LHC Dipoles Accelerate

CERN Multimedia

2001-01-01

Andrezej Siemko (left), Peter Sievers (centre), and Lucio Rossi (right), have the exciting challenge of preparing and testing 2000 magnets for the LHC. The LHC is going to require a lot of powerful magnets by the time it begins operation in 2006. More specifically, it is going to need 130 special magnets, 400 quadrupoles, and a whopping 1250 dipoles! Preparing and testing these magnets for the conditions they will encounter in the LHC is not an easy task. But evaluation of the most recently received magnet, from the German company Noell, is showing that while the monumental task of receiving and testing nearly 2000 magnets is going to be exhausting, the goals are definitely attainable. At the moment and over the next year, pre-series magnets (the magnets that CERN uses to fine tune performance) are arriving slowly (90 in total will arrive), but by 2003 the rate of series magnet arrival will accelerate to 9 per week, that's over 450 in a single year! And working with these magnets when they arrive is tough. ...

Demonstration of the LHC Safety Training Tunnel Mock-Up

CERN Multimedia

Brice, Maximilien

2014-01-01

Members of CERN's management visit the LHC tunnel mock-up at the Safety Training Centre on the Prévessin site. The facility is used to train personnel in emergency responses including the use of masks and safe evacuation.

LHC Accelerator Fault Tracker - First Experience

CERN Document Server

Apollonio, Andrea; Roderick, Chris; Schmidt, Ruediger; Todd, Benjamin; Wollmann, Daniel

2016-01-01

Availability is one of the key performance indicators of LHC operation, being directly correlated with integrated luminosity production. An effective tool for availability tracking is a necessity to ensure a coherent capture of fault information and relevant dependencies on operational modes and beam parameters. At the beginning of LHC Run 2 in 2015, the Accelerator Fault Tracking (AFT) tool was deployed at CERN to track faults or events affecting LHC operation. Information derived from the AFT is crucial for the identification of areas to improve LHC availability, and hence LHC physics production. For the 2015 run, the AFT has been used by members of the CERN Availability Working Group, LHC Machine coordinators and equipment owners to identify the main contributors to downtime and to understand the evolution of LHC availability throughout the year. In this paper the 2015 experience with the AFT for availability tracking is summarised and an overview of the first results as well as an outlook to future develo...

Remotely Operated Train for Inspection and Measurement in CERN's LHC Tunnel

CERN Document Server

Kershaw, K; Bestmann, P; Feniet, T; Forkel-Wirth, D; Grenard, J L; Rousset, N

2010-01-01

Personnel access to the LHC tunnel will be restricted to varying extents during the life of the machine due to radiation and cryogenic hazards. For this reason a remotely operated modular inspection train, (TIM) running on the LHC tunnel’s overhead monorail has been developed. In order to be compatible with the LHC personnel access system, a small section train that can pass through small openings at the top of sector doors has now been produced. The basic train can be used for remote visual inspection; additional modules give the capability of carrying out remote measurement of radiation levels, environmental conditions around the tunnel, and even remote measurement of the precise position of machine elements such as collimators. The paper outlines the design, development and operation of the equipment including preparation of the infrastructure. Key features of the trains are described along with future developments and intervention scenarios.

LHC: Collisions on course for 2007

CERN Document Server

2006-01-01

In the LHC tunnel and caverns, a particle accelerator and detectors are rapidly taking shape. At last week's Council meeting, delegates took stock of the year's progress towards first collisions in 2007.

Biocell Training course mandatory for accessing the LHC tunnel from 1 December 2010

CERN Multimedia

CERN Bulletin

2010-01-01

Following the incident in Sector 3-4 on 19 September 2008, which led to a major helium release in the LHC tunnel, measures have been put in place to reinforce safety awareness and training for all those accessing the tunnel.   One of the actions taken was to create a hands-on safety course on how to put the Self Rescue Breathing Apparatus (Biocell) on. The course is entitled “Biocell Training” and started late summer 2009. To date some 1350 people have been trained, although roughly 1700 people have access to the LHC machine tunnel. With the training capacity in place, it is feasible to train everyone with access before the coming Christmas technical stop, which will start in December 2010. The “Biocell Training” course has clearly shown the necessity of training the personnel. In addition, the feedback from the participants is very positive. Decision In the light of the conclusion reached by HSE, DSOs and the GLIMOS of the LHC experiments, successful comple...

Remote Inspection, Measurement and Handling for LHC

CERN Document Server

Kershaw, K; Coin, A; Delsaux, F; Feniet, T; Grenard, J L; Valbuena, R

2007-01-01

Personnel access to the LHC tunnel will be restricted to varying extents during the life of the machine due to radiation, cryogenic and pressure hazards. The ability to carry out visual inspection, measurement and handling activities remotely during periods when the LHC tunnel is potentially hazardous offers advantages in terms of safety, accelerator down time, and costs. The first applications identified were remote measurement of radiation levels at the start of shut-down, remote geometrical survey measurements in the collimation regions, and remote visual inspection during pressure testing and initial machine cool-down. In addition, for remote handling operations, it will be necessary to be able to transmit several real-time video images from the tunnel to the control room. The paper describes the design, development and use of a remotely controlled vehicle to demonstrate the feasibility of meeting the above requirements in the LHC tunnel. Design choices are explained along with operating experience to-dat...

Tunnel flexibility effect on the ground surface acceleration response

Science.gov (United States)

Baziar, Mohammad Hassan; Moghadam, Masoud Rabeti; Choo, Yun Wook; Kim, Dong-Soo

2016-09-01

Flexibility of underground structures relative to the surrounding medium, referred to as the flexibility ratio, is an important factor that influences their dynamic interaction. This study investigates the flexibility effect of a box-shaped subway tunnel, resting directly on bedrock, on the ground surface acceleration response using a numerical model verified against dynamic centrifuge test results. A comparison of the ground surface acceleration response for tunnel models with different flexibility ratios revealed that the tunnels with different flexibility ratios influence the acceleration response at the ground surface in different ways. Tunnels with lower flexibility ratios have higher acceleration responses at short periods, whereas tunnels with higher flexibility ratios have higher acceleration responses at longer periods. The effect of the flexibility ratio on ground surface acceleration is more prominent in the high range of frequencies. Furthermore, as the flexibility ratio of the tunnel system increases, the acceleration response moves away from the free field response and shifts towards the longer periods. Therefore, the flexibility ratio of the underground tunnels influences the peak ground acceleration (PGA) at the ground surface, and may need to be considered in the seismic zonation of urban areas.

Post-LHC accelerator magnets

International Nuclear Information System (INIS)

Gourlay, Stephen A.

2001-01-01

The design and practicality of future accelerators, such as hadron colliders and neutrino factories being considered to supercede the LHC, will depend greatly on the choice of superconducting magnets. Various possibilities will be reviewed and discussed, taking into account recent progress and projected improvements in magnet design and conductor development along with the recommendations from the 2001 Snowmass workshop

Baseline review of the U.S. LHC Accelerator project

International Nuclear Information System (INIS)

1998-02-01

The Department of Energy (DOE) Review of the U.S. Large Hadron Collider (LHC) Accelerator project was conducted February 23--26, 1998, at the request of Dr. John R. O'Fallon, Director, Division of High Energy Physics, Office of Energy Research, U.S. DOE. This is the first review of the U.S. LHC Accelerator project. Overall, the Committee found that the U.S. LHC Accelerator project effort is off to a good start and that the proposed scope is very conservative for the funding available. The Committee recommends that the project be initially baselined at a total cost of $110 million, with a scheduled completion data of 2005. The U.S. LHC Accelerator project will supply high technology superconducting magnets for the interaction regions (IRs) and the radio frequency (rf) straight section of the LHC intersecting storage rings. In addition, the project provides the cryogenic support interface boxes to service the magnets and radiation absorbers to protect the IR dipoles and the inner triplet quadrupoles. US scientists will provide support in analyzing some of the detailed aspects of accelerator physics in the two rings. The three laboratories participating in this project are Brookhaven National Laboratory, Fermi National Accelerator Laboratory (Fermilab), and Lawrence Berkeley National Laboratory. The Committee was very impressed by the technical capabilities of the US LHC Accelerator project team. Cost estimates for each subsystem of the US LHC Accelerator project were presented to the Review Committee, with a total cost including contingency of $110 million (then year dollars). The cost estimates were deemed to be conservative. A re-examination of the funding profile, costs, and schedules on a centralized project basis should lead to an increased list of deliverables. The Committee concluded that the proposed scope of US deliverables to CERN can be readily accomplished with the $110 million total cost baseline for the project. The current deliverables should serve as

Electron accelerator for tunneling through hard rock

International Nuclear Information System (INIS)

Avery, R.T.; Keefe, D.

1975-10-01

Earlier work demonstrated that intense sub-microsecond bursts of energetic electrons cause significant pulverization and spalling of a variety of rock types. The spall debris generally consists of sand, dust, and small flakes. If carried out at rapid repetition rate, this can lead to a promising technique for increasing the speed and reducing the cost of underground excavation of tunnels, mines, and storage spaces. The conceptual design features of a Pulsed Electron Tunnel Excavator capable of tunneling approximately ten times faster than conventional drill/blast methods are presented, with primary emphasis on the electron accelerator and only a brief description of the tunneling aspects. Of several candidate types of accelerators, a linear induction accelerator producing electron pulses (5 MV, 5 kA, 1.0 μs = 25 kJ) at a 360 Hz rate was selected for the conceptual example. This provides the required average electron beam power output of 9 MW. The feasibility of such an accelerator is discussed

Electron accelerator for tunneling through hard rock

International Nuclear Information System (INIS)

Avery, R.T.; Keefe, D.

1975-01-01

Earlier work demonstrated that intense sub-microsecond bursts of energetic electrons cause significant pulverization and spalling of a variety of rock types. The spall debris generally consists of sand, dust, and small flakes. If carried out at rapid repetition rate, this can lead to a promising technique for increasing the speed and reducing the cost of underground excavation of tunnels, mines, and storage spaces. The conceptual design features of a Pulsed Electron Tunnel Excavator capable of tunneling approximately ten times faster than conventional drill/blast methods are presented with primary emphasis on the electron accelerator and only a brief description of the tunneling aspects. Of several candidate types of accelerators, a linear induction accelerator producing electron pulses (5 MV, 5 kA, 1.0 μs = 25 kJ) at a 360 Hz rate was selected for the conceptual example. This provides the required average electron beam power output of 9 MW. The feasibility of such an accelerator is discussed

A true-to-life fire alert in the LHC tunnel

CERN Multimedia

2008-01-01

Around 40 men from the fire brigades of CERN and the two Host States were put through their paces in an exercise with a scenario involving a fire between Points 6 and 7 of the LHC tunnel and the mysterious disappearance of a member of personnel.

Support for the LHC experiments

CERN Document Server

Butin, François; Gastal, M; Lacarrère, D; Macina, D; Perrot, A L; Tsesmelis, E; Wilhelmsson, M; CERN. Geneva. TS Department

2008-01-01

Experimental Area Teams have been put in place and charged with the general co-ordination and management of the LHC experimental areas and of the zones in the LHC tunnel hosting near-beam detectors of the experiments. This organization is responsible for the in situ co-ordination of work with the aim of providing a structure that enables the experiment collaborations and accelerator groups to carry out their work effectively and safely. This presentation will review some key elements in the support given to the LHC experimental areas and, given the track record and successful implementation during the LHC installation and commissioning phase, will argue that such an organization structure will be required also for the period of LHC exploitation for physics.

Final report on the Controlled Cold Helium Spill Test in the LHC tunnel at CERN

International Nuclear Information System (INIS)

Dufay-Chanat, L; Bremer, J; Casas-Cubillos, J; Koettig, T; Vauthier, N; Van Weelderen, R; Winkler, T; Chorowski, M; Grabowski, M; Jedrusyna, A; Lindell, G; Nonis, M

2015-01-01

The 27 km circumference LHC underground tunnel is a space in which the helium cooled LHC magnets are installed. The vacuum enclosures of the superconducting magnets are protected by over-pressure safety relief devices that open whenever cold helium escapes either from the magnet cold enclosure or from the helium supply headers, into this vacuum enclosure. A 3-m long no stay zone around these devices is defined based on scale model studies, protecting the personnel against cold burns or asphyxia caused by such a helium release event. Recently, several simulation studies have been carried out modelling the propagation of the helium/air mixture, resulting from the opening of such a safety device, along the tunnel. The released helium flows vary in the range between 1 kg/s and 0.1 kg/s. To validate these different simulation studies, real life mock-up tests have been performed inside the LHC tunnel, releasing helium flow rates of 1 kg/s, 0.3 kg/s and 0.1 kg/s. For each test, up to 1000 liters of liquid helium were released under standard operational tunnel conditions. The data recorded include oxygen concentration, temperature and flow speed measurements, and video footage used to assess qualitatively the visibility. These measurements have been made in the up- and downstream directions, with respect to the air ventilation flow, of the spill point.This paper presents the experimental set-up under which these release tests were made, the effects of these releases on the atmospheric tunnel condition as a function of the release flow rate. We discuss the modification to the personnel access conditions to the LHC tunnel that are presently implemented as a result of these tests. (paper)

Final report on the Controlled Cold Helium Spill Test in the LHC tunnel at CERN

Science.gov (United States)

Dufay-Chanat, L.; Bremer, J.; Casas-Cubillos, J.; Chorowski, M.; Grabowski, M.; Jedrusyna, A.; Lindell, G.; Nonis, M.; Koettig, T.; Vauthier, N.; van Weelderen, R.; Winkler, T.

2015-12-01

The 27 km circumference LHC underground tunnel is a space in which the helium cooled LHC magnets are installed. The vacuum enclosures of the superconducting magnets are protected by over-pressure safety relief devices that open whenever cold helium escapes either from the magnet cold enclosure or from the helium supply headers, into this vacuum enclosure. A 3-m long no stay zone around these devices is defined based on scale model studies, protecting the personnel against cold burns or asphyxia caused by such a helium release event. Recently, several simulation studies have been carried out modelling the propagation of the helium/air mixture, resulting from the opening of such a safety device, along the tunnel. The released helium flows vary in the range between 1 kg/s and 0.1 kg/s. To validate these different simulation studies, real life mock-up tests have been performed inside the LHC tunnel, releasing helium flow rates of 1 kg/s, 0.3 kg/s and 0.1 kg/s. For each test, up to 1000 liters of liquid helium were released under standard operational tunnel conditions. The data recorded include oxygen concentration, temperature and flow speed measurements, and video footage used to assess qualitatively the visibility. These measurements have been made in the up- and downstream directions, with respect to the air ventilation flow, of the spill point. This paper presents the experimental set-up under which these release tests were made, the effects of these releases on the atmospheric tunnel condition as a function of the release flow rate. We discuss the modification to the personnel access conditions to the LHC tunnel that are presently implemented as a result of these tests.

The surveyors get the measure of the LHC

CERN Multimedia

2002-01-01

The first to start work in the LHC tunnel, the surveyors are precisely marking out the positions of the future accelerator's magnets. A total of 7000 reference points will have to be marked out over two years.

CERN-LHC accelerator superconducting magnet. Development and international cooperation

International Nuclear Information System (INIS)

Yamamoto, Akira; Nakamoto, Tatsushi; Sasaki, Ken-ichi

2009-01-01

CERN-LHC accelerator superconducting magnets and a cooperative work for interaction region quadrupole magnets are introduced. The accelerator commissioning and the incident happened during the commissioning in 2008 is also briefly discussed. (author)

Final report on the Controlled Cold Helium Spill Test in the LHC tunnel at CERN

CERN Document Server

Dufay-Chanat, L; Casas-Cubillos, J; Chorowski, M; Grabowski, M; Jedrusyna, A; Lindell, G; Nonis, M; Koettig, T; Vauthier, N; van Weelderen, R; Winkler, T

2015-01-01

The 27 km circumference LHC underground tunnel is a space in which the helium cooled LHC magnets are installed. The vacuum enclosures of the superconducting magnets are protected by over-pressure safety relief devices that open whenever cold helium escapes either from the magnet cold enclosure or from the helium supply headers, into this vacuum enclosure. A 3-m long no stay zone around these devices is defined based on scale model studies, protecting the personnel against cold burns or asphyxia caused by such a helium release event. Recently, several simulation studies have been carried out modelling the propagation of the helium/air mixture, resulting from the opening of such a safety device, along the tunnel. The released helium flows vary in the range between 1 kg/s and 0.1 kg/s. To validate these different simulation studies, real life mock-up tests have been performed inside the LHC tunnel, releasing helium flow rates of 1 kg/s, 0.3 kg/s and 0.1 kg/s. For each test, up to 1000 liters of liquid helium wer...

