UK News from CERN Issue 72

 

Issue 72 contents

3D image

TIGRE cuts X-ray dose

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The early results offer potentially significant patient benefits.

Vacuum Photoriode

Solving a sticky problem

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There’s a popular misconception that CERN is all about physics. It is. And it’s not.

Summer Science Exhibition 2016: Antimatter Matters

Antimatter Matters at the Royal Society

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If matter and antimatter were created in equal amounts at the Big Bang, why do we live in a Universe dominated by matter?

Oxford nanoSystems’ surface coating

Tapping into technology

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The route to new physics is paved with new technologies.

Trophy

Relatively Special prize

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A team of UK school students will be putting Einstein’s Special Theory of Relativity to the test.


 

TIGRE cuts X-ray dose

3D image

Taken from the projection data, the 3d image has been reconstructed using the OS-SART algorithm
(Credit: Bath/CERN/Ander Biguri)

 

The University of Bath and CERN have created a toolbox for fast, accurate 3d X-ray image reconstruction. It’s part of a wider collaboration to apply tomography techniques developed at CERN to medical imaging (see UKNFC49), and the early results offer potentially significant patient benefits.

‘Tried and tested’ may be a comforting mantra, but step changes in medical diagnostics and treatment require clinicians to embrace new technology and new ideas. Still, it comes as some surprise that the vast majority of X-ray image reconstruction in hospitals is based on one type of scanning process - Cone Beam Computed Tomography (CBCT). The scanners work by taking a series of 2d projections of X-ray transparency through the patient and processing them into a 3d image. CBCT image reconstruction is a wide field with some 300 papers published every year featuring the benefits of new or improved imaging algorithms. Despite all this, a single algorithm completely dominates clinical imaging in hospitals.

As part of the collaborative project, Bath PhD student, Ander Biguri has reviewed a broad range of published CT algorithms and adapted them to run on a laptop fitted with a GPU (a graphical processor unit – the technology that you’d find inside an Xbox or Playstation).

In itself, this is not revolutionary – GPUs are perfectly suited to image processing – but building such a broad spectrum of GPU-based algorithms into a MATLAB/CUDA toolbox is. Not only can 3d images be processed around 1000 times faster, but using a high-level language like MATLAB for the overarching framework also means that it becomes trivial to compare reconstructions of the same data using different algorithms, or even to add new algorithms to the toolbox.

“Things that took days to process can be done in minutes on the laptop,” explains Steve Hancock (CERN). “But it isn’t just about raw speed. Using some of the other algorithms we can make an image to match the quality of current CT scanners but with fewer projections as input, and that means that we can potentially reduce the patient’s radiation dose by a factor of 10.”

Bearing in mind that the project’s total spend on GPU technology was £1K, the toolbox offers a very simple and affordable way to improve imaging and reduce radiation doses. And it’s just been made available as open source technology.

Called the Tomographic Iterative GPU-based Reconstruction (TIGRE) Toolbox, Steve hopes the open source approach will create a meeting point for academics and clinicians that will lead to the technology being adopted more widely. “Patients would immediately benefit if we could gently nudge clinicians away from their one favourite algorithm”, says Steve.

But in the wider project, Steve regards this development as “step zero”.

The next step is to incorporate motion compensation to take into account how internal organs move within the patient’s body as they breathe during the scan. And that’s where Phase Space Tomography, a technique first developed for imaging bunches of protons in CERN’s PS accelerator, comes in.

“We’re confident we can apply the methodology of Phase Space Tomography in a generic fashion to every algorithm in the toolbox,” says Steve, “but we need people to contribute motion models for us to test. Collaborative effort is essential.”

If Steve and the team succeed, this will take patient imaging into a new league. “Motion models are very complex, but we think that even the most basic models will improve current imaging.”

And there’s even potential for the technique to improve proton beam therapy. As the patient breathes, their tumour becomes a moving target for the proton beam. Steve believes that motion compensated tomography could be used in real time to steer the proton beam so that it follows the tumour. “I accept that this is years away, and depends on the clinical community adopting and developing a new technique, but I’m convinced the potential is there.”

