From Symmetry: “Linear collider focus gets down to size”

In a display of timing worthy of a blockbuster movie, a multinational team of accelerator physicists focused a beam of electrons down to the tiny size needed for a future linear collider the same week that the linear collider board formed.

March 11, 2013
Lori Ann White

“In late 2012, Toshiaki Tauchi clicked the send button on an email with the subject line ’70nm achieved at ATF2!’ It signaled a major success for Tauchi, an accelerator physicist at KEK, and his colleagues at the Japanese lab’s Accelerator Test Facility 2: They had shown they could focus a beam of electrons down to the tiny size required by a future linear collider.

Photo: Nobu Toge, KEK

Tauchi is a member of the executive committee overseeing the global design effort for the International Linear Collider, and the timing of his announcement could not have been better.

Just the day before, Fermilab Director Pier Oddone, in his role as chair of the International Committee for Future Accelerators, announced the formation of a Linear Collider Board to shepherd the global effort to build a linear collider capable of pushing back the frontiers of high-energy physics revealed by the Large Hadron Collider at CERN. With Japan expressing interest in hosting such a facility and the even more recent formation of a Linear Collider Collaboration to coordinate and advance global plans, momentum seems to be building for the construction of the giant electron-positron collider.”

See the full article here.

Symmetry is a joint Fermilab/SLAC publication.

From ilc newsline: “Superconducting radio-frequency”

9 August 2012
Daisy Yuhas

“How do you accelerate particles in a particle collider? One answer is superconducting radio-frequency (SCRF) cavities. To give particles energy as they move through an accelerator, physicists use cavities containing electric fields that oscillate. The changes in electric field help push the particles from one cavity to the next. These oscillations occur with the same frequency as radio waves, which is why this form of acceleration is called radio-frequency.

Image: Rey.Hori

Superconducting refers to the way in which electric current is carried through these accelerating cavities. Electric current in a cavity may create friction—unless the cavity is created using special metals called superconductors. ‘Some metals have no resistance below a critical temperature,’ says Fermilab scientist Camille Ginsburg. This means that these metals conduct electricity perfectly. Even in a superconductor, if electric current passing through a cavity encounters any bumps or impurities, the flow of electricity is interrupted and energy can be lost as heat. This is why cavities must be very clean and polished to a smooth finish. In proposed accelerators such as the ILC, the metal used is niobium, which becomes superconducting at temperatures below 9.2 Kelvin (-264°C). Keeping cool isn’t easy, however. To do this, each cavity is kept in a large thermos structure holding frigid liquid helium, typically at 2 Kelvin (-271°C).”

See the full post here.

From ILC Newsline: “Doing the cryomodule shuffle”

ilc – International Linear Collider

Leah Hesla
19 April 2012

“Fermilab researchers will soon take a quantum step towards the realisation of an ILC-type cryomodule.

Next week the newly assembled cryomodule RFCA002, familiarly referred to as CM2, will replace CM1 in the Advanced Superconducting Test Accelerator at the laboratory’s NML test facility. The change-out is a rung up on the R&D ladder, and not only because it is the second eight-cavity cryomodule to come out of the laboratory. Far more than the first, CM2 resembles an ILC-type cryomodule in its components and cavity test performance.

‘The hope for CM2 is that it will be the first cryomodule to reach the average ILC specification gradient at Fermilab,” said lead engineer Tug Arkan. The so-called S1 goal of the ILC programme is to achieve an average gradient of 31.5 megavolts per metre over eight metre-long cavities. “That’s the goal to demonstrate. We haven’t yet proved it at Fermilab.’”

Cryomodule 2 in the Fermilab Industrial Center Building. Image: Reidar Hahn

See the full article here.

From Symmetry/Breaking: “Two proposed linear collider programs to be joined under new governance”

Leah Hesla
April 11, 2012

“The world’s two most mature proposals for a collider complementary to the Large Hadron Collider are joining collaborative forces.