LHC 2008 lectures
The LHC: an accelerator of science

CERN Multimedia

2008-01-01

In 2008, CERN will be switching on the greatest physics experiment ever undertaken. The Large Hadron Collider, or LHC, is a particle accelerator that will provide many answers to our questions about the Universe - What is the reason for mass? Where is the invisible matter in the Universe hiding? What is the relationship between matter and antimatter? Will we have to use a theory claiming more than four dimensions? … and what about "time" ? To understand better the raison d’être of the LHC, this gigantic, peerless scientific instrument and all the knowledge it can bring to us, members of the general public are invited to a series of lectures at the Globe of Science and Innovation. Thursday 8 May 2008 at 8.00 p.m. « Comment fonctionne l’Univers ? Ce que le LHC peut nous apprendre » Alvaro de Rujula, CERN physicist Thursday 15 May 2008 at 8.00 p.m. – « Une nouvelle vision du monde » Jean-Pierre Luminet, Director of...

Electromagnetic and mechanical design of a 56 mm aperture mode dipole for the LHC

International Nuclear Information System (INIS)

Ahlbaeck, J.; Ikaeheimo, J.; Jaervi, J.

1994-01-01

The Large Hadron Collider (LHC) project is proposed as the future extension of the CERN accelerator complex. The LHC requires twin aperture superconducting dipoles of highest possible field to guide the proton beams in the existing LEP tunnel of 26.7 km circumference. This paper describes the electromagnetic and mechanical design of a 56 mm aperture model dipole for the LHC

Run II of the LHC: The Accelerator Science

Science.gov (United States)

Redaelli, Stefano

2015-04-01

In 2015 the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) starts its Run II operation. After the successful Run I at 3.5 TeV and 4 TeV in the 2010-2013 period, a first long shutdown (LS1) was mainly dedicated to the consolidation of the LHC magnet interconnections, to allow the LHC to operate at its design beam energy of 7 TeV. Other key accelerator systems have also been improved to optimize the performance reach at higher beam energies. After a review of the LS1 activities, the status of the LHC start-up progress is reported, addressing in particular the status of the LHC hardware commissioning and of the training campaign of superconducting magnets that will determine the operation beam energy in 2015. Then, the plans for the Run II operation are reviewed in detail, covering choice of initial machine parameters and strategy to improve the Run II performance. Future prospects of the LHC and its upgrade plans are also presented.

Snapshots to shed light on LHC performance

CERN Multimedia

2006-01-01

With the impressive size and unprecedented power of the LHC, it is all too easy to overlook the smaller devices that have the difficult task of monitoring the new accelerator. You don't have to stand too far back from the big picture to see examples of clever technology inside the LHC. One of the undulators installed in the LHC tunnel can be seen on the right of the photo. From right to left, back row: Lucio Rossi (group leader, MCS), Davide Tommasini (conceptual design, MCS), Thierry Tenaglia (integration design,TS-MME), Remo Maccaferri (project leader, MCS) and Hans Kummer (MCS/ME); front row: Gilles Trachez (MCS-ME) and Bruno Meunier (FSU-AT12). In contrast to the usual articles about the LHC's big number statistics, examples of clever problem-solving found in beam monitoring machinery show that smaller things can be beautiful too. The design of the LHC accelerator brought new challenges for monitoring the shape of the particle beam, known as the beam profile. The size of the beam shrinks as higher energi...

LHC Magnet test failure

CERN Multimedia

2007-01-01

"On Tueday, March 22, a Fermilab-built quadrupole magnet, one of an "inner triplet" of three focusing magnets, failed a high-pressure test at Point 5 in the tunnel of the LHC accelerator at CERN. Since Tuesday, teams at CERN and Fermilab have worked closely together to address the problem and have identified the cause of the failure. Now they are at work on a solution.:" (1 page)

ST/EL and ST/CV services for TI2 & TI8 LHC injection tunnels

CERN Document Server

Akhtar, S; CERN. Geneva. ST Division

2002-01-01

This paper describes the ST/EL and ST/CV services for TI2 & TI8 LHC injection tunnels. The cooling and ventilation part describes the requirements for design and installation of more than 10 km of pipeline that is going to be laid down in the tunnels. Main operating parameters as well as manufacture procedures are explained. Preliminary work schedule with the cost estimate is also presented. Electrical power will be distributed from the LHC side and the SPS side for the machine and the general services. All power converters will be installed on surface buildings. The link between the main bend converters and the main bend magnets will be realised with water-cooled cables. Rest of the magnets will be cabled by using conventional copper and aluminium cables. Due to long lengths of the injection tunnels a dry 18kV transformer will be installed in TJ8 to serve the general services for TI8. The same will apply to TI2 by installing a transformer at the bottom of the PMI2 shaft.

14 November 2013 - Director of Indian Institute of Technology Indore P. Mathur with members of the Indian community working at CERN; visiting the LHC tunnel at Point 2, the ALICE experimental area and SM18 with ALICE Collaboration Spokesperson, Istituto Nazionale Fisica Nucleare P. Giubellino and Technology Department, Accelerator Beam Transfer Group Leader V. Mertens

CERN Multimedia

Jean-Claude Gadmer

2013-01-01

14 November 2013 - Director of Indian Institute of Technology Indore P. Mathur with members of the Indian community working at CERN; visiting the LHC tunnel at Point 2, the ALICE experimental area and SM18 with ALICE Collaboration Spokesperson, Istituto Nazionale Fisica Nucleare P. Giubellino and Technology Department, Accelerator Beam Transfer Group Leader V. Mertens

HL-LHC Accelerator

CERN Document Server

Zimmermann, F

2013-01-01

The tentative schedule, key ingredients, as well as progress of pertinent R&D and component prototypes for the LHC luminosity upgrade, "HL-LHC," are reviewed. Also alternative scenarios based on performance-improving consolidations (PICs) instead of a full upgrade are discussed. Tentative time schedules and expected luminosity evolutions for the different scenarios are sketched. The important role of HL-LHC development as a step towards a future HE-LHC or VHE-LHC is finally highlighted. Presented at "Higgs & Beyond" Conference Tohoku University, Sendai 7 June 2013.

LHC Report: Rehearsing the LHC accelerator systems for the Run 2 start-up with beam

CERN Multimedia

Reyes Alemany Fernandez

2015-01-01

While the commissioning of the superconducting circuits is ongoing, great care is also being taken to make sure that the other key LHC accelerator systems are qualified for beam. Since spring 2014, small-scale integration tests on the accelerator systems have been scheduled and carried out successfully to exercise them fully and thoroughly debug their multiple interfaces. The LHC Operations team leads this activity in tight collaboration with the equipment experts and the essential support of the Accelerator Controls group. The tests start once individual system qualification has been performed by the equipment owners and they are ready to be handed over to operations. These tests performed by Operations are called dry runs – dry because they are performed without beam – and they are carried out from the CERN Control Centre (CCC) using the same high-level software applications that will be used during beam operation. The dry runs are the first step towards a global integration test ...

The Real-Time Data Analysis and Decision System for Particle Flux Detection in the LHC Accelerator at CERN.

CERN Document Server

Zamantzas, C; Dehning, B

2006-01-01

The superconducting Large Hadron Collider (LHC) under construction at the European Organisation for Nuclear Research (CERN) is an accelerator unprecedented in terms of beam energy, particle production rate and also in the potential of self-destruction. Its operation requires a large variety of instrumentation, not only for the control of the beams, but also for the protection of the complex hardware systems. The Beam Loss Monitoring (BLM) system has to prevent the superconducting magnets from becoming normal conducting and protect the machine components against damages making it one of the most critical elements for the protection of the LHC. For its operation, the system requires 3600 detectors to be placed at various locations around the 27 km ring. The measurement system is sub-divided to the tunnel electronics, which are responsible for acquiring, digitising and transmitting the data, and the surface electronics, which receive the data via 2 km optical data links, process, analyze, store and issue warning...

The LHC personnel safety system

International Nuclear Information System (INIS)

Ninin, P.; Valentini, F.; Ladzinski, T.

2011-01-01

Large particle physics installations such as the CERN Large Hadron Collider require specific Personnel Safety Systems (PSS) to protect the personnel against the radiological and industrial hazards. In order to fulfill the French regulation in matter of nuclear installations, the principles of IEC 61508 and IEC 61513 standard are used as a methodology framework to evaluate the criticality of the installation, to design and to implement the PSS.The LHC PSS deals with the implementation of all physical barriers, access controls and interlock devices around the 27 km of underground tunnel, service zones and experimental caverns of the LHC. The system shall guarantee the absence of personnel in the LHC controlled areas during the machine operations and, on the other hand, ensure the automatic accelerator shutdown in case of any safety condition violation, such as an intrusion during beam circulation. The LHC PSS has been conceived as two separate and independent systems: the LHC Access Control System (LACS) and the LHC Access Safety System (LASS). The LACS, using off the shelf technologies, realizes all physical barriers and regulates all accesses to the underground areas by identifying users and checking their authorizations.The LASS has been designed according to the principles of the IEC 61508 and 61513 standards, starting from a risk analysis conducted on the LHC facility equipped with a standard access control system. It consists in a set of safety functions realized by a dedicated fail-safe and redundant hardware guaranteed to be of SIL3 class. The integration of various technologies combining electronics, sensors, video and operational procedures adopted to establish an efficient personnel safety system for the CERN LHC accelerator is presented in this paper. (authors)

A word from the DG - Major progress for the LHC

CERN Multimedia

2006-01-01

The return to work after the summer holiday period has been marked by significant progress in the installation of the LHC machine and its detectors. At the beginning of the month, the one thousandth superconducting magnet was positioned in the accelerator tunnel. Passing this symbolic milestone is a testament to the successful efforts of the hundreds of LHC collaborators who are working day and night to install the machine in time, and I would like to take this opportunity to congratulate them. Despite the significant technical and organisational difficulties associated with different types of activities being carried out in parallel in a tunnel where space is limited, the LHC installation teams have achieved remarkable feats. As a result, the delays incurred owing to the problems encountered with the cryogenic distribution line in 2004 have been partly recouped. The cryoline is almost complete, with seven out of eight sectors accepted while installation of the eighth is expected to be completed at the...

The LHC Superconducting RF System

CERN Document Server

Boussard, Daniel

1999-01-01

The European Laboratory for Particle Physics (CERN), the largest high energy physics laboratory worldwide, is constructing the Large Hadron Collider (LHC) in the existing 27 km circumference LEP (Large Electron Positron) collider tunnel. For the LHC, superconducting cavities, operating at 4.5 K, will provide the required acceleration field for ramping the beam energy up to 7 TeV and for keeping the colliding proton beams tightly bunched. Superconducting cavities were chosen, not only because of their high acceleration field leading to a small contribution to the machine impedance, but also because of their high stored energy which minimises the effects of periodic transient beam loading associated with the high beam intensity (0.5 A). There will be eight single-cell cavities per beam, each delivering 2 MV (5.3 MV/m) at 400 MHz. The cavities themselves are now being manufactured by industrial firms, using niobium on copper technology which gives full satisfaction at LEP. A complete cavity prototype assembly in...

QPS/LHC Activities requiring important Tunnel Work During a future long Shutdown

CERN Document Server

Dahlerup-Petersen, K

2011-01-01

The MPE/circuit protection section is presently establishing a road map for its future LHC activities. The tasks comprise essential consolidation work, compulsory upgrades and extensions of existing machine facilities. The results of a first round of engineering exertion were presented and evaluated at a MPE activity review in December 2010. The technical and financial aspects of this program will be detailed in the ‘QPS Medium and Long-Term Improvement Plan’, to be published shortly. The QPS activities in the LHC tunnel during a future, long shutdown are closely related to this improvement chart. A project-package based program for the interventions has been established and will be presented in this report, together with estimates for the associated human and financial resources necessary for its implementation.

Coldbox installation for HL-LHC crab cavity test in the SPS tunnel (BA6)

CERN Document Server

Ordan, Julien Marius

2018-01-01

The Cold-box, produced by Linde Kryotechnik for the SPS crab-cavity test stand for HL-LHC, on its arrival at CERN. It wll be transported into the tunnel in horizontal position and then will have to be tilted in its operational position, on its vertical axis, before connecting it to cryogenics lines.

LHC Report: The machine under maintenance

CERN Multimedia

Katy Foraz for the LHC Team

2012-01-01

The LHC Christmas break started on 12 December. Since then, teams have been working hard to complete all the maintenance work planned to ensure the reliable operation of the LHC in 2012.   Installation of shielding at Point 1. The maintenance work is being carried out on key infrastructure such as the cooling, ventilation, electricity and safety systems. Maintenance work is being carried out not just in the LHC but also across the whole accelerator complex, which makes planning the work even more complicated. At the time of going to print, 50% of the cryogenics system maintenance has been finished, which, according to the schedule, will allow the LHC teams to start cooling down the first sectors next week to have the entire machine cold by the end of February. A lot of activity is going on in order to mitigate the effects of radiation on equipment installed in the LHC tunnel and underground areas during 2012 operation. To this end, teams have installed additional shielding at Point 1 (see ph...

Installation of wireless LAN system into the SuperKEKB accelerator tunnel

International Nuclear Information System (INIS)

Iwasaki, Masako; Satoh, Masanori

2014-01-01

We have installed a wireless LAN system of the accelerator control network into the accelerator tunnel for SuperKEKB, which is the upgrade plan of the KEKB B-factory project. The wireless LAN system is used for the construction and maintenance of the accelerator components. The leaky coaxial cable (LCX) antennas are installed into the arc sections of SuperKEKB tunnel, and the collinear antennas are installed into the straight sections and the injector Linac. We have selected the LCX and collinear antennas with good radiation hardness of more than 1 MGy. After the installation, we evaluated the wireless LAN system and obtained the good network speed performance in the whole tunnel area. (author)

LS1 Report: across the accelerator complex

CERN Multimedia

Simon Baird

2013-01-01

The warm-up of the first LHC sector (5-6) is now complete; it is at room temperature for the first time in over three years. Next week, the W bellows in this sector will be opened in preparation for the consolidation of the superconducting circuits, splices and interconnections (the SMACC project). Elsewhere in the LHC, the ELQA tests and the warm-up of the remaining seven sectors are proceeding as planned.   Vacuum leak tests are performed on the magnets before the LHC is brought up to ambient temperature. The SPS magnet test programme was completed on 26 March and work has already begun in the SPS tunnel. Among the activities being carried out is the installation of 16 specially coated vacuum chambers in the SPS main dipole magnets around BA5. The first of these dipole magnets were removed from the SPS tunnel today, Friday 5 April. By reducing the build-up of electron clouds around the LHC beam during acceleration in the SPS, this activity will play a key role in the increase of LHC beam in...

Flat bunch creation and acceleration: a possible path for the LHC luminosity upgrade

International Nuclear Information System (INIS)

Bhat, C.M.

2009-01-01

Increasing the collider luminosity by replacing bunches having Gaussian line-charge distribution with flat bunches, but with same beam-beam tune shift at collision, has been studied widely in recent years. But, creation of 'stable' flat bunches (and their acceleration) using a multiple harmonic RF system has not been fully explored. Here, we review our experience with long flat bunches in the barrier RF buckets at Fermilab.We presentsome preliminary results from beam dynamics simulations and recent beam studies in the LHC injectors to create stable flat bunches using double harmonic RF systems. The results deduced from these studies will be used to model the necessary scheme for luminosity upgrade in the LHC. We have also described a viable (and economical) way for creation and acceleration of flat bunches in the LHC. The flat bunch scheme may have many advantages over the LHC baseline scenario, particularly because of the reduced momentum spread of the bunch for increased intensities.