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Solving a sticky problem

Vacuum Photoriode

Modelling a segmented dynode Vacuum Photoriode
(Credit: CMS / Sema Zahid)

 

There’s a popular misconception that CERN is all about physics. It is. And it’s not. Extending our knowledge of physics relies on exceptional engineering.

“There are so many opportunities for engineers at CERN”, says electronic and electrical engineering PhD student Sema Zahid (Brunel and CMS).

The chance to work at CERN is a dream come true for Sema. Her interest was first sparked by her school physics teacher, “he had a background in accelerator physics, and lots of enthusiasm,” she explains. A trip to CERN during the second year of her electronics and electrical engineering degree at Brunel only served to turn an interest into a passion.

Now based at CERN, Sema is contributing to two UK-led projects for CMS, one of which is working on upgrading the detector for the next long shutdown in 2024 by improving the signal collection from the detector. Sema’s using 3-d graphics modelling to look at the performance of the Vacuum Phototriodes (VPT) sensor in the ECAL detector with a view to developing a new type of VPT that could be used on CMS or future high energy physics experiments. These sensors take light generated by charged particles created in the collisions and turn it into an electrical signal which can be recorded.

She’s also part of a collaboration between Brunel, Bristol and RAL that’s addressing a sticky issue; CMS uses more than 140,000 Avalanche Photodiodes (APDs) and the epoxy glue that fixes the APDs to the scintillating crystals in the detector is sometimes the source of recoil protons from the neutron background. These protons can cause large, anomalous, and unwanted signals in the APDs. Until now, removing the unwanted signals has been managed by existing, but limited, electronics on the detector. The team is aiming to find an improved solution for the future.

When the LHC is upgraded to provide higher luminosity beams, there will be more overlapping collisions and there’s a risk that the unwanted signals will be no longer be able to be removed efficiently – the team needs to find a solution. As Sema explains, it’s a big problem, “At the moment, there are 40 million proton bunch crossings per second. CMS detector hardware filters these to provide 100 000 events per second. A second layer of filtering reduces this further to 300 events per second for storage. These figures will be higher in the future.”

A passionate advocate for getting more women into engineering, the project encapsulates the essence of engineering for Sema “it has everything; theory, practice, challenges and problem solving. I’m not just sat at a desk – I get to do practical experiments!”

Sema is undecided whether she will look for a post doc position in academia, or move into industry when she completes her PhD. In the meantime, she’s clearly enjoying contributing to CMS, and gaining skills and expertise that will be invaluable wherever she decides to go next.

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Antimatter Matters at the Royal Society

Summer Science Exhibition 2016: Antimatter Matters
(Credit: The Royal Society)

 

It’s one of the biggest challenges in physics; if matter and antimatter were created in equal amounts at the Big Bang, why do we live in a Universe dominated by matter? The UK teams on two CERN experiments that are trying to get to the bottom of this mystery will be showcasing their research at the prestigious Royal Society Summer Science Exhibition.

“I felt that an exhibit spanning a range of research and applications on antimatter would make for an interesting way of presenting the work”, says Chris Parkes (Manchester and LHCb). “It’s also significantly different from previous high energy physics exhibits at the Royal Society. We hope it will widen the public’s knowledge of antimatter.”

It’s not just the public’s knowledge that will have increased as a result of the exhibition. It’s the first time that the LHCb and ALPHA experiments have collaborated; 12 UK institutes and 50 people have developed material for the stand, demonstrations, brochures, a video and a web site. There will be teams of six researchers manning the stand throughout the exhibition, and this has meant getting up to speed with each other’s experiments.

“Even if both experiments work on antimatter, the approaches are very, very different, in terms of the sort of physics we can get out, and how we go about doing the experiments,” says Niels Madsen (Swansea and ALPHA).

“The people involved in Antimatter Matters will certainly gain a much broader picture of where their research fits in the overall physics landscape and will use this opportunity to build new bridges between the, normally, quite separate LHCb and ALPHA communities through a shared common goal. In particular, the younger participants can use this to open their eyes and improve their understanding how antimatter can be studied. I think this can be of great value to the community. In fact, I’d say, this is the start of being an antimatter community.”