The two proposed electron-positron collider projects, the Compact Linear Collider Study and the International Linear Collider, have traditionally been viewed as casual rivals–both in the running to be built as the future complement to CERN’s proton-smashing machine, the LHC.

Now CLIC and the ILC are joining organizational forces under the linear collider umbrella. The new organizational structure, announced in February by the International Committee for Future Accelerators (ICFA) Chair Pier Oddone [Director of Fermilab], is still in its very early stages, but those involved hope to finalize the governance framework by July, implementing the new plan gradually over the following year. The plan is for ICFA, which currently oversees the ILC Global Design Effort, to establish a Linear Collider Board, which would in turn govern CLIC, the ILC, and a third program that focuses on detector research for both machines.

The CLIC and the ILC programs are joining organizational forces within the framework of the International Committee for Future Accelerators. ICFA plans to establish a Linear Collider Board.

‘As we move into the next phase in the evolution of linear colliders it is important to bring the ILC and CLIC efforts under unified leadership,’ Oddone said.”

Symmetrybreaking is a joint Fermilab/SLAC publication

From ilc newsline: “LCIO 2.0 improves simulation coordination’

Leah Hesla
8 December 2011

“The data model that transformed the linear collider detector community from a computational Tower of Babel into a group that inputs with one voice has gotten an update.

ILC software developers released LCIO. 2.0 this autumn. The new version of LCIO, a particle event data model, includes features that help scientists cope with the increasingly sophisticated data being fed into particle event simulations.

‘We considerably improved the data model – in particular for the description of charged particle tracks – and put in little things from users’ requests or features we thought would improve physicists’ lives,’ said DESY’s Frank Gaede, one of the main developers of LCIO and coordinator of ILCSoft, one of two software packages for which LCIO is the core.”

Illustration of the way LCIO works with multiple software formats. Image: DESY

A t t event simulated and reconstructed using ILCSoft, one of two software programs with LCIO at its core. Image: DESY

See the full article here.

From ILC Newsline: Several Interesting and Important Articles

Today’s news release is here.

Here are the links and some images to stimulate your curiosity.

Light As A Feather
Perrine Royole-Degieux

“A group of European physicists, the PLUME collaboration, aims to prototype an ultra-light device intended to equip one of the thinnest and lightest elements at the inner heart of the ILC detectors: the vertex detector. At CERN one month ago, a full-scale prototype equipped with CMOS pixel sensors was successfully tested in beam.”

See this full article here.

LCIO 2.0 improves simulation coordination

Leah Hesla
“Over the years, the linear collider input/output event data model has facilitated data sharing between the world’s linear collider detector groups
A new version of linear collider data storage software was released this past autumn to accommodate detector scientists’ increasing sophistication in simulating particle events. LCIO (the name comes from ‘linear collider input/output’) continues to facilitate agreement among the world’s linear collider groups with a common event data model and file format for data exchange.”

See this full article here.

Pondering the future of particle physics

Barry Barish

“The International Committee for Future Accelerators (ICFA) sponsors a meeting every three years on Future Perspectives in High Energy Physics. This year the ICFA seminar was held at CERN and it broadly covered plans and ideas for future facilities for our field. This meeting was particularly timely, as it coincided both with the completion of the impressive first year of running of the LHC and with the kickoff of the update of the European Strategy for Particle Physics to be completed in 2013.”

See this full article here.

From CERN Bulletin via ILC Newsline: “Detectors on the drawing board”

Katarina Anthony
Monday 24 October 2011

” ‘While the LHC experiments remain the pinnacle of detector technology, you may be surprised to realise that the design and expertise behind them is well over 10 years old,’ says Lucie Linssen, CERN’s Linear Collider Detector (LCD) project manager whose group is pushing the envelope of detector design. “The next generation of detectors will have to surpass the achievements of the LHC experiments. It’s not an easy task but, by observing detectors currently in operation and exploiting a decade’s worth of technological advancements, we’ve made meaningful progress.”

