes at the Large Hadron Collider. In particular, we find that black hole remnants are characterised by quite low speed. Due to this fact, the charged remnants could, in some cases, be very clearly distinguished from the background events, exploiting dE/dX measurements. We also compare the estimate energy released by such remnants with that of typical Standard Model particles, using the Bethe-Bloch formula….
Read more: http://arxiv.org/pdf/1303.3150v1.pdf

LHC to stir up hot particle soup before 2013 shut down

What happens when a proton smashes into a lead nucleus: a shower of particles through the CMS detector (Image: CERN)

What happens when a proton smashes into a lead nucleus: a shower of particles through the CMS detector (Image: CERN)

by Jacob Aron
At the foot of the misty mountains a mighty ring was forged – again! For one month, the Large Hadron Collider will smash two types of particles in a single magnetic ring.

So far, the LHC at CERN, near Geneva, Switzerland, has been colliding beams of identical types of particles, which are spun around the ring by a strong magnetic field. But starting in the third week of January it will smash protons into lead ions, in the hope of learning more about quark-gluon plasma. This is a hot soup of particles thought to make up the early universe.

Protons and lead ions have different masses and charges, so other colliders have used two magnetic rings to guide the beams. In the LHC, the beams will run in the same ring at slightly different speeds. “Nobody has ever run a collider quite like this before,” says CERN’s John Jowett.

Colour glass

Both beams circulate the LHC about 660,000 times a minute, but the proton beam goes slightly faster than the ion beam. “It’s as if you had a racetrack with a cyclist and a runner who have to bump into each other thousands of times at exactly four points,” says Paolo Giubellino of the ALICE experiment at CERN.

A successful test run last year has already thrown up surprises, including hints of a new form of matter known as colour-glass condensate. “It is an unexplained and very surprising feature and we very much wish to get more data to interpret it,” says Giubellino.

More data could help confirm the find, he says. The full-scale proton-lead ion runs will end in mid-February, when the collider shuts down for upgrades expected to last until late 2014


CERN’s LHC experiment ALICE, ITS Upgrade


ALICE New Silicon Tracker 3D Animation
This 3D animation, illustrates the design plans for the upgrade of the ALICE Inner Tracking System (ITS).The upgrade of the ITS will take place during the LHC long shutdown in 2017/18.

The ITS is the central most detector within ALICE, currently composed of three separate detectors (the Silicon Pixel Detector, the Silicon Drift Detector, and the Silicon Strip Detector) layered within two barrels around the LHC beam pipe.

This animation illustrates one of the design proposals for the upgraded ITS in three parts: firstly, the design of the CMOS sensor of the ITS silicon tracker and its assembly on carbon fibre staves; secondly, the assembly of the inner barrel; and thirdly, the assembly of the inner and outer barrels.

More about the ALICE detector:

LHC may have produced a previously undetected form of matter

Teams at the Large Hadron Collider must be developing a knack for producing tangible evidence of theoretical particles. After orchestrating 2 million collisions between lead nuclei and protons, like the sort you see above, the collider’s Compact Muon Solenoid group and researchers at MIT suspect that stray, linked pairs of gluon particles in the mix were signs of color-glass condensate, a currently theory-only form of matter that sees gluons travel in liquid-like, quantum-entangled waves. The clues aren’t definitive, but they were also caught unexpectedly as part of a more routine collision run; the team is curious enough that it’s looking for more evidence during weeks of similar tests in January. Any conclusive proof of the condensate would have an impact both on how we understand particle production in collisions as well as the ways gluons and quarks are arranged inside protons. If so, the CMS and MIT teams may well answer a raft of questions about subatomic physics while further justifying CERN’s giant underground rings.
Read more: www.engadget.com