The Royal Society Summer Science Exhibition runs from 4-10 July.

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Tapping into technology

Oxford nanoSystems’ surface coating

Oxford nanoSystems’ surface coating has demonstrated a 520% enhancement in the heat transfer coefficient compared to a bare surface
(Credit: Oxford nanoSystems)

 

The route to new physics is paved with new technologies. CERN’s network of Business Incubation Centres (the first of which is thriving in the UK) aims to exploit this IP by finding new applications outside physics.

The Business Incubation Centres (BICs) help entrepreneurs and small tech businesses take innovative ideas based on IP developed for CERN experiments from technical concept to market reality. They provide office-space, expertise, business support, access to local and international networks and help with finding further funding.

This combination of practical and technical support has helped Oxford nanoSystems (OnS) develop nanostructured coatings which could dramatically cut costs for businesses in a range of sectors. The company is the first graduate from the STFC CERN Business Incubation Centre.

OnS specialises in heat transfer technology and its innovative nanostructured coating improves heat transfer rates by more than four times, and therefore reduces the energy required to heat or cool a system. Less energy means lower costs and environmental benefits, and OnS is targeting the transportation, HVAC/refrigeration, energy, and electronics sectors.

“Having access to CERN staff and facilities through the CERN BIC grant allowed us to increase our ability to examine how our coatings work in a system, explains CEO Alexander Reip. “These kinds of measurements are hard for a small company to get hold of easily so having this access was a great help. The 40 hours of STFC time meant we could use a world class thermodynamicist to advise us in interpreting the data we got back to make quick modifications to our technology. We also couldn’t have done any of this without the facilities and equipment of STFC at Harwell. The state-of-the-art labs and microscopy equipment lets us very quickly create and analyse different structures at low cost which a company of our size could never do on a small budget.”

The company is now working on the next funding round and looking into development of a large scale production plant for its coating process.

Meanwhile, Camstech is the latest recruit to the BIC. Its vision is to commercialise a novel electrochemical sensor technology initially developed for life sciences research into biotechnology and medical diagnostics.

In 2015, the company identified detector technology originally developed for CMS that would enable it to scale up and manufacture its sensors more cost effectively.

"We are very excited to be part of the CERN BIC”, says Camstech founder, Pankaj Vadgama. “Not only does it help the company to overcome the challenge of sensor manufacture, but it also provides access to the tremendous intellectual potential, skills and expertise of scientists across the CERN, Rutherford Appleton and Daresbury Laboratories. We see the CERN BIC as a springboard that will allow Camstech Ltd to take a big leap towards the market."

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Relatively Special prize

Trophy

(Credit: Michael D Brown / Shutterstock)

 

A team of UK school students will be putting Einstein’s Special Theory of Relativity to the test as joint winners in CERN’s Beamline for Schools competition.

Relatively Special, the team from Colchester Royal Grammar School (CRGS), will travel to CERN in September to carry out their own experiment using a CERN accelerator beam. In keeping with CERN’s international approach to science, Relatively Special will be working with Pyramid Hunters, a team of high school students from Poland.

151 teams from 37 countries took part in the competition enables high-school students to run an experiment on a fully equipped CERN beamline, in the same way that researchers do at the Large Hadron Collider and other CERN facilities. Students were asked to submit a written proposal and video explaining why they wanted to come to CERN, what they hoped to take away from the experience and initial thoughts of how they would use the particle beam for their experiment.

CERN scientists and experts then evaluated the proposals based on creativity, motivation, feasibility and scientific method. A final selection was put forward to the CERN scientific committee responsible for assigning beam time to experiments, who chose the two winning teams.

“It is a tremendous initiative,” says CRGS Head of Physics and Team Coach, Kevin Harvey, “the excitement it is generating here is going to have a very long half-life. We all consider it an honour to be involved with such a great and prestigious organisation.”

Relatively Special plans to test the validity of the Lorentz factor by measuring the effect of time dilation due to Special Relativity on the decay rate of pions, and UK News from CERN will be on hand to meet the team and see how they get on.

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