The LCD team is currently working on detectors for the CLIC experiment. “Electron-positron colliders like CLIC demand detectors with significantly more precision than those at the LHC,” explains Lucie. “We’ve studied a variety of techniques to cope with this precision and other CLIC-specific issues. Many of these were pioneered for earlier linear colliders, but have since been adapted to fit CLIC’s unique parameters.” The team’s work has culminated in two detector designs, published in the CLIC Conceptual Design Report.

A simulated event display in one of the new generation detectors.

There is a lot of interesting information in this post. See the full article here. This article at ILC newsline is a bit of a surprise to me, as the CLIC is in direct competition with the ILC itself for future funding ans use.

From ilc newsline: “CERN balances linear collider studies”

[What did that guy in L.A., Rodney King, say? "Can't we all get along?"]

“The forces behind the two most mature proposals for a next-generation collider, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC) study , have been steadily coming together, with scientists from both communities sharing ideas and information across the technology divide. In at least nominal support of cooperation between the two, CERN in Switzerland, where most CLIC research takes place, recently converted the project-specific position of CLIC Study Leader to the concept-based Linear Collider Study Leader.

Though not very much involved with superconducting radiofrequency (SRF) technology, where ILC researchers have made significant advances, CERN participates in many aspects of ILC-related studies through combined working groups, site studies and detector and physics activities.

The second conference held jointly by ILC and CLIC collaborations was held this year in Granada, Spain.

See the full article here.

From ilc Newsline: “Going with the particle flow”

The particle flow algorithm joins smart programming with the high granularity of next-generation particle detectors to measure energies with unprecedented resolution

Leah Hesla
15 September 2011

“The familiar image of a collision event in a particle detector is a beautiful mess: Gossamer lines shoot and spiral every which way from a common point, revealing the paths of the post-collision projectiles. Unfortunately for particle tagging, the tracks almost always end in knotty energy clusters, leading physicists down trails that stop abruptly, unresolved, with a splat.

Particle tracks inside a detector. Image courtesy of John Marshall

Matching each track to the right splat in the detector is the aim of the particle flow algorithm paradigm, or PFA, which is being developed for linear collider-type detectors. PFA helps scientists disentangle a collision’s energy deposits by dialing up the detector’s spatial resolution, bringing particle tracks into clearer focus. Simulations show that the method can resolve particle energies two to three times better than can current procedures.

PandoraPFA cone-based forward projective clustering. Image courtesy of John Marshall

‘It’s a real tour de force to be able to measure an event with that kind of precision,’ said SLAC’s Norman Graf, who leads the American Linear Collider Physics and Detector Simulations Working Group.

To achieve the kind of precision that would make PFA viable, scientists pushed at the traditional functional limits of the detector’s calorimeter.

PandoraPFA topological reconstruction based on proximity (left) and direction of track segment (right). Image courtesy of John Marshall

‘The idea of particle flow is to do something completely different,’ said University of Cambridge’s Mark Thomson, convener of the ILD Detector Concept Analysis Working Group. ‘Effectively the idea is to measure as little energy as possible in the calorimeter and measure as much as possible and very precisely from the tracking chambers.’ Tracking chambers, or trackers, show the initial path of a post-collision particle; calorimeters measure energy.”

See the full article here.

From ILC newsline: “Extending the energy reach of the ILC”

Barry Barish
11 August 2011

“The GDE design for the ILC as presented in the Reference Design Report (RDR) is for an electron-positron colliding beam facility having a maximum centre-of-mass energy of 500 gigaelectronvolts (GeV). No design or upgrade path to 1 teraelectronvolt (TeV) was presented in the RDR. However, the option to upgrade to higher energies was explicitly maintained in the reference design by ensuring that the beam delivery system could be upgraded, beam dumps were sufficient for higher energy and other considerations. Now, having had significant success achieving high gradients for the baseline machine and anticipating results that will guide the choice of energy from the LHC, we are undertaking a study of paths towards higher energy for the Technical Design Report (TDR) and are considering an R&D focus towards cost-effectively reaching higher energy for the post-TDR programme.

TeV upgrade scheme, as outlined by GDE Project Manager Nick Walker (DESY)

See the full and very interesting article here.