Displacement measurements in the cryogenically cooled dipoles of the new CERN-LHC particle accelerator

CERN Document Server

Inaudi, D; Scandale, Walter; Pérez, J G; Billan, J; Redaelli, S

2001-01-01

The LHC will use the most advanced superconducting magnet and accelerator technologies ever employed. One of the main challenges in this new machine resides in the design and production of the superconducting dipoles used to steer the particles around the 27 km underground tunnel. These so-called cryodipoles are composed of an external vacuum tube and an insert, appropriately named the cold mass, that contains the particle tubes, the superconducting coil and will be cooled using superfluid helium to 1.9 K. The particle beam must be placed inside the magnetic field with a submillimeter accuracy; this requires in turn that the relative displacements between the vacuum tube and the cold-mass must be monitored with accuracy. Due to the extreme condition environmental conditions (the displacement measurement must be made in vacuum and between two points with a temperature difference of more than 200 degrees C) no adequate existing monitoring system was found for this application. It was therefore decided to develo...

The Development of the Control System for the Cryogenics in the LHC Tunnel

CERN Document Server

Fluder, C; Casas-Cubillos, J; Dubert, P; Gomes, P; Pezzetti, M; Tovar-Gonzalez, A; Zwalinski, L

2011-01-01

The Large Hadron Collider (LHC) was commissioned at CERN and started operation with beams in 2008. The LHC makes extensive use of superconductors, in magnets, electrical feed boxes and accelerating cavities, which are operated at cryogenic temperatures. The process automation for the cryogenic distribution around the 27 km accelerator circumference is based on 18 Programmable Logic Controllers (PLCs); overall, they handle 4 000 control loops and 8 000 alarms and interlocks; 16 000 cryogenic sensors and actuators are accessed through industrial field networks. This paper reviews the control system architecture and the main hardware and software components; presents the hardware commissioning and software production methodologies; and illustrates some of the problems faced during development, commissioning and nominal cryogenics operation, together with the solutions applied.

LHC Report: Even accelerators need a break

CERN Multimedia

CERN Bulletin

2011-01-01

The LHC technical stop is in full swing, with a lot of essential maintenance work on the accelerator services, such as electricity distribution, cooling, ventilation, cryogenic systems, access and safety systems, vacuum, cranes and lifts, being crammed into the few weeks before the start of the 2011 run in February.   Team changing a magnet in the SPS accelerator.  In addition to the maintenance work a number of modifications are being made to the accelerator for 2011. These include the installation of small solenoids to combat the build-up of electrons inside the vacuum chamber with the increasing proton beam intensity; the replacement of a number of UPS (Uninterruptible Power Supply) installations, which are vital to ensuring the continuity of the electrical supply to essential systems such as the cryogenics; the installation of additional capacitors on the QPS (Quench Protection system) to prepare for a possible increase in beam energy in 2011; the completion of the programme to repla...

The LHC goes 3G

CERN Multimedia

Anaïs Schaeffer

2013-01-01

A new telecommunications network has been installed in the LHC tunnel to facilitate operations during the long shutdown. Anyone using a smartphone, tablet or laptop computer will now be able to access the Internet from the tunnel.   Results of a download (green) and upload (yellow) test carried out in the LHC tunnel using the new Universal Mobile Telecommunications System (UMTS). The first long shutdown has officially begun, and the teams are about to enter the various tunnels around the Laboratory. It’s a good opportunity to talk telecommunications. As you can well imagine, even the highest of high-tech smartphones remains stubbornly silent and unresponsive 100 metres below the ground. Except at CERN… The IT-CS Group has implemented an impressive state-of-the-art solution to tackle this problem - a new Universal Mobile Telecommunications System (UMTS), better known as “3G”, covering the entire 27-km circumference of the LHC tunnel. Established on th...

Winter therapy for the accelerators

CERN Multimedia

Corinne Pralavorio

2016-01-01

Hundreds of people are hard at work during the year-end technical stop as all the accelerators are undergoing maintenance, renovation and upgrade operations in parallel.   The new beam absorber on its way to Point 2 before being lowered into the LHC tunnel for installation. The accelerator teams didn’t waste any time before starting their annual winter rejuvenation programme over the winter. At the end of November, as the LHC ion run was beginning, work got under way on the PS Booster, where operation had already stopped. On 14 December, once the whole complex had been shut down, the technical teams turned their attention to the other injectors and the LHC. The year-end technical stop (YETS) provides an opportunity to carry out maintenance work on equipment and repair any damage as well as to upgrade the machines for the upcoming runs. Numerous work projects are carried out simultaneously, so good coordination is crucial. Marzia Bernardini's team in the Enginee...

Nonlinear predictive control in the LHC accelerator

CERN Document Server

Blanco, E; Cristea, S; Casas, J

2009-01-01

This paper describes the application of a nonlinear model-based control strategy in a real challenging process. A predictive controller based on a nonlinear model derived from physical relationships, mainly heat and mass balances, has been developed and commissioned in the inner triplet heat exchanger unit (IT-HXTU) of the large hadron collider (LHC) particle accelerator at European Center for Nuclear Research (CERN). The advanced regulation\\ maintains the magnets temperature at about 1.9 K. The development includes a constrained nonlinear state estimator with a receding horizon estimation procedure to improve the regulator predictions.

LHC Injection Beam Quality During LHC Run I

CERN Document Server

AUTHOR|(CDS)2079186; Kain, Verena; Stapnes, Steinar

The LHC at CERN was designed to accelerate proton beams from 450 GeV to 7 TeV and collide them in four large experiments. The 450 GeV beam is extracted from the last pre-accelerator, the SPS, and injected into the LHC via two 3 km long transfer lines, TI 2 and TI 8. The injection process is critical in terms of preservation of beam quality and machine protection. During LHC Run I (2009-2013) the LHC was filled with twelve high intensity injections per ring, in batches of up to 144 bunches of 1.7*10^11 protons per bunch. The stored beam energy of such a batch is already an order of magnitude above the damage level of accelerator equipment. Strict quality and machine protection requirements at injection have a significant impact on operational efficiency. During the first years of LHC operation, the injection phase was identified as one of the limiting factors for fast LHC turnaround time. The LHC Injection Quality Check (IQC) software framework was developed as a part of this thesis to monitor the beam quality...

9 April 2013 - Minister for Universities and Science United Kingdom of Great Britain and Northern Ireland D. Willetts in the ATLAS experimental cavern with ATLAS Collaboration Spokesperson D. Charlton and in the LHC tunnel at Point 1 with Beams Department Head P. Collier. Director for Accelerators and Technology S. Myers, Editor at the Communication Group K. Kahle and Beams Department Engineer R. Veness present.

CERN Multimedia

Jean-Claude Gadmer

2013-01-01

9 April 2013 - Minister for Universities and Science United Kingdom of Great Britain and Northern Ireland D. Willetts in the ATLAS experimental cavern with ATLAS Collaboration Spokesperson D. Charlton and in the LHC tunnel at Point 1 with Beams Department Head P. Collier. Director for Accelerators and Technology S. Myers, Editor at the Communication Group K. Kahle and Beams Department Engineer R. Veness present.

Acoustic measurements in the collimation region of the LHC

CERN Document Server

Deboy, D; Baccigalupi, C; Burkart, F; Cauchi, M; Derrez, C S; Lendaro, J; Masi, A; Spiezia, G; Wollmann, D

2011-01-01

The LHC accelerator at CERN has the most advanced collimation system ever being installed. The collimators intercept unavoidable particle losses and therefore are essential to avoid beam induced quenches of the superconducting magnets. In addition, they provide passive machine protection against mis-kicked beams. During material robustness tests on a LHC collimator prototype in 2004 and 2006, vibration and acoustic measurements have shown that a beam impact detection system should be feasible using accelerometers and microphones as sensors in the LHC. Recently, such sensors have been installed close to the primary collimators in the LHC tunnel. First analyses of raw data show that the system is sensitive enough to detect beam scraping on collimators. Therefore, the implementation of a sophisticated acousticmonitoring system is under investigation. It may be useful not only to detect beam impacts on primary collimators in case of failure, but also to derive further information on beam losses that occur during ...

LHC train control system for autonomous inspections and measurements

OpenAIRE

Di Castro, Mario; Baiguera Tambutti, Maria Laura; Gilardoni, Simone; Losito, Roberto; Lunghi, Giacomo; Masi, Alessandro

2018-01-01

Intelligent robotic systems are becoming essential for inspection and measurements in harsh environments, such as the European Organization for Nuclear Research (CERN) accelerators complex. Aiming at increasing safety and machine availability, robots can help to perform repetitive or dangerous tasks, reducing the risk for the personnel as the exposure to radiation. The Large Hadron Collider (LHC) tunnel at CERN has been equipped with fail-safe trains on monorail able to perform autonomously d...

Using permanent magnets to boost the dipole field for the High-Energy LHC

CERN Document Server

Zimmermann, Frank

2012-01-01

The High-Energy LHC (HE-LHC) will be a new accelerator in the LHC tunnel based on novel dipole magnets, with a field up to 20 T, which are proposed to be realized by a hybrid-coil design, comprising blocks made from Nb- Ti, Nb$_{3}$Sn and HTS, respectively. Without the HTS the field would be only 15 T. In this note we propose and study the possibility of replacing the inner HTS layer by (weaker) permanent magnets that might contribute a field of 1-2 T, so that the final field would reach 16-17 T. Advantages would be the lower price of permanent magnets compared with HTS magnets and their availability in principle.

Quantum Diaries Blog: Is the moon full? Just ask the LHC operators

CERN Multimedia

Pauline Gagnon

2012-01-01

Corrections to proton orbits in the LHC appear as regular dips in the instantaneous luminosity measured by CMS (beige) and ATLAS (green).   The LHC is so large that the gravitational force exerted by the moon is not the same at all points, which creates small distortions of the tunnel. And the machine is sensitive enough to detect minute deformations created by the small differences in gravitational force across its diameter. Therefore, the orbits of protons in the accelerator have to be adjusted regularly to account for the gravitational effect of the moon. Read more on the Quantum Diaries Blog post.

Super High Energy Colliding Beam Accelerators

International Nuclear Information System (INIS)

Abdelaziz, M.E.

2009-01-01

This lecture presents a review of cyclic accelerators and their energy limitations. A description is given of the phase stability principle and evolution of the synchrotron, an accelerator without energy limitation. Then the concept of colliding beams emerged to yield doubling of the beam energy as in the Tevatron 2 trillion electron volts (TeV) proton collider at Fermilab and the Large Hadron Collider (LHC) which is now planned as a 14-TeV machine in the 27 kilometer tunnel of the Large Electron Positron (LEP) collider at CERN. Then presentation is given of the Superconducting Supercollider (SSC), a giant accelerator complex with energy 40-TeV in a tunnel 87 kilometers in circumference under the country surrounding Waxahachie in Texas, U.S.A. These superhigh energy accelerators are intended to smash protons against protons at energy sufficient to reveal the nature of matter and to consolidate the prevailing general theory of elementary particle.

18 January 2011 - Ing. Vittorio Malacalza, ASG Superconductors S.p.A, Italy in the LHC superconducting magnet test hall with Deputy Department Head L. Rossi, in the LHC tunnel at Point 5 and CMS experimental area with Spokesperson G. Tonelli.

CERN Multimedia

Maximilien Brice

2011-01-01

18 January 2011 - Ing. Vittorio Malacalza, ASG Superconductors S.p.A, Italy in the LHC superconducting magnet test hall with Deputy Department Head L. Rossi, in the LHC tunnel at Point 5 and CMS experimental area with Spokesperson G. Tonelli.

27 January 2012 - Mitglieder des Stiftungsrates Academia Engelberg und Gesellschaft zum Bettag Luzern Schweiz welcomed by Head of International Relations F. Pauss; visiting LHC tunnel at Point 5 and CMS experimental cavern; in the LHC superconducting magnet test hall SM18.

CERN Multimedia

Maximilien Brice

2012-01-01

27 January 2012 - Mitglieder des Stiftungsrates Academia Engelberg und Gesellschaft zum Bettag Luzern Schweiz welcomed by Head of International Relations F. Pauss; visiting LHC tunnel at Point 5 and CMS experimental cavern; in the LHC superconducting magnet test hall SM18.

Important step towards the LHC

CERN Document Server

2001-01-01

The TI2 tunnel, one of the two tunnels that will transfer protons from the SPS to the LHC, broke through into the LEP/LHC ring on 15 May. TI2 will carry clockwise-moving protons from under the Laboratory's West Area to Point 2, future home of the ALICE experiment. It is coming up to 16:00 on 15 May and a group of some 50 people, fully kitted out in boots, helmets, and masks is intently watching a point on the wall in front of them. They are down in the LEP/LHC tunnel waiting for civil engineers to excavate the last few centimetres separating them from the TI2 transfer tunnel. The noise of machines begins, and just five minutes later the wall comes tumbling down. The excavator breaks through right on target, bringing a two-year project to a happy conclusion. Later, the survey team published the outstanding result that the tunnel junction was made within 6 millimetres of target. TI2 measures 2648 metres in length and three metres in diameter. Around 32,000 cubic metres of rock have been excavated to make it, so...

Exergy Analysis of the Cryogenic Helium Distribution System for the Large Hadron Collider (LHC)

CERN Document Server

Claudet, S; Tavian, L; Wagner, U

2010-01-01

The Large Hadron Collider (LHC) at CERN features the world’s largest helium cryogenic system, spreading over the 26.7 km circumference of the superconducting accelerator. With a total equivalent capacity of 145 kW at 4.5 K including 18 kW at 1.8 K, the LHC refrigerators produce an unprecedented exergetic load, which must be distributed efficiently to the magnets in the tunnel over the 3.3 km length of each of the eight independent sectors of the machine. We recall the main features of the LHC cryogenic helium distribution system at different temperature levels and present its exergy analysis, thus enabling to qualify second-principle efficiency and identify main remaining sources of irreversibility..

EXERGY ANALYSIS OF THE CRYOGENIC HELIUM DISTRIBUTION SYSTEM FOR THE LARGE HADRON COLLIDER (LHC)

International Nuclear Information System (INIS)

Claudet, S.; Lebrun, Ph.; Tavian, L.; Wagner, U.

2010-01-01

The Large Hadron Collider (LHC) at CERN features the world's largest helium cryogenic system, spreading over the 26.7 km circumference of the superconducting accelerator. With a total equivalent capacity of 145 kW at 4.5 K including 18 kW at 1.8 K, the LHC refrigerators produce an unprecedented exergetic load, which must be distributed efficiently to the magnets in the tunnel over the 3.3 km length of each of the eight independent sectors of the machine. We recall the main features of the LHC cryogenic helium distribution system at different temperature levels and present its exergy analysis, thus enabling to qualify second-principle efficiency and identify main remaining sources of irreversibility.

Maintenance des équipements de transport pour l'installation des cryo-aimants dans le tunnel LHC

CERN Document Server

Chevalley, JM

2005-01-01

Le transport et l’installation de quelque 1800 cryo-aimants dans le tunnel LHC seront réalisés à l’aide d’équipements de transport et de manutention de haute technologie spécialement développés par le groupe TS-IC. La section HM devra assurer la maintenance de toute cette chaîne d’équipements : le pont roulant pour la descente des cryo-aimants dans le tunnel LHC, les véhicules de transport spéciaux alimentés dans le tunnel par la gaine monorail et enfin les tables de transfert utilisées pour la mise en place finale des cryo-aimants sur leurs vérins. Dans ce cadre, plusieurs aspects seront développés dans ce document : la mise en place et l’organisation de la maintenance, l’analyse des modes de défaillance et de leur criticité (AMDEC), les différentes méthodes possibles pour la recherche et résolution des pannes, ainsi que le suivi du projet, et ce dans le but de fiabiliser et d†™assurer le bon fonctionnement de t...

Towards LHC experiments

International Nuclear Information System (INIS)

Anon.

