Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


VELO – in you go! LHCb installs its precision silicon detector

One of the most fragile detectors for the Large Hadron Collider beauty (LHCb) experiment has been successfully installed in its final position. LHCb is one of four large experiments at CERN’s Large Hadron Collider (LHC), expected to start up in 2008.

For the LHCb collaboration, including UK scientists from the Universities of Liverpool and Glasgow, installing the Vertex Locator (VELO) detector into its final location in the underground experimental cavern at CERN has been a challenging task.

“It was a very delicate operation”, said Paula Collins, LHCb-VELO project leader, “With its successful completion, the VELO is now in place and ready for physics.”

Professor Themis Bowcock, lead LHCb scientist from the University of Liverpool where the intricate instrumentation was built and assembled said, “This is a big milestone for VELO and marks an end to the construction side of the project. With each one of the 42 modules that make up the instrument taking 1,000 hours to construct the final installation was a nail biting experience.”

The VELO is a precise particle-tracking detector that surrounds the proton-proton collision point inside the LHCb experiment. At its heart are 84 half-moon shaped silicon sensors, each one connected to its electronics via a delicate system of more than 5000 bond wires. These sensors will be located very close to the collision point, where they will play a crucial role in detecting b quarks, to help in understanding tiny but crucial differences in the behaviour of matter and antimatter.

The sensors are grouped in pairs to make a total of 42 modules, arranged in two halves around the beam line in the VELO vacuum tank. An aluminum sheet just 0.3 mm thick provides a shield between the silicon modules and the primary beam vacuum, with no more than 1 mm of leeway to the silicon modules. Custom-made bellows enable the VELO to retract from its normal position of just 5 mm from the beam line, to a distance 35 mm. This flexibility is crucial during the commissioning of the beam as it travels round the 27-km ring of the LHC.

“The installation was very tricky, because we were sliding the VELO blindly in the detector,” said Eddy Jans, VELO installation coordinator. “As these modules are so fragile, we could have damaged them all and not realized it straight away.” However, the verification procedures carried out on the silicon modules after installation indicated that no damage had occurred.

Dr Chris Parkes, scientist from the University of Glasgow LHCb team, who were responsible for testing the modules, adds, “Now that the VELO is in place we can start work on testing the instrument in situ in the lead up to science operations next year.”

UK scientists have a major involvement with the Vertex Locator. The individual modules were designed and assembled at Liverpool University and scientists from Glasgow University are responsible for the reception and testing of modules at CERN. NIKHEF provided the special foil that interfaces with the LHC vacuum. Other collaborators are EPFL Lausanne, CERN, Syracuse and MPI Heidelberg.

Gill Ormrod – Science and Technology Facilities Council Press Office
Tel: +44 (0) 1793 442012.
Mobile: +44 (0) 781 8013509
CERN Press Office
Tel: +44 22 7672141
Email :
Kate Spark – University of Liverpool Press Office
Tel: +44 (0) 151 794 2247
Martin Shannon - University of Glasgow Press Office
Tel: +44 (0) 141 330 8593
UK Science Contacts
Professor Themis Bowcock – Lead LHCb scientist at the University of Liverpool
Tel: +44 (0) 151 794 3315
Dr Tara Shears – LHCb scientist, University of Liverpool
Tel: +44 (0) 151 7943315
Dr Chris Parkes – LHCb scientist, University of Glasgow
Tel: +44 (0) 141 330 5885

Gill Ormrod | alfa
Further information:

More articles from Physics and Astronomy:

nachricht Scientists discover particles similar to Majorana fermions
25.10.2016 | Chinese Academy of Sciences Headquarters

nachricht Light-driven atomic rotations excite magnetic waves
24.10.2016 | Max-Planck-Institut für Struktur und Dynamik der Materie

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>