1992-01-01

As plans for the LHC proton collider to be built in CERN's 27-kilometre LEP tunnel take shape, interest widens to bring in the experiments exploiting the big machine. The first public presentations of 'expressions of interest' for LHC experiments featured from 5-8 March at Evian-les-Bains on the shore of Lake Geneva, some 50 kilometres from CERN, at the special Towards the LHC Experimental Programme' meeting

Preliminary accelerator plans for maximizing the integrated LHC luminosity

CERN Document Server

Benedikt, Michael; Ruggiero, F; Ostojic, R; Scandale, Walter; Shaposhnikova, Elena; Wenninger, J

2006-01-01

A working group on "Proton Accelerators for the Future" (PAF) has been created in May 2005 by the CERN direction to elaborate a baseline scenario of the possible development and upgrade of the present Proton Accelerator Complex. This report is the result of the investigation conducted until the end of 2005, in close connection with the working group on "Physics Opportunities with Future Proton Accelerators" (POFPA) and is consistent with their recommendations. Focused on the goal of maximizing the integrated luminosity for the LHC experiments, a scenario of evolution is proposed, subject to further refinement using the future experience of commissioning and running-in the collider and its injector complex. The actions to be taken in terms of consolidation, R & D and improvement are outlined. The benefits for other types of physics are mentioned and will be investigated in more detail in the future.

The commissioning of the instrumentation for the LHC tunnel cryogenics

CERN Document Server

Avramidou, R; Bamis, C; Casas-Cubillos, J; Dragoneas, A; Fampris, X; Fernandez-Penacoba, G; Gomes, P; Gousiou, E; Jeanmonod, N; Karagiannis, F; Koumparos, A; Leontsinis, S; Lopez-Lorente, A; Patsouli, A; Polychroniadis, I; Suraci, A; Theodoropoulos, G; Vauthier, N; Vottis, C

2007-01-01

The Large Hadron Collider (LHC) at CERN is a superconducting accelerator and proton-proton collider of circumference of 27 km, lying about 100 m underground. Its operation relies on 1232 superconducting dipoles with a field of 8.3 T and 392 superconducting quadrupoles with a field gradient of 223 T/m powered at 11.8 kA and operating in superfluid helium at 1.9 K. This paper describes the cryogenic instrumentation commissioning, the challenges and the project organization based on our 2.5 years experience.

Proposal to negotiate amendments to an existing contract for the supply of steel structures for the LHC shafts, tunnels, caverns and experimental areas

CERN Document Server

2005-01-01

This document concerns the proposal to negotiate amendments to an existing contract for the supply of additional steel structures for the LHC shafts, tunnels, caverns and experimental areas. For the reasons explained in this document, the Finance Committee is invited to approve amendments to the existing contract with the firm INIZIATIVE INDUSTRIALI (IT) for the supply of additional steel structures for the LHC shafts, tunnels, caverns and experimental areas for an amount of 500 000 euros (775 000 Swiss francs), subject to revision for inflation, bringing the total to 6 525 745 euros (10 114 905 Swiss francs), subject to revision for inflation. The amounts in Swiss francs have been calculated using the present rate of exchange.

First Experience with the LHC Cryogenic Instrumentation

CERN Document Server

Vauthier, N; Balle, Ch; Casas-Cubillos, J; Ciechanowski, M; Fernandez-Penacoba, G; Fortescue-Beck, E; Gomes, P; Jeanmonod, N; Lopez-Lorente, A; Suraci, A

2008-01-01

The LHC under commissioning at CERN will be the world's largest superconducting accelerator and therefore makes extensive use of cryogenic instruments. These instruments are installed in the tunnel and therefore have to withstand the LHC environment that imposes radiation-tolerant design and construction. Most of the instruments require individual calibration; some of them exhibit several variants as concerns measuring span; all relevant data are therefore stored in an Oracle® database. Those data are used for the various quality assurance procedures defined for installation and commissioning, as well as for generating tables used by the control system to configure automatically the input/output channels. This paper describes the commissioning of the sensors and the corresponding electronics, the first measurement results during the cool-down of one machine sector; it discusses the different encountered problems and their corresponding solutions.

LHC - latest in a long line of rings

Energy Technology Data Exchange (ETDEWEB)

Anon.

1993-12-15

The LHC - Large Hadron Collider - ring in CERN's 27-kilometre LEP tunnel is the natural next link in an accelerator chain first forged in the mid-1950s with the decision to build Europe's first state-of-the-art high energy synchrotron at CERN. A lot of ground has been covered since the LHC idea was launched over a decade ago. While the basic machine design has moved through several iterations, preparations for the experimental programme are well underway. CERN is now responding to the December 1991 request from its governing body, Council, to supply detailed information on the technical feasibility of the machine, its costs, and its experimental programme. In the late 1970s, when plans for CERN's LEP electron-positron collider were being pieced together, far-sighted people were already looking further ahead. With the LEP tunnel itself a major investment for the future, the circumference of the ring and the tunnel cross-section were kept as large as possible, so that another ring could be fitted in when the time came. On the physics front, the ultimate quest was the mysterious higgs mechanism which controls electroweak symmetry breaking. The symmetry of the vacuum is broken by the higgs field. Somewhere along the line, this fundamental field has to show itself as one or more higgs particles.

LHC - latest in a long line of rings

International Nuclear Information System (INIS)

Anon.

1993-01-01

The LHC - Large Hadron Collider - ring in CERN's 27-kilometre LEP tunnel is the natural next link in an accelerator chain first forged in the mid-1950s with the decision to build Europe's first state-of-the-art high energy synchrotron at CERN. A lot of ground has been covered since the LHC idea was launched over a decade ago. While the basic machine design has moved through several iterations, preparations for the experimental programme are well underway. CERN is now responding to the December 1991 request from its governing body, Council, to supply detailed information on the technical feasibility of the machine, its costs, and its experimental programme. In the late 1970s, when plans for CERN's LEP electron-positron collider were being pieced together, far-sighted people were already looking further ahead. With the LEP tunnel itself a major investment for the future, the circumference of the ring and the tunnel cross-section were kept as large as possible, so that another ring could be fitted in when the time came. On the physics front, the ultimate quest was the mysterious higgs mechanism which controls electroweak symmetry breaking. The symmetry of the vacuum is broken by the higgs field. Somewhere along the line, this fundamental field has to show itself as one or more higgs particles

Discovery Mondays - 'The LHC: an accelerator of science'

CERN Multimedia

2006-01-01

Is the LHC about to turn the theories of the infinitesimally small on their heads? Whether or not this proves to be the case, physicists hope that the 27-kilometre-long accelerator due to be commissioned at the end of 2007 will shake up the Standard Model. This theory, which describes elementary particles and forces, leaves many questions unanswered. The LHC and its experiments have been designed to shed light on them. Unresolved questions include how elementary particles acquire mass and why their masses differ. The disappearance of antimatter from our Universe is another such mystery. Physicists want to know what matter was like just after the Big Bang and what the dark matter in the Universe could be: only 5% of the matter of the Universe is visible, and the effects of gravity indicate the presence of another type of matter that cannot be seen by the instruments available today. The theory of supersymmetry, which predicts that each particle has a corresponding superparticle, could go some way towards exp...

Electron cloud in the CERN accelerators (PS, SPS, LHC)

International Nuclear Information System (INIS)

Iadarola, G; Rumolo, G

2013-01-01

Several indicators have pointed to the presence of an Electron Cloud (EC) in some of the CERN accelerators, when operating with closely spaced bunched beams. In particular, spurious signals on the pick ups used for beam detection, pressure rise and beam instabilities were observed at the Proton Synchrotron (PS) during the last stage of preparation of the beams for the Large Hadron Collider (LHC), as well as at the Super Proton Synchrotron (SPS). Since the LHC has started operation in 2009, typical electron cloud phenomena have appeared also in this machine, when running with trains of closely packed bunches (i.e. with spacings below 150ns). Beside the above mentioned indicators, other typical signatures were seen in this machine (due to its operation mode and/or more refined detection possibilities), like heat load in the cold dipoles, bunch dependent emittance growth and degraded lifetime in store and bunch-by-bunch stable phase shift to compensate for the energy loss due to the electron cloud. An overview of the electron cloud status in the different CERN machines (PS, SPS, LHC) will be presented in this paper, with a special emphasis on the dangers for future operation with more intense beams and the necessary countermeasures to mitigate or suppress the effect. (author)

2008 LHC Open Days LHC magnets on display

CERN Multimedia

2008-01-01

Over the last few years you’ve probably seen many of the 15 m long blue LHC dipole magnets being ferried around the site. Most of them are underground now, but on the LHC Open Days on 5 and 6 April the magnets will also play a central role on the surface. Installation of one of the LHC dipole magnets on the Saint-Genis roundabout on 7 March. The LHC dipole testing facility with several magnets at various stages of testing. The 27 km ring of the LHC consists of 1232 double-aperture superconducting dipole magnets, 360 short straight sections (SSS) and 114 special SSS for the insertion regions. On the Open Day, you will be able to "Follow the LHC magnets" through different stages around the site, culminating in their descent into the tunnel. Discover all the many components that have to be precisely integrated in the magnet casings, and talk to the engine...

CERN Open Days 2013, Point 4: LHC Radio Frequency

CERN Multimedia

CERN Photolab

2013-01-01

Stand description: At Point 4 visitors will descend into the LHC tunnel to see the "engine" of the collider: the accelerating cavities where the circulating particles get a small kick of energy as they pass by 11,000 times each second. During your visit underground, you will see the superconducting magnets as well as instruments for observing the beams. You will also walk through the huge cavern containing the Radio Frequency power plants which provide the particle beams with energy. On surface no restricted access  Above ground, you will see the cryogenics installations which keep the accelerator at a just few degrees above absolute zero. Lots of fascinating information and exhibits about CERN's accelerators and experiments will be on display, with CERN engineers and physicists on hand all day to answer your questions.

A Virtual CAD Model of the LHC

CERN Document Server

Chemli, S; Messerli, R; Muttoni, Y; Prin, H; Van Uytvinck, E

2000-01-01

Integrating the large and complex LHC machine into the existing LEP tunnel is a major challenge. Space was not really a problem to fit the LEP machine into its tunnel, but LHC cryostats are much larger than the LEP quadrupoles and the external cryogenic line fills even more the tunnel. Space problems lead to small clearances. Possible conflicts, or at least the most penalising ones, between installed equipment or with transport, must be solved beforehand in order to avoid unacceptable delays and extra costs during the installation. Experience gained with LEP has already shown the help that Computer-Aided Engineering tools could provide for the integration. A virtual model of the LHC is presently prepared. The actual LEP tunnel, known with a quite good accuracy (centimetre level), has been modelled and all the elements of the machine constructed as 3D objects with the CAD system are positioned accurately on the basis of data generated from the theoretical definition. These layouts are used to generate the refe...

Magnet R and D for the US LHC Accelerator Research Program (LARP)

International Nuclear Information System (INIS)

Gourlay, S.A.; Ambrosio, G.; Andreev, N.; Anerella, M.; Barzi, E.; Bossert, R.; Caspi, S.; Dietderich, D.R.; Ferracin, P.; Gupta, R.; Ghosh, A.; Hafalia, A.R.; Hannaford, C.R.; Harrison, M.; Kashikhin, V.S.; Kashikhin, V.V.; Lietzke, A.F.; Mattafirri, S.; McInturff, A.D.; Nobrega, F.; Novitsky, I.; Sabbi, G.L.; Schmazle, J.; Stanek, R.; Turrioni, D.; Wanderer, P.; Yamada, R.; Zlobin, A.V.

2006-01-01

In 2004, the US DOE established the LHC Accelerator Research Program (LARP) with the goal of developing a technology base for future upgrades of the LHC. The focus of the magnet program, which is a collaboration of three US laboratories, BNL, FNAL and LBNL, is on development of high gradient quadrupoles using Nb 3 Sn superconductor. Other program components address issues regarding magnet design, radiation-hard materials, long magnet scale-up, quench protection, fabrication techniques and conductor and cable R and D. This paper presents an overall view of the program with emphasis on the current quadrupole project and outlines the long-term goals of the program

Radioactive airborne species formed in the air in high energy accelerator tunnels

International Nuclear Information System (INIS)

Kondo, K.

2005-01-01

Many radioactive airborne species have been observed in the air of high energy accelerator tunnels during machine operation. Radiation protection against these induced airborne radioactivities is one of the key issues for radiation safety, especially at high-energy and high-intense proton accelerators such as the J-PARC (Japan Proton Accelerator Research Complex, Joint project of KEK and JAERI), which is now under construction at the TOKAI site of JAERI. Information on the chemical forms and particle sizes of airborne radioactivities is essential for the estimation of internal doses. For that purpose, the study on radioactive airborne species formed in the air of beam-line tunnels at high-energy accelerators have been extensively conducted by our group. For Be-7, Na-24, S-38, Cl-38,-39, C-11, and N-13, formed by various types of nuclear reactions including nuclear spallation reactions, their aerosol and gaseous fractions are determined by a filter technique. A parallel plate diffusion battery is used for the measurement of aerosol size distributions, and the formation of radioactive aerosols is explained by the attachment of radionuclides to ambient non-radioactive aerosols which are formed through radiation induced reactions. The chemical forms of gaseous species are also determined by using a selective collection method based on a filter technique. A review is given of the physico-chemical properties of these airborne radionuclides produced in the air of accelerator beam-line tunnels.

Radiation tolerance assurance of technical equipment in the LHC radiation monitoring for technical equipment at the LHC

CERN Document Server

Wijnands, Thijs; CERN. Geneva. TS Department

2005-01-01

In contrast with other accelerators at CERN, a large amount of technical equipment will be located in the LHC tunnel, the underground areas and in the experimental caverns where they will be exposed to radiation. Nearly all this equipment makes, to a certain extent, use of commercial microelectronics which is extremely sensitive to radiation damage, both instantaneous damage and cumulative damage. Examples in the TS Department are the electronics for the position sensors of the low beta quadrupoles, the access system, the cooling and ventilation units, the electronics for the electrical distribution, the oxygen deficiency monitors and fire detection systems. The basic effects of radiation on electronic systems and components are well understood because similar problems with radiation are encountered in the aerospace and aviation industry. Since 1998, an efficient and original Radiation Tolerance Assurance approach for the LHC machine has been established. Its aim is to minimise the effects of radiation damage...

Handling and Transport of Oversized Accelerator Components and Physics Detectors

CERN Document Server

Prodon, S; Guinchard, M; Minginette, P

2006-01-01

For cost, planning and organisational reasons, it is often decided to install large pre-built accelerators components and physics detectors. As a result surface exceptional transports are required from the construction to the installation sites. Such heavy transports have been numerous during the LHC installation phase. This paper will describe the different types of transport techniques used to fit the particularities of accelerators and detectors components (weight, height, acceleration, planarity) as well as the measurement techniques for monitoring and the logistical aspects (organisation with the police, obstacles on the roads, etc). As far as oversized equipment is concerned, the lowering into the pit is challenging, as well as the transport in tunnel galleries in a very scare space and without handling means attached to the structure like overhead travelling cranes. From the PS accelerator to the LHC, handling systems have been developed at CERN to fit with these particular working conditions. This pap...

18 January 2011 - The British Royal Academy of Engineering in the LHC tunnel with CMS Collaboration Spokesperson G. Tonelli and Beams Department Head P. Collier; in the CERN Control Centre with P. Collier and LHC superconducting magnet test hall with Technology Department Head F. Bordry.

CERN Multimedia

Jean-Claude Gadmer

2011-01-01

18 January 2011 - The British Royal Academy of Engineering in the LHC tunnel with CMS Collaboration Spokesperson G. Tonelli and Beams Department Head P. Collier; in the CERN Control Centre with P. Collier and LHC superconducting magnet test hall with Technology Department Head F. Bordry.

Fast Automatic Beam-Based Alignment of the LHC Collimator Jaws

CERN Document Server

AUTHOR|(CDS)2080813; Assmann, R W

2014-01-01

The CERN Large Hadron Collider (LHC) in Geneva, Switzerland is the largest and most powerful particle accelerator ever built. With a circumference of 27 km, it is designed to collide particles in two counter-rotating beams at a centre-of-mass energy of 14 TeV to explore the fundamental forces and constituents of matter. Due to its potentially destructive high energy particle beams, the LHC is equipped with several machine protection systems. The LHC collimation system is tasked with scattering and absorbing beam halo particles before they can quench the superconducting magnets. The 108 collimators also protect the machine from damage in the event of very fast beam losses, and shields sensitive devices in the tunnel from radiation over years of operation. Each collimator is made up of two blocks or ‘jaws’ of carbon, tungsten or copper material. The collimator jaws need be placed symmetrically on either side of the beam trajectory, to clean halo particles with maximum efficiency. The beam orbit and beam siz...

Steel septum magnets for the LHC beam injection and extraction

CERN Document Server

Bidon, S; Guinand, M; Gyr, Marcel; Sassowsky, M; Weisse, E; Weterings, W; Abramov, A; Ivanenko, A I; Kolatcheva, E; Lapyguina, O; Ludmirsky, E; Mishina, N; Podlesny, P; Riabov, A; Tyurin, N

2002-01-01

The Large Hadron Collider (LHC) will be a superconducting accelerator and collider to be installed in the existing underground LEP ring tunnel at CERN. It will provide proton-proton collisions with a centre of mass energy of 14 TeV. The proton beams coming from the SPS will be injected into the LHC at 450 GeV by vertically deflecting kicker magnets and horizontally deflecting steel septum magnets (MSI). The proton beams will be dumped from the LHC with the help of two extraction systems comprising horizontally deflecting kicker magnets and vertically deflecting steel septum magnets (MSD). The MSI and MSD septa are laminated iron-dominated magnets using an all welded construction. The yokes are constructed from two different half cores, called coil core and septum core. The septum cores comprise circular holes for the circulating beams. This avoids the need for careful alignment of the usually wedge-shaped septum blades used in classical Lambertson magnets. The MSI and MSD septum magnets were designed and buil...

Superconducting link bus design for the accelerator project for upgrade of LHC

International Nuclear Information System (INIS)

Nobrega, F.; Brandt, J.; Cheban, S.; Feher, S.; Kaducak, M.; Kashikhin, V.; Peterson, T.

2011-01-01

The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. Fermi National Accelerator Laboratory in collaboration with Brookhaven National Laboratory was developing sub-systems for the upgrade of the LHC final focus magnet systems. Part of the upgrade called for various lengths of superconducting power transmission lines known as SC Links which were up to 100 m long. The SC Link electrically connects the current leads in the Distribution Feed Boxes to the interaction region magnets. The SC Link is an extension of the magnet bus housed within a cryostat. The present concept for the bus consists of 22 power cables, 4 x 13 kA, 2 x 7 kA, 8 x 2.5 kA and 8 x 0.6 kA bundled into one bus. Different cable and strand possibilities were considered for the bus design including Rutherford cable. The Rutherford cable bus design potentially would have required splices at each sharp elbow in the SC Link. The advantage of the round bus design is that splices are only required at each end of the bus during installation at CERN. The round bus is very flexible and is suitable for pulling through the cryostat. Development of the round bus prototype and of 2 splice designs is described in this paper. Magnetic analysis and mechanical test results of the 13 kA cable and splices are presented.

SEU tests performed on the digital communication system for LHC cryogenic instrumentation

International Nuclear Information System (INIS)

Casas-Cubillos, J.; Faccio, F.; Gomes, P.; Martin, M.A.; Rodriguez-Ruiz, M.A.

2002-01-01

The future LHC particle accelerator will use a large number of cryogenic sensors and actuators, most of which are located inside the machine tunnel and therefore in a radiation environment. These elements will communicate through a fieldbus. This paper reports the irradiation study carried out on WorldFIP fieldbus communication system. A digital communication system based on WorldFIP fieldbus protocol has been implemented and single event effects and total ionizing dose radiation tests have been performed on it

Installation of the LHC transfer lines begins

CERN Multimedia

Patrice Loïez

2003-01-01

The first of 700 magnets has been installed in one of the two transfer tunnels built to transfer the SPS beam into the LHC. The start of this first installation phase of the LHC transfer lines provides the opportunity to launch a new and highly original modular system for transporting and installing all kinds of magnets in very narrow tunnels. The system is based on very compact bogies, up to four of which can be coupled together to form a convoy. The wheels are fitted with individual motors enabling them to swivel through an angle of 90° and the convoy to move laterally. In this way the magnet is delivered directly to its installation point, but beneath the beamline. It is then raised into its final position in the beamline using air cushions, which form an integrated part of the transport system.Photos 01, 02: Pictured with the newly installed magnet and transport system in the transfer line tunnel are LHC project leader Lyn Evans (second left, white helmet); Volker Mertens, responsible for the LHC injecti...

Installation of the LHC transfer lines begins

CERN Multimedia

Patrice Loïez

2003-01-01

The first of 700 magnets has been installed in one of the two transfer tunnels built to transfer the SPS beam into the LHC. The start of this first installation phase of the LHC transfer lines provides the opportunity to launch a new and highly original modular system for transporting and installing all kinds of magnets in very narrow tunnels. The system is based on very compact bogies, up to four of which can be coupled together to form a convoy. The wheels are fitted with individual motors enabling them to swivel through an angle of 90° and the convoy to move laterally. The first installation phase will continue until mid-April. In addition to the magnets, a beam dump facility also has to be installed. The second installation phase will take place later this year and should be completed in 2004, when the TI 8 transfer line is due to be tested. The second transfer line, in tunnel TI 2, should be ready in April 2007, once the LHC magnets have been transported through the downstream section of this tunnel.Pho...

Installation of the LHC transfer lines begins

CERN Multimedia

Patrice Loïez

2003-01-01

The first of 700 magnets has been installed in one of the two transfer tunnels built to transfer the SPS beam into the LHC. The start of this first installation phase of the LHC transfer lines provides the opportunity to launch a new and highly original modular system for transporting and installing all kinds of magnets in very narrow tunnels. The system is based on very compact bogies, up to four of which can be coupled together to form a convoy. The wheels are fitted with individual motors enabling them to swivel through an angle of 90° and the convoy to move laterally. The first installation phase will continue until mid-April. In addition to the magnets, a beam dump facility also has to be installed. The second installation phase will take place later this year and should be completed in 2004, when the TI 8 transfer line is due to be tested. The second transfer line, in tunnel TI 2, should be ready in April 2007, once the LHC magnets have been transported through the downstream section of this tunnel. Th...

Installation of the LHC transfer lines begins

CERN Multimedia

Patrice Loïez

2003-01-01

The first of 700 magnets has been installed in one of the two transfer tunnels built to transfer the SPS beam into the LHC. The start of this first installation phase of the LHC transfer lines provides the opportunity to launch a new and highly original modular system for transporting and installing all kinds of magnets in very narrow tunnels. The system is based on very compact bogies, up to four of which can be coupled together to form a convoy. The wheels are fitted with individual motors enabling them to swivel through an angle of 90° and the convoy to move laterally. The first installation phase will continue until mid-April. In addition to the magnets, a beam dump facility also has to be installed. The second installation phase will take place later this year and should be completed in 2004, when the TI 8 transfer line is due to be tested. The second transfer line, in tunnel TI 2, should be ready in April 2007, once the LHC magnets have been transported through the downstream section of this tunnel. We...

LHC magnets

International Nuclear Information System (INIS)

Anon.

1992-01-01

Preparations for the LHC proton collider to be built in CERN's LEP tunnel continue to make good progress. In particular development work for the high field superconducting magnets to guide the almost 8 TeVproton beams through the 'tight' curve of the 27-kilometre ring are proceeding well, while the magnet designs and lattice configuration are evolving in the light of ongoing experience. At the Evian LHC Experiments meeting, this progress was covered by Giorgio Brianti

Engineers win award for Swiss tunnel

CERN Multimedia

2003-01-01

A Derby engineering consultancy has won the Tunnelling Industry Award 2003 for Excellence in Tunnel Design, offered by the British Tunnelling Society, for its work on the LHC in Geneva, Switzerland (1/2 page).

Co-operation Agreement relating to LHC Commissioning

CERN Multimedia

2005-01-01

CERN Director-General Robert Aymar and Ryszard Tadeusiewicz, the Rector of the AGH University of Science and Technology in Cracow, after signing the agreement. On 29 July, the Rector of the AGH University of Science and Technology in Cracow, Ryszard Tadeusiewicz, and CERN Director-General Robert Aymar signed a collaboration agreement relating to the commissioning of the instrumentation and monitoring equipment for the LHC cryogenic system. Under the agreement, a team consisting of a dozen physicists, engineers and technicians from the AGH University in Cracow will lend a helping hand to the teams at CERN for the commissioning of the cryogenic system in the tunnel. This is the first in what will be a series of agreements relating to the commissioning of the LHC's various systems. From the end of this year until the summer of 2007, CERN will require reinforcements of physicists, engineers and technicians in order to complete the many tasks associated with the start-up of the accelerator. CERN is therefore pre...

Wall-Current-Monitor based Ghost and Satellite Bunch Detection in the CERN PS and the LHC Accelerators

CERN Document Server

Steinhagen, R J; Belleman, J; Bohl, T; Damerau, H

2012-01-01

While most LHC detectors and instrumentation systems are optimised for a nominal bunch spacing of 25 ns, the LHC RF cavities themselves operate at the 10th harmonic of the maximum bunch frequency. Due to the beam production scheme and transfers in the injector chain, part of the nominally ‘empty’ RF buckets may contain particles, referred to as ghost or satellite bunches. These populations must be accurately quantified for high-precision experiments, luminosity calibration and control of parasitic particle encounters at the four LHC interaction points. This contribution summarises the wall-current-monitor based ghost and satellite bunch measurements in CERN’s PS and LHC accelerators. Instrumentation set-up, post-processing and achieved performance are discussed.

LHC synchronization test successful

CERN Multimedia

The synchronization of the LHC's clockwise beam transfer system and the rest of CERN's accelerator chain was successfully achieved last weekend. Tests began on Friday 8 August when a single bunch of a few particles was taken down the transfer line from the SPS accelerator to the LHC. After a period of optimization, one bunch was kicked up from the transfer line into the LHC beam pipe and steered about 3 kilometres around the LHC itself on the first attempt. On Saturday, the test was repeated several times to optimize the transfer before the operations group handed the machine back for hardware commissioning to resume on Sunday. The anti-clockwise synchronization systems will be tested over the weekend of 22 August.Picture:http://lhc-injection-test.web.cern.ch/lhc-injection-test/

Development of the System Test for the LHC Tune Measurement and Abort Gap Monitoring

CERN Document Server

Beccati, B

2008-01-01

The Large Hadron Collider (LHC) is the largest accelerator in the world and it will collide opposing beams of 7 TV protons together. It is built inside a 27km tunnel on the border between France and Switzerland. Within the framework of the project IUSS- Ferrara, I collaborated with the members of the AB-BI section at CERN: Accelerator Beam - Beam Instrumentation. My degree thesis is the result of this cooperation. My project is made of two sections, one for each themes analyzed during this year at CERN: the first one concerns the Tune, the second one is about the Abort gap. LHC is a synchrotron, an accelerator using dipole magnets to bending and quadrupole magnets to transverse focusing. Passing through this pattern of magnets, particles make oscillations. We refer to these ones as Betatron oscillations. The number of such oscillations/turn is called Tune. The ability tomeasure the tune is important for many kinds of diagnostic. In the base band tune (BBQ) measurement system developed at CERN the signal is di...

Design approach for the development of a cryomodule for compact crab cavities for Hi-Lumi LHC

Science.gov (United States)

Pattalwar, Shrikant; Jones, Thomas; Templeton, Niklas; Goudket, Philippe; McIntosh, Peter; Wheelhouse, Alan; Burt, Graeme; Hall, Ben; Wright, Loren; Peterson, Tom

2014-01-01

A prototype Superconducting RF (SRF) cryomodule, comprising multiple compact crab cavities is foreseen to realise a local crab crossing scheme for the "Hi-Lumi LHC", a project launched by CERN to increase the luminosity performance of LHC. A cryomodule with two cavities will be initially installed and tested on the SPS drive accelerator at CERN to evaluate performance with high-intensity proton beams. A series of boundary conditions influence the design of the cryomodule prototype, arising from; the complexity of the cavity design, the requirement for multiple RF couplers, the close proximity to the second LHC beam pipe and the tight space constraints in the SPS and LHC tunnels. As a result, the design of the helium vessel and the cryomodule has become extremely challenging. This paper assesses some of the critical cryogenic and engineering design requirements and describes an optimised cryomodule solution for the evaluation tests on SPS.

The HL-LHC accelerator physics challenges

CERN Document Server

Fartoukh, S

2014-01-01

We review the conceptual baseline of the HL-LHC project, putting into perspective the main beam physics challenges of this new collider in comparison with the existing LHC, and the series of solutions and possible mitigation measures presently envisaged.

The HL-LHC Accelerator Physics Challenges

Science.gov (United States)

Fartoukh, S.; Zimmermann, F.

The conceptual baseline of the HL-LHC project is reviewed, putting into perspective the main beam physics challenges of this new collider in comparison with the existing LHC, and the series of solutions and possible mitigation measures presently envisaged.

The HL-LHC accelerator physics challenges

CERN Document Server

Fartoukh, S

2015-01-01

The conceptual baseline of the HL-LHC project is reviewed, putting into perspective the main beam physics challenges of this new collider in comparison with the existing LHC, and the series of solutions and possible mitigation measures presently envisaged.

The LHC magnets' trip underground

CERN Multimedia

2002-01-01

Buildings SMI 2 and SDI 2 are currently a big blue construction at the end of the Meyrin site. When they are finished, in 2003, they will be the departure point from where the magnets for the LHC will be lowered down into the tunnel. View of the new building at the end of the Meyrin site. If you live in neighbouring France, you have probably noticed a new blue steel construction that has changed the view from Saint Genis Pouilly since last March. It's the first of two contiguous buildings, SMI 2 and SDI 2, which will make it possible to prepare and lower the 1232 dipole magnets, the 400 short straight sections and some 60 insertion magnets down into the TI2 tunnel, and from there, to their final location in the LHC tunnel. According to Paul Faugeras, Technical Co-ordinator for the LHC machine, 'the installation of the magnets will start in early 2004, and hopefully everything will be done by October 2006'. The first part of the magnets' journey will take place on surface. The 15 metre-long dipole magnets a...

Precision transport of LHC superconducting magnet

CERN Multimedia

Maximilien Brice

2003-01-01

These photos show tests of the first convoy with a prototype short straight section (SSS) quadrupole in the LHC tunnel. There is little free space in the tunnel as the SSS convoy passes alongside a dipole vacuum vessel. These convoys feature infrared guidance, which offsets the minimal clearance in the tunnel and limits vibration, both of which could damage the fragile magnets.

Protons on the doorstep of the LHC

CERN Multimedia

Mertens, Volker

2005-01-01

The first of the two new beam transfer lines to the LHC was successfully commissioned in autumn 2004. At the first attempt a low-intensity proton beam passed down the line to a few meters before the LHC tunnel (3 pages)

Successful test of SPS-to-LHC beamline

CERN Multimedia

Maximilien Brice

2004-01-01

On 23 October there was great excitement in the Prevessin control room when, on the first attempt, a beam passed over 2.5 km down the new SPS-to-LHC transfer line, TI8, to within a few metres of the LHC tunnel.

Some of the QRL team in UJ22 of the LHC tunnel, where the last sector of the cryogenic distribution line was installed.

CERN Multimedia

Viviane Li

2006-01-01

The cryogenic distribution line "the QRL" is a circle built in 8 sectors, each approximately 3 km in length. It will circulate helium in liquid and gas phases, at different temperatures and pressures, to provide the cryogenic conditions for the superconducting magnets in the LHC tunnel.

Restart of the LHC. CERN and the accelerators. The world machine illustratively explained; Neustart des LHC. CERN und die Beschleuniger. Die Weltmaschine anschaulich erklaert

Energy Technology Data Exchange (ETDEWEB)

Hauschild, Michael

2016-07-01

The following topics are dealt with: The development of the European research center for particle physics CERN, the standard model of elementary-particle physics, the detection of the W and Z bosons with the SPS collider, the principles of particle accelerators, the way to the LHC. (HSI)

Commissioning of the LHC Cryogenic System Subsystems Cold Commissioning in Preparation of Full Sector Tests

CERN Document Server

Serio, L; Ferlin, G; Gilbert, N; Gruehagen, Henning; Knoops, S; Parente, C; Sanmartí, M

2006-01-01

The cryogenic system for the Large Hadron Collider accelerator is presently in its final phase of installation and commissioning at nominal operating temperatures. The refrigeration capacity for the LHC will be produced using eight large cryogenic plants installed on five technical sites and distributed around the 26.7-km circumference ring located in a deep underground tunnel. The status of the cryogenic system commissioning is presented together with the experience gained in operating and commissioning it.

Installation of the LHC transfer lines begins

CERN Multimedia

Patrice Loïez

2003-01-01

The first of 700 magnets has been installed in one of the two transfer tunnels built to transfer the SPS beam into the LHC. The start of this first installation phase of the LHC transfer lines provides the opportunity to launch a new and highly original modular system for transporting and installing all kinds of magnets in very narrow tunnels. The system is based on very compact bogies, up to four of which can be coupled together to form a convoy. The wheels are fitted with individual motors enabling them to swivel through an angle of 90° and the convoy to move laterally. In this way the magnet is delivered directly to its installation point, but beneath the beamline. It is then raised into its final position in the beamline using air cushions, which form an integrated part of the transport system.Photo 01: Pictured with the newly installed magnet and transport system in the transfer line tunnel are (left to right) Volker Mertens, responsible for the LHC injection and transfer lines; personnel involved in tr...

Robert Aymar seals the last interconnect in the LHC

CERN Multimedia

Maximilien Brice

2007-01-01

The LHC completes the circle. On 7 November, in a brief ceremony in the LHC tunnel, CERN Director General Robert Aymar (Photo 1) sealed the last interconnect between the main magnets of the Large Hadron Collider (LHC). Jean-Philippe Tock, leader of the Interconnections team, tightens the last bolt (Photos 4-8).

Quench simulations for superconducting elements in the LHC accelerator

Science.gov (United States)

Sonnemann, F.; Schmidt, R.

2000-08-01

The design of the protection system for the superconducting elements in an accelerator such as the large Hadron collider (LHC), now under construction at CERN, requires a detailed understanding of the thermo-hydraulic and electrodynamic processes during a quench. A numerical program (SPQR - simulation program for quench research) has been developed to evaluate temperature and voltage distributions during a quench as a function of space and time. The quench process is simulated by approximating the heat balance equation with the finite difference method in presence of variable cooling and powering conditions. The simulation predicts quench propagation along a superconducting cable, forced quenching with heaters, impact of eddy currents induced by a magnetic field change, and heat transfer through an insulation layer into helium, an adjacent conductor or other material. The simulation studies allowed a better understanding of experimental quench data and were used for determining the adequate dimensioning and protection of the highly stabilised superconducting cables for connecting magnets (busbars), optimising the quench heater strip layout for the main magnets, and studying quench back by induced eddy currents in the superconductor. After the introduction of the theoretical approach, some applications of the simulation model for the LHC dipole and corrector magnets are presented and the outcome of the studies is compared with experimental data.

Strategy and issues for the LHC upgrades and fair, including longer-term prospects

CERN Document Server

Zimmermann, F

2013-01-01

This report discusses the time line, goals and key ingredients for the next ten years of LHC operation, including injector upgrade, for the following High Luminosity LHC (HL-LHC), and for the FAIR project. Results from pertinent EuCARD-WP4 workshops on optics, space charge, crab cavities, crystal collimation, and electron cloud are summarized in this context. A Large Hadron electron Collider, LHeC, would be an additional upgrade, further expanding the physics scope of the LHC, to eventually include both ep and γγ Higgs factories (LHeC-HF and SAPPHiRE). Results from relevant topical WP4 workshops are highlighted. The development of magnet and cable technology based on Nb$_{3}$Sn, and HTS, for the HL-LHC prepares the ground for a future higher-energy hadron collider, either in the LHC tunnel, “HELHC” (33 TeV c.m.), or in a new 80- or 100-km tunnel, “VHE-LHC” (100 TeV c.m.). A large new tunnel could also host an ultimate highest-precision e+e- Higgs factory collider, “TLEP,” exhibiting many synergi...

The last LHC dipole magnet is lowered

CERN Multimedia

Claudia Marcelloni

2007-01-01

A ceremony is held as the last of 1746 superconducting magnets is lowered into the 27-km circumference tunnel that houses the LHC. The LHC project leader, Lyn Evans, changes a banner reading ‘first magnet for the LHC’ to ‘last magnet for the LHC’ in his native Welsh.

LHC milestone

International Nuclear Information System (INIS)

Anon.

1992-01-01

At the December meeting of CERN's Council, the Organization's Governing Body, the delegates from the 16 Member States unanimously agreed that the LHC proton-proton collider proposed for the 27-kilometre LEP tunnel is the 'right machine for the advance of the subject and of the future of CERN'

Successful test of SPS-to-LHC beamline

CERN Multimedia

Maximilien Brice

2004-01-01

On 23 October there was great excitement in the Prevessin control room when, on the first attempt, a beam passed over 2.5 km down the new SPS-to-LHC transfer line, TI8, to within a few metres of the LHC tunnel. Members of the AB, AT and TS departments involved in the beamline and its test, celebrate their success with the Director General, Robert Aymar, and the LHC Project Leader, Lyn Evans.

Successful test of SPS-to-LHC beamline

CERN Multimedia

2004-01-01

On 23 October there was great excitement in the Prevessin control room when, on the first attempt, a beam passed over 2.5 km down the new SPS-to-LHC transfer line, TI8, to within a few metres of the LHC tunnel. Above: members of the AB, AT and TS departments involved in the beamline and its test, celebrate their success with the Director General, Robert Aymar, and the LHC Project Leader, Lyn Evans.

Energy Deposition and DPA in the Superconducting Links for the HILUMI LHC Project at the LHC Interaction Points

CERN Document Server

AUTHOR|(CDS)2092158; Broggi, Francesco; Santini, C; Ballarino, Amalia; Cerutti, Francesco; Esposito, Luigi Salvatore

2015-01-01

In the framework of the upgrade of the LHC machine, the powering of the LHC magnets foresees the removal of the power converters and distribution feedboxes from the tunnel and its location at the surface[1]. The Magnesium Diboride (MgB2) connecting lines in the tunnel will be exposed to the debris from 7+7 TeV p-p interaction. The Superconducting (SC) Links will arrive from the surface to the tunnel near the separation dipole, at about 80 m from the Interaction Point at IP1 and IP5. The Connection Box (where the cables of the SC Links are connected to the NbTi bus bar) will be close to the beam pipe. The debris and its effect on the MgB2 SC links in the connection box (energy deposition and displacement per atom) are presented. The effect of thermal neutrons on the Boron consumption and the contribution of the lithium nucleus and the alpha particle on the DPA are evaluated. The results are normalized to an integrated luminosity of 3000 fb-1, value that represents the LHC High Luminosity lifetime. The dose de...

Installation of the LHC transfer lines begins

CERN Multimedia

2003-01-01

On 19 February, the very first magnet was installed in one of the two tunnels that will house the transfer lines leading to the LHC. This magnet, recycled from a previous facility, was transported and positioned using a novel system designed for conveying large objects through narrow tunnels.

Installation and Quality Assurance of the Interconnections between Cryo-assemblies of the LHC Long Straight Sections

CERN Document Server

Garion, C; Tock, J P

2006-01-01

The interconnections between the cryomagnets and cryogenic utilities in the LHC long Straight Sections constitute the last machine installation activity. They are ensuring continuity of the beam and insulation vacuum systems, cryogenic fluid and electrical circuits and thermal insulation. The assembly is carried out in a constraining tunnel environment with restricted space. Therefore, the assembly sequence has to be well defined and specific tests have to be performed during the interconnection work to secure the reliability of the system and thus to ensure the global accelerator availability. The LHC has 8 long straight insertion zones composed of special cryomagnets involving specific interconnection procedures and QA plans. The aim of this paper is to present the installation and quality assurance procedures implemented for the LHC LSS interconnections. Technologies such as manual and automatic welding and resistive soldering will be described as well as the different quality controls, such as visual and ...

The LHC's equipment all in step

CERN Multimedia

2005-01-01

Over 80% of the control equipment for the LHC will be connected by a special communication network known as WorldFIP, which has been chosen for its very precise timing, excellent operating performance and robustness in difficult environments. Over 350 kilometres of this network are currently being installed in the LHC tunnel and checked for compliance with the required standards.

CERN: LHC progress

International Nuclear Information System (INIS)

Anon.

1993-01-01

The push for CERN's next major project, the LHC proton collider to be built in the 27-kilometre LEP tunnel, is advancing on a wide front. For the machine itself, there has been considerable progress in the detailed design. While the main thrust is for proton-proton collisions, heavy ions are also on the LHC collision menu. On the experimental side, proposals are coming into sharper focus. For the machine, the main aim is for the highest possible proton collision energies and collision rates in the confines of the existing LEP tunnel, and the original base design looked to achieve these goals in three collision regions. Early discussions on the experimental programme quickly established that the most probable configuration would have two collision regions rather than three. This, combined with hints that the electronics of several detectors would have to handle several bunch crossings at a time, raised the question whether the originally specified bunch spacing of 15 ns was still optimal

Considerations on Energy Frontier Colliders after LHC

Energy Technology Data Exchange (ETDEWEB)

Shiltsev, Vladimir [Fermilab

2016-11-15

Since 1960’s, particle colliders have been in the forefront of particle physics, 29 total have been built and operated, 7 are in operation now. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). The future of the world-wide HEP community critically depends on the feasibility of possible post-LHC colliders. The concept of the feasibility is complex and includes at least three factors: feasibility of energy, feasibility of luminosity and feasibility of cost. Here we overview all current options for post-LHC colliders from such perspective (ILC, CLIC, Muon Collider, plasma colliders, CEPC, FCC, HE-LHC) and discuss major challenges and accelerator R&D required to demonstrate feasibility of an energy frontier accelerator facility following the LHC. We conclude by taking a look into ultimate energy reach accelerators based on plasmas and crystals, and discussion on the perspectives for the far future of the accelerator-based particle physics. This paper largely follows previous study [1] and the presenta ion given at the ICHEP’2016 conference in Chicago [2].

LHC status report

CERN Multimedia

CERN Bulletin

2010-01-01

Following the great success of the first 3.5 TeV collisions in all four LHC experiments on 30 March, the focus of the LHC commissioning teams has turned to consolidating the beam injection and acceleration procedures.   During the last two weeks, the operators have adopted a cycle of beam commissioning studies by day and the preparation and delivery of collisions during the night shifts. The injection and acceleration processes for the beams are by now well established and almost all feedback systems, which are an essential ingredient for establishing reliable and safe machine operation, have been commissioned. Thanks to special current settings for the quadrupoles that are situated near the collision points, the LHC luminosity at high energy has been increased by a factor of 5 in three of the four experiments. Similar improvements are under way for the fourth experiment. The next steps include adjustments of the LHC machine protection and collimation devices, which will ensure 'stable beam' co...

Accelerator physics studies on the effects from an asynchronous beam dump onto the LHC experimental region collimators

CERN Document Server

Lari, L; Boccone, V; Bruce, R; Cerutti, F; Rossi, A; Vlachoudis, V; Mereghetti, A; Faus-Golfe, A

2012-01-01

Asynchronous beam aborts at the LHC are estimated to occur on average once per year. Accelerator physics studies of asynchronous dumps have been performed at different beam energies and beta-stars. The loss patterns are analyzed in order to identify the losses in particular on the Phase 1 Tertiary Collimators (TCT), since their tungsten-based active jaw insert has a lower damage threshold than the carbon-based other LHC collimators. Settings of the tilt angle of the TCTs are discussed with the aim of reducing the thermal loads on the TCT themselves.

LHC Supertable

International Nuclear Information System (INIS)

Pereira, M.; Lahey, T.E.; Lamont, M.; Mueller, G.J.; Teixeira, D.D.; McCrory, E.S.

2012-01-01

LHC operations generate enormous amounts of data. This data is being stored in many different databases. Hence, it is difficult for operators, physicists, engineers and management to have a clear view on the overall accelerator performance. Until recently the logging database, through its desktop interface TIMBER, was the only way of retrieving information on a fill-by-fill basis. The LHC Supertable has been developed to provide a summary of key LHC performance parameters in a clear, consistent and comprehensive format. The columns in this table represent main parameters that describe the collider operation such as luminosity, beam intensity, emittance, etc. The data is organized in a tabular fill-by-fill manner with different levels of detail. Particular emphasis was placed on data sharing by making data available in various open formats. Typically the contents are calculated for periods of time that map to the accelerator's states or beam modes such as Injection, Stable Beams, etc. Data retrieval and calculation is triggered automatically after the end of each fill. The LHC Supertable project currently publishes 80 columns of data on around 100 fills. (authors)

The whole world behind the LHC

CERN Multimedia

2001-01-01

The LHC Board, which includes representatives of the non-Member State organisations directly involved in the construction of the LHC accelerator and representatives of CERN, held its fourth meeting on Monday 21 May 2001. From left to right: 1st row, A. Yamamoto (KEK, Japan), P. Pfund (FNAL, United States), L. Maiani (CERN Director-General), L. Evans (LHC Project Leader), F. Dupont (IN2P3, France), D.D. Bhawalkar (CAT, India) ; 2nd row, P. Brossier (CEA, France), N. Tyurin (IHEP, Russia), A. Skrinsky (BINP, Russia), A. Astbury (TRIUMF, Canada), P. Lebrun (LHC Division Leader, CERN); 3rd row, T. Taylor (Deputy Division Leader LHC Division, CERN), A. Shotter (TRIUMF, Canada), P. Bryant (LHC, CERN), K. Hübner (Director for Accelerators, CERN), J. van der Boon (Director of Administration, CERN). Although Canada, the United States, India, Japan and the Russian Federation are not members of CERN, they are all playing an active part in the construction of the LHC through important technical and financial co...

The High Luminosity LHC Project

Science.gov (United States)

Rossi, Lucio

The High Luminosity LHC is one of the major scientific project of the next decade. It aims at increasing the luminosity reach of LHC by a factor five for peak luminosity and a factor ten in integrated luminosity. The project, now fully approved and funded, will be finished in ten years and will prolong the life of LHC until 2035-2040. It implies deep modifications of the LHC for about 1.2 km around the high luminosity insertions of ATLAS and CMS and relies on new cutting edge technologies. We are developing new advanced superconducting magnets capable of reaching 12 T field; superconducting RF crab cavities capable to rotate the beams with great accuracy; 100 kA and hundred meter long superconducting links for removing the power converter out of the tunnel; new collimator concepts, etc... Beside the important physics goals, the High Luminosity LHC project is an ideal test bed for new technologies for the next hadron collider for the post-LHC era.

LHC magnet string in 1994

CERN Multimedia

1994-01-01

On 6-7 December 1994, a string of powerful superconducting magnets for CERN's next particle accelerator, the Large Hadron Collider (LHC), ran successfully at 8.36 tesla for 24 hours. This magnetic field is 100 000 times that of the Earth and is required to keep beams of protons travelling on the correct circular path over 27 km at 7 TeV in the new LHC accelerator.

An intelligent and networking solution of radiation monitoring system for LHC

International Nuclear Information System (INIS)

Shao Beibei; Gong Guanghua

2001-01-01

The LHC (the Large Hadron Collider), the largest accelerator in the world, is under designing and construction at CERN. It shares the 27 km LEP tunnel and is expected to be on the air in 2005. The Radiation Monitoring System of LEP was a central system with non-intelligent detectors. While as the proposed new RMS for LHC is a distributing intelligent networked system. Around 350 detectors will be employed. To save the cost, the design should make the old LEP's non-intelligent detectors reusable. To allow the detector controller automatic reports the detector database and net location through the world Fip bus, 1 wire components are embedded into the detectors and the network sockets. The radiation tolerance and the reliability of the communication of the wire components have been tested in a strong radiation field at CERN. The low cost components based position detection technique is valuable for most networked control system

End of the road for the LHC magnets...well, above ground that is!

CERN Multimedia

2003-01-01

The first LHC dipole cryomagnet has been delivered to the SMI2 building for final assembly prior to lowering it into the LHC tunnel. Over the next 3 years, all LHC cryomagnets will pass through these doors before starting their journey underground.

Beam-gas Background Observations at LHC

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00214737; The ATLAS collaboration; Alici, Andrea; Lazic, Dragoslav-Laza; Alemany Fernandez, Reyes; Alessio, Federico; Bregliozzi, Giuseppe; Burkhardt, Helmut; Corti, Gloria; Guthoff, Moritz; Manousos, Athanasios; Sjoebaek, Kyrre; D'Auria, Saverio

2017-01-01

Observations of beam-induced background at LHC during 2015 and 2016 are presented in this paper. The four LHC experiments use the non-colliding bunches present in the physics-filling pattern of the accelerator to trigger on beam-gas interactions. During luminosity production the LHC experiments record the beam-gas interactions using dedicated background monitors. These data are sent to the LHC control system and are used to monitor the background levels at the experiments during accelerator operation. This is a very important measurement, since poor beam-induced background conditions can seriously affect the performance of the detectors. A summary of the evolution of the background levels during 2015 and 2016 is given in these proceedings.

28th January 2011-Vice-President Max Planck Society-Prof. Martin Stratmann-Germany-visiting the ATLAS experimental area and the LHC Tunnel at CERN

CERN Multimedia

Jean-Claude Gadmer

2011-01-01

Photo 1:ATLAS visitor Center with P. Jenni, ATLAS Collaboration former spokesperson Photo 2-10:visiting the ATLAS cavern Photo 10:D. Hoppe,P. Jenni,M. Stratmann,S. Bethke,S. Braun,D. Klammer Photo 11-15:visiting the LHC tunnel Photo 16-18:Signature of the Guest Book with S. Lettow,Director for Administration and General Infrastructure

Large-Scale Experimental and Numerical Study of Blast Acceleration Created by Close-In Buried Explosion on Underground Tunnel Lining

Directory of Open Access Journals (Sweden)

Mohamad Reza Soheyli

2016-01-01

Full Text Available Despite growing demands for structures in water transportation tunnels, underground installations, subsurface dams, and subterranean channels, there is limited field knowledge about the dynamic behavior of these structures in the face of near-fault earthquakes or impulse excitations. This study conducted a large-scale test on underground tunnel excited by two close-in subsurface explosions. The horizontal and vertical acceleration were recorded on the vertical wall of the tunnel and the free field data including the acceleration on the ground surface at 11-meter distance from the tunnel. The frequency domain analysis of recorded results determined the frequency 961 Hz and 968 Hz for 1.69 kg and 2.76 kg equivalent T.N.T., respectively. Then, finite element analysis results were compared with the test data. The comparisons demonstrated a good correlation and satisfied the field data. Finally, based on numerical modeling, a parametric study was applied to determine the effects of shear wave velocity distance of the crater with respect to the tunnel on impulse response of the tunnel.

LHC superconducting strand

CERN Multimedia

Patrice Loiez

1999-01-01

This cross-section through a strand of superconducting matieral as used in the LHC shows the 8000 Niobium-Titanium filaments embedded like a honeycomb in copper. When cooled to 1.9 degrees above absolute zero in the LHC accelerator, these filaments will have zero resistance and so will carry a high electric current with no energy loss.

The LHC access system LACS and LASS

CERN Document Server

Ninin, P

2005-01-01

The LHC complex is divided into a number of zones with different levels of access controls.Inside the interlocked areas, the personnel protection is ensured by the LHC Access System.The system is made of two parts:the LHC Access Safety System and the LHC Access Control System. During machine operation,the LHC Access Safety System ensures the collective protection of the personnel against the radiation hazards arising from the operation of the accelerator by interlocking the LHC key safety elements. When the beams are off, the LHC Access Control System regulates the access to the accelerator and its many subsystems.It allows a remote, local or automatic operation of the access control equipment which verifies and identifies all users entering the controlled areas.The global architecture of the LHC Access System is now designed and is being validated to ensure that it meets the safety requirements for operation of the LHC.A pilot installation will be tested in the summer 2005 to validate the concept with the us...

Luminosity Optimization for a Higher-Energy LHC

CERN Document Server

Dominguez, O

2011-01-01

A Higher-Energy Large Hadron Collider (HE-LHC) is an option to further push the energy frontier of particle physics beyond the present LHC. A beam energy of 16.5 TeV would require 20 T dipole magnets in the existing LHC tunnel, which should be compared with 7 TeV and 8.33 T for the nominal LHC. Since the synchrotron radiation power increases with the fourth power of the energy, radiation damping becomes significant for the HE-LHC. It calls for transverse and longitudinal emittance control vis-a-vis beam-beam interaction and Landau damping. The heat load from synchrotron radiation, gas scattering, and electron cloud also increases with respect to the LHC. In this paper we discuss the proposed HE-LHC beam parameters; the time evolution of luminosity, beam-beam tune shifts, and emittances during an HE-LHC store; the expected heat load; and luminosity optimization schemes for both round and flat beams.

Golden Jubilee Photos: Laying the Ground for the LHC

CERN Multimedia

2004-01-01

In 1997, a prototype of the LHC dipole magnet, with the two beampipes running through the centre. Even before digging the LEP tunnel, in the early eighties CERN scientists began laying the plans for the second-generation collider to go in the tunnel. From the beginning, physicists had their eyes fixed on certain goals such as finding the Higgs boson and signs of supersymmetric particles. To reach the desired energies within the LEP tunnel, instead of LEP's electrons and positrons, the next collider would need to use more massive particles that radiate away less energy as they travel around the circular tunnel. Also, since the United States was planning the Superconducting Super Collider (SSC) with a circumference even larger than LEP's, CERN scientists conceived of their next collider as a "high-luminosity" machine that would excel at producing a high number of collisions. But since making a strong antiproton beam is laborious, this collider would have to smash together two proton beams. Thus the LHC project ...

Japanese contributions to CERN-LHC

International Nuclear Information System (INIS)

Kondo, Takahiko; Shintomi, Takakazu; Kimura, Yoshitaka

2001-01-01

The Large Hadron Collider (LHC) is now under construction at CERN, Geveva, to study frontier researches of particle physics. The LHC is the biggest superconducting accelerator using the most advanced cryogenics and applied superconductivities. The accelerator and large scale detectors for particle physics experiments are being constructed by collaboration with European countries and also by participation with non-CERN countries worldwide. In 1995, the Japanese government decided to take on a share in the LHC project with funding and technological contributions. KEK contributes to the development of low beta insertion superconducting quadrupole magnets and of components of the ATLAS detector by collaboration with university groups. Some Japanese companies have received contracts for technically key elements such as superconducting cable, cold compressor, nonmagnetic steel, polyimide film, and so on. An outline of the LHC project and Japanese contributions are described. (author)

The LHC road at CERN

International Nuclear Information System (INIS)

Anon.

1989-01-01

To explore the 1 TeV energy scale where fundamental particle interactions should encounter new conditions, two major routes were proposed - a high magnetic field proton collider in the LEP tunnel, dubbed LHC for Large Hadron Collider, and the CERN Linear Collider (CLIC) to supply beams of electrons and positrons. Exploratory studies have shown that while CLIC remains a valid long-term goal, LHC appears as the most cost-effective way for CERN to enter the 1 TeV arena. High-field superconducting magnet prototype work demonstrates that a 'two-in-one' design supplying the 10 tesla fields needed to handle LHC's 8 TeV proton beams (collision energy 16 TeV) is a practical proposition. (orig./HSI).

LHC magnets: the great descent

CERN Multimedia

2005-01-01

A first dipole magnet was delivered to its final location in the LHC tunnel on Monday, 7 March. This achievement coincides with another important milestone in the installation of the future collider, the completion of the delivery of half the dipole magnets.

HL-LHC alternatives

CERN Document Server

Tomás, R; White, S

2014-01-01

The HL-LHC parameters assume unexplored regimes for hadron colliders in various aspects of accelerator beam dynamics and technology. This paper reviews three alternatives that could potentially improve the LHC performance: (i) the alternative filling scheme 8b+4e, (ii) the use of a 200 MHz RF system in the LHC and (iii) the use of proton cooling methods to reduce the beam emittance (at top energy and at injection). The alternatives are assessed in terms of feasibility, pros and cons, risks versus benefits and the impact on beam availability.

The super-LHC

CERN Document Server

Mangano, Michelangelo L

2010-01-01

We review here the prospects of a long-term upgrade programme for the Large Hadron Collider (LHC), CERN laboratory's new proton-proton collider. The super-LHC, which is currently under evaluation and design, is expected to deliver of the order of ten times the statistics of the LHC. In addition to a non-technical summary of the principal physics arguments for the upgrade, I present a pedagogical introduction to the technological challenges on the accelerator and experimental fronts, and a review of the current status of the planning.

No access to LHC from 7 to 13 January 2008

CERN Multimedia

ST Department

2007-01-01

From 7 to 13 January 2008, tests of the LHC access system will be carried out to validate its role in the operational safety of the LHC. During this period, no access will be permitted to the controlled zones of LHC: service zones, experimental areas and tunnels. Access to the machine shafts and the tunnels will only be possible for emergency interventions coordinated with the CCC operators or for fire brigade interventions. The biometric access card integrated with the dosimeter, as issued by Bldg. 55, must be used to access these areas during this period. Access to the experimental caverns will be managed by the respective technical coordinator. After the tests, the access system will be restored to installation mode, i.e. access will again be possible using the CERN access cards for authorised personnel. Please communicate this information to your contractors. Thank you in advance for your comprehension and collaboration. Pierre Ninin - "LHC Access" project leader

Chasseurs de Higgs au LHC - A la Recherche des l'Origines

CERN Multimedia

Yves Sirois

To increase understanding of the LHC, why scientists collaborate on this experiment and what they hope to achieve with the LHC. A 51 slide presentation in French for a general audience. Delivered at the "Cité des Sciences" in Paris, "Rencontres du Ciel et de l'Espace," November, 2010 This presentation covers the following topics: - The LHC --what it is --what it looks like --where it is located --the international nature of CERN & experiment collaborations --the experiments - Accelerators --a brief history on accelerators --what accelerators can do - The scientific goals of the LHC - Particle Physics in General --history & the basics - Impact on Technology and Society - First LHC Results - Concluding remarks

High-field Magnet Development toward the High Luminosity LHC

Energy Technology Data Exchange (ETDEWEB)

Apollinari, Giorgio [Fermilab

2014-07-01

The upcoming Luminosity upgrade of the LHC (HL-LHC) will rely on the use of Accelerator Quality Nb3Sn Magnets which have been the focus of an intense R&D effort in the last decade. This contribution will describe the R&D and results of Nb3Sn Accelerator Quality High Field Magnets development efforts, with emphasis on the activities considered for the HL-LHC upgrades.

Commissioning of the 400 MHz LHC RF System

CERN Document Server

Ciapala, Edmond; Baudrenghien, P; Brunner, O; Butterworth, A; Linnecar, T; Maesen, P; Molendijk, J; Montesinos, E; Valuch, D; Weierud, F

2008-01-01

The installation of the 400 MHz superconducting RF system in LHC is finished and commissioning is under way. The final RF system comprises four cryo-modules each with four cavities in the LHC tunnel straight section round IP4. Also underground in an adjacent cavern shielded from the main tunnel are the sixteen 300 kW klystron RF power sources with their high voltage bunkers, two Faraday cages containing RF feedback and beam control electronics, and racks containing all the slow controls. The system and the experience gained during commissioning will be described. In particular, results from conditioning the cavities and their movable main power couplers and the setting up of the low level RF feedbacks will be presented.

Vacuum system for LHC

International Nuclear Information System (INIS)

Groebner, O.

1995-01-01

The Large Hadron Collider (LHC) which is planned at CERN will be housed in the tunnel of the Large Electron Positron collider (LEP) and will store two counter-rotating proton beams with energies of up to 7 TeV in a 27 km accelerator/storage ring with superconducting magnets. The vacuum system for the LHC will be at cryogenic temperatures (between 1.9 and 20 K) and will be exposed to synchrotron radiation emitted by the protons. A stringent limitation on the vacuum is given by the energy deposition in the superconducting coils of the magnets due to nuclear scattering of the protons on residual gas molecules because this may provoke a quench. This effect imposes an upper limit to a local region of increased gas density (e.g. a leak), while considerations of beam lifetime (100 h) will determine more stringent requirements on the average gas density. The proton beam creates ions from the residual gas which may strike the vacuum chamber with sufficient energy to lead to a pressure 'run-away' when the net ion induced desorption yield exceeds a stable limit. These dynamic pressure effects will be limited to an acceptable level by installing a perforated 'beam screen' which shields the cryopumped gas molecules at 1.9 K from synchrotron radiation and which also absorbs the synchrotron radiation power at a higher and, therefore, thermodynamically more efficient temperature. (author)

Precision-guided vehicle for transport and installation of LHC cryomagnets

CERN Multimedia

Maximilien Brice

2003-01-01

LHC quadrupoles and dipoles are heavier, longer and more fragile than the magnets used in CERN s former LEP collider. Therefore, an innovative solution for their transport and installation in the tunnel has been developed. It consists of convoys of two tractors, a trailer and unloading equipment. The convoys feature infrared optical guidance, which offsets the minimal clearance inside the tunnel, and are designed to minimize vibration of the magnets during transport. Operations will be monitored by a technician, who will take over the controls to unload and install the magnets. The first such convoy is now undergoing testing in the tunnel. The people who have contributed to the new transport system are pictured here at Point 4 in the LHC tunnel where tests on the first convoy are being conducted. The optical guidance system uses the white lines on the floor (Photos 01 and 03) to steer the vehicle in the tunnel. The prototype quadrupole magnet used in the tests is visible in Photos 02 and 04.

LHC Highlights, from dream to reality

CERN Multimedia

CERN Bulletin

2010-01-01

The idea of the Large Hadron Collider (LHC) was born in the early 1980s. Although LEP (CERN’s previous large accelerator) was still under construction at that time, scientists were already starting to think about re-using the 27-kilometre ring for an even more powerful machine. Turning this ambitious scientific plan into reality proved to be an immensely complex task. Civil engineering work, state-of-the-art technologies, a new approach to data storage and analysis: many people worked hard for many years to accomplish all this.   Here are some of the highlights: 1984. A symposium organized in Lausanne, Switzerland, is the official starting point for the LHC. LHC prototype of the two beam pipes (1992). 1989. The first embryonic collaborations begin. 1992. A meeting in Evian, France, marks the beginning of the LHC experiments. 1994. The CERN Council approves the construction of the LHC accelerator. 1995. Japan becomes an Observer of CERN and announces a financial contribution to ...

Design, construction and start up by Air Liquide of two 18 kW at 45 K helium refrigerators for the new CERN accelerator (LHC)

CERN Document Server

Dauguet, P; Delcayre, F; Ghisolfi, A; Gistau-Baguer, Guy M; Guerin, C A; Hilbert, B; Marot, G; Monneret, E

2004-01-01

CERN in Switzerland is presently building a new particle accelerator labeled as the LHC. This 27 km accelerator will, for the first time at such a large scale, operate at cryogenic temperatures with superconducting magnets and radio-frequency cavities. For that purpose, Air Liquide has designed, constructed and started up two custom designed refrigerators. The cryogenic power of each of these refrigerators is equivalent to 18 kW at 4.5 K. In order to produce the cryogenic power requested by the LHC accelerator at the different temperature levels with a very high efficiency, a custom design thermodynamic cycle has been chosen. This cycle, the major components of the refrigerators and the results obtained during the reception tests of the refrigerators are presented in this paper.

Electron cloud buildup studies for the LHC

CERN Document Server

AUTHOR|(CDS)2160803; Boine-Frankenheim, Oliver

Electron clouds can develop in accelerators operating with positively charged particles. The con- sequences of e-cloud related effects are very important for the operation of the Large Hadron Collider (LHC) at CERN, and for the design of future accelerators including the LHC luminosity upgrade (HL-LHC). High electron densities are generated by an interaction between the beam and the confining chamber. Primary electrons, that can be generated through various mecha- nisms, are accelerated by the beam and impinge on the chamber walls, thereby extracting more electrons from the material. Furthermore they also deposit their kinetic energy in the process, which has to be compensated by the cooling system. Especially in cryogenic environments, as it is the case for a large part of the LHC, high heat loads can pose a serious problem. In order to improve the understanding of the electron cloud, simulation studies are performed with the code PyECLOUD, developed at CERN. The work of the first half of the project is desc...

Optical fibres bringing the LHC into focus

CERN Multimedia

2003-01-01

New components are being added to CERN's optical fibre network, which will transport the torrents of data produced by the LHC. 1500 kilometres of cables will be installed in the tunnels and at ground level.

HL-LHC kicker magnet (MKI)

CERN Multimedia

Brice, Maximilien

2018-01-01

HL-LHC kicker magnet (MKI): last vacuum test, preparation for transport to LHC transfer line in underground tunnel.The LHC injection kicker systems (MKIs) generate fast field pulses to inject the clockwise rotating beam at Point 2 and the anti-clockwise rotating beam at Point 8: there are eight MKI magnets installed in total. Each MKI magnet contains a high purity alumina tube: if an MKI magnet is replaced this tube requires conditioning with LHC beam: until it is properly conditioned, there can be high vacuum pressure due to the beam. This high pressure can also cause electrical breakdowns in the MKI magnets. A special coating (Cr2O3) has been applied to the inside of the alumina tube of an upgraded MKI magnet – this is expected to greatly reduce the pressure rise with beam. In addition, HL-LHC beam would result in excessive heating of the MKI magnets: the upgraded design includes modifications that will reduce heating, and move the power deposition to parts that will be easier to cool. Experience during 2...

LHC Report: Preparing for 4 TeV

CERN Multimedia

Edited by Katarina Anthony based on regular reports by Mike Lamont, the Bulletin's correspondent from Chamonix

2012-01-01

After more than two months since its stop in December, the LHC is slowly coming back from its hibernation - even if the temperature of the magnets in the tunnel has actually been getting lower and lower in recent days. The tunnel has been crowded with hundreds of people, busy with maintenance activities and preparations for the restart. The end of most activities (and the access to the tunnel) is scheduled for 21 February. On this date, the Operations team will take back ownership of the machine from the Programmed Stops Coordination team and push forward the preparations for the beam.   The cool-down of all LHC sectors (left floating at around 80 K during the Christmas break) restarted three weeks ago. At present, more than half of the machine is at nominal cryogenic temperature and the completion of the cool-down is expected by 27 February. As soon as a sector is cold, the Electrical Quality Assurance (ElQA) team starts the high-voltage qualification of the superconducting circuits, to check ins...

Machine protection: availability for particle accelerators

International Nuclear Information System (INIS)

Apollonio, A.

2015-01-01

Machine availability is a key indicator for the performance of the next generation of particle accelerators. Availability requirements need to be carefully considered during the design phase to achieve challenging objectives in different fields, as e.g. particle physics and material science. For existing and future High-Power facilities, such as ESS (European Spallation Source) and HL-LHC (High-Luminosity LHC), operation with unprecedented beam power requires highly dependable Machine Protection Systems (MPS) to avoid any damage-induced downtime. Due to the high complexity of accelerator systems, finding the optimal balance between equipment safety and accelerator availability is challenging. The MPS architecture, as well as the choice of electronic components, have a large influence on the achievable level of availability. In this thesis novel methods to address the availability of accelerators and their protection systems are presented. Examples of studies related to dependable MPS architectures are given in the thesis, both for Linear accelerators (Linac4, ESS) and circular particle colliders (LHC and HL-LHC). A study of suitable architectures for interlock systems of future availability-critical facilities is presented. Different methods have been applied to assess the anticipated levels of accelerator availability. The thesis presents the prediction of the performance (integrated luminosity for a particle collider) of LHC and future LHC up- grades, based on a Monte Carlo model that allows reproducing a realistic timeline of LHC operation. This model does not only account for the contribution of MPS, but extends to all systems relevant for LHC operation. Results are extrapolated to LHC run 2, run 3 and HL-LHC to derive individual system requirements, based on the target integrated luminosity. (author)

CERN reacts to increased costs to completion of the LHC

CERN Multimedia

2002-01-01

Aspects of LHC construction. The CERN Council, where the representatives of the 20 Member States of the Organization decide on scientific programmes and financial resources, held its 120th session on 14 December under the chairmanship of Prof. Maurice Bourquin (CH). CERN adjusts to the LHC Director-General, Luciano Maiani, stressed that CERN was now fully engaged in the LHC and outlined the first moves to react to the increased cost to completion of the LHC. The new accelerator is an extremely complex, high-tech project which CERN is building under very severe conditions. However, the technical challenges are solved and industrial production of accelerator elements, and installation are starting. Professor Maiani said that 2001 had been a very hard but decisive year for CERN. An important milestone had been passed during this meeting with the approval of the LHC dipole magnets contract, the last major contract for the accelerator. The new costs to completion of the LHC project are now clear. A first propos...

The LHC Project Status and Prospects

CERN Document Server

Faugeras, Paul E

2001-01-01

The Large Hadron Collider (LHC), CERN's future major facility for high-energy physics, has entered into the construction and preparation for installation phases. After recalling briefly the main machine design choices and challenges, one will review the progress of civil works for the machine and experimental areas and the status of the main LHC components, which are presently series-built and for some of them procured in kind through world-wide collaborations. Report will also be given on the full-scale prototype of an elementary LHC lattice cell, called String 2, which is being commissioned and used for optimising the installation and testing procedures of the LHC. The size and duration of the LHC Project, its intrinsic complexity and the large number of world-wide collaborations involved require rather elaborate project management tools, which will be shortly described. Finally, following the extended running of the LEP and the delay for emptying of the machine tunnel, a new planning for project completion...

LHC INAUGURATION, LHC Fest highlights: exhibition time!

CERN Multimedia

2008-01-01

David Gross, one of the twenty-one Nobel Laureates who have participated in the project.Tuesday 21 October 2008 Accelerating Nobels Colliding Charm, Atomic Cuisine, The Good Anomaly, A Quark Somewhere on the White Paper, Wire Proliferation, A Tale of Two Liquids … these are just some of the titles given to artworks by Physics Nobel Laureates who agreed to make drawings of their prize-winning discoveries (more or less reluctantly) during a special photo session. Science photographer Volker Steger made portraits of Physics Nobel Laureates and before the photo sessions he asked them to make a drawing of their most important discovery. The result is "Accelerating Nobels", an exhibition that combines unusual portraits of and original drawings by twenty-one Nobel laureates in physics whose work is closely related to CERN and the LHC. This exhibition will be one of the highlights of the LHC celebrations on 21 October in the SM18 hall b...

Suitability of tunneling ionization produced plasmas for the plasma beat wave accelerator

International Nuclear Information System (INIS)

Leeman, W.P.; Clayton, C.E.; Marsh, K.A.; Dyson, A.; Joshi, C.

1991-01-01

Tunneling ionization can be thought of as the high intensity, low frequency limit of multi-photon ionization (MPI). Extremely uniform plasmas were produced by the latter process at Rutherford lab for beat wave excitation experiments using a 0.5 μm laser. Plasmas with 100% ionization were produced with densities exceeding 10 17 cm -3 . The experiment uses a CO 2 laser (I max ∼ 5 x 10 14 W/cm 2 ) which allows the formation of plasmas via the tunneling process. For the experiments the authors need plasmas with densities in the range of 5 to 10 x 10 16 cm -3 . Using Thomson scattering as a diagnostic they have explored the density and temperature regime of tunneling ionization produced plasmas. They find that plasmas with densities up to 10 16 cm -3 can indeed be produced and that these plasmas are hot. Beyond this density strong refraction of laser radiation occurs due to the radial profile of the plasma. Implications of this work to the Beat Wave Accelerator program will be discussed

LHC: forwards and onwards

CERN Multimedia

2008-01-01

Following the recent incident in Sector 3-4, which has brought the start-up of the LHC to a halt, the various teams are working hard to establish the cause, evaluate the situation and plan the necessary repairs. The LHC will be started up again in spring 2009 following the winter shutdown for the maintenance of all the CERN installations. The LHC teams are at work on warming up Sector 3-4 and establishing the cause of the serious incident that occurred on Friday, 19 September. Preliminary investigations suggest that the likely cause of the problem was a faulty electrical connection between two magnets. The connections probably melted, leading to a mechanical failure and a large leak of helium into the tunnel. However, the teams will not be able to carry out a full evaluation and assess the repairs needed until the sector has been warmed up again and inspected. "We are not worried about repairing the magnets as spare parts are available", said Lyn Evans, the LHC Project Leade...

LIGHT and LUMINOSITY, from Einstein to LHC

CERN Multimedia

CERN. Geneva; Prof. ROSSI, Lucio

2015-01-01

After an introduction on the concept of light in physics, this talk will focus on CERN’s High Luminosity LHC project, aiming at extending the discovery potential of CERN’s flagship accelerator by increasing its “luminosity” (ie the number of particles that can be squeezed inside the accelerator to maximize the number of collisions). To achieve this objective, many new technologies are being developed at CERN and many collaborating institutes worldwide, especially in the field of superconductivity. Lucio Rossi, the main speaker, is the head of the HL-LHC project, based at CERN. Giorgio Apollinari, Director for the LHC Accelerator Research Program (LARP) will speak through a videoconference from Fermilab (USA). The event is webcast live and will be followed by Fermilab and other institutes in the USA.

LHC Report: a record start for LHC ion operation

CERN Multimedia

Jan Uythoven for the LHC Team

2011-01-01

After the technical stop, the LHC switched over to ion operation, colliding lead-ions on lead-ions. The recovery from the technical stop was very smooth, and records for ion luminosity were set during the first days of ion operation.   The LHC technical stop ended on the evening of Friday, 11 November. The recovery from the technical stop was extremely smooth, and already that same evening ion beams were circulating in the LHC. ‘Stable beams’ were declared the same night, with 2 x 2 bunches of ions circulating in the LHC, allowing the experiments to have their first look at ion collisions this year. However, the next step-up in intensity – colliding 170 x 170 bunches – was postponed due to a vacuum problem in the PS accelerator, so the collisions on Sunday, 13 November were confined to 9 x 9 bunches. The vacuum problem was solved, and on the night of Monday, 14 November, trains of 24 lead bunches were injected into the LHC and 170 x 170 bunches were brough...

Risk analysis of the LHC underground area fire risk due to faulty electrical equipment

CERN Document Server

Harrison, A

2007-01-01

The European Organisation for Nuclear Research (CERN) in Geneva, Switzerland, is currently building the latest generation of particle accelerators, the LHC (Large Hadron Collider). The machine is housed in a circular tunnel of 27 km of circumference and is situated approximately 100 metres beneath the surface astride the Franco-Swiss border. Electrically induced fires in the LHC are a major concern, since an incident could present a threat to CERN personnel as well as the public. Moreover, the loss of equipment would result in significant costs and downtime. However, the amount of electrical equipment in the underground area required for operation, supervision and control of the machine is essential. Thus the present thesis is assessing the risk of fire due to faulty electrical equipment in both a qualitative as well as quantitative way. The recommendations following the qualitative analysis suggest the introduction of fire protection zones for the areas with the highest risk of fire due to a combination of p...

The LHC dipole test control architecture

International Nuclear Information System (INIS)

Gorskaya, E.; Samojlov, V.; Raimondo, A.; Rijllart, A.

2003-01-01

The next large accelerator project at CERN is the Large Hadron Collider, which is foreseen to be installed in the existing LEP tunnel, and scheduled to be commissioned in 2007. For this project, 1200 15-metre long dipole magnets need to be tested at CERN in warm and cold conditions on dedicated test benches that are under development. The final LHC dipole series test set-up will consist of 12 benches organized in 6 clusters of two benches sharing the largest and most expensive devices. This sharing is made possible by a deliberate de-phasing of the tests among magnets, ensuring an optimum use of resources, such as cryogenics and power equipment, without limiting the total throughput. An offered two-level control architecture includes: 1) the Test 'Master' that drives the test for a cluster; 2) the Resource 'Manager' that allocates common devices and central resources. The implementation of this architecture is done in the LabVIEW environment

New magnet transport system for the LHC beam transfer lines

CERN Multimedia

Patrice Loïez

2003-01-01

The first of 700 magnets has been installed in one of the two transfer tunnels built to transfer the SPS beam into the LHC. The start of this first installation phase of the LHC transfer lines provides the opportunity to launch a new and highly original modular system for transporting and installing all kinds of magnets in very narrow tunnels. The system (pictured here in one of the tunnels) is based on very compact bogies, up to four of which can be coupled together to form a convoy. The wheels are fitted with individual motors enabling them to swivel through an angle of 90° and the convoy to move laterally. The lead vehicle is powered by an electric rail set into the roof of the tunnel. The system is backed up by electrical batteries that enable it to operate in the absence of an outside power source or in the event of power failure. Last but not least, for the long-distance transport of magnets, it can be optically guided by a line traced on the tunnel floor. The convoy moves through the particularly narr...

High Luminosity LHC: challenges and plans

Science.gov (United States)

Arduini, G.; Barranco, J.; Bertarelli, A.; Biancacci, N.; Bruce, R.; Brüning, O.; Buffat, X.; Cai, Y.; Carver, L. R.; Fartoukh, S.; Giovannozzi, M.; Iadarola, G.; Li, K.; Lechner, A.; Medina Medrano, L.; Métral, E.; Nosochkov, Y.; Papaphilippou, Y.; Pellegrini, D.; Pieloni, T.; Qiang, J.; Redaelli, S.; Romano, A.; Rossi, L.; Rumolo, G.; Salvant, B.; Schenk, M.; Tambasco, C.; Tomás, R.; Valishev, S.; Van der Veken, F. F.

2016-12-01

The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up a new energy frontier for exploration in 2010, it has gathered a global user community working in fundamental particle physics and the physics of hadronic matter at extreme temperature and density. To sustain and extend its discovery potential, the LHC will undergo a major upgrade in the 2020s. This will increase its rate of collisions by a factor of five beyond the original design value and the integrated luminosity by a factor ten. The new configuration, known as High Luminosity LHC (HL-LHC), will rely on a number of key innovations that push accelerator technology beyond its present limits. Among these are cutting-edge 11-12 T superconducting magnets, including Nb3Sn-based magnets never used in accelerators before, compact superconducting cavities for longitudinal beam rotation, new technology and physical processes for beam collimation. The dynamics of the HL-LHC beams will be also particularly challenging and this aspect is the main focus of this paper.

High Luminosity LHC: Challenges and plans

International Nuclear Information System (INIS)

Arduini, G.; Barranco, J.; Bertarelli, A.; Biancacci, N.; Bruce, R.

2016-01-01

The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up a new energy frontier for exploration in 2010, it has gathered a global user community working in fundamental particle physics and the physics of hadronic matter at extreme temperature and density. To sustain and extend its discovery potential, the LHC will undergo a major upgrade in the 2020s. This will increase its rate of collisions by a factor of five beyond the original design value and the integrated luminosity by a factor ten. The new configuration, known as High Luminosity LHC (HL-LHC), will rely on a number of key innovations that push accelerator technology beyond its present limits. Among these are cutting-edge 11–12 T superconducting magnets, including Nb 3 Sn-based magnets never used in accelerators before, compact superconducting cavities for longitudinal beam rotation, new technology and physical processes for beam collimation. As a result, the dynamics of the HL-LHC beams will be also particularly challenging and this aspect is the main focus of this paper.

Press Conference: LHC Restart, Season 2

CERN Multimedia

CERN. Geneva

2015-01-01

PRESS BRIEFING ON THE LARGE HADRON COLLIDER (LHC) RE-START, SEASON 2 AT CERN, GLOBE OF SCIENCE AND INNOVATION Where :   http://cern.ch/directions   at the Globe of Science and Innovation When : Thursday, 12 March from 2.30 to 3.30pm - Open seating as from 2.15pm Speakers : CERN’s Director General, Rolf Heuer and Director of Accelerators, Frédérick Bordry, and representatives of the LHC experiments Webcast : https://webcast.web.cern.ch/webcast/ Dear Journalists, CERN is pleased to invite you to the above press briefing which will take place on Thursday 12 March, in the Globe of Science and Innovation, 1st floor, from 2.30 to 3.30pm. The Large Hadron Collider (LHC) is ready to start up for its second three-year run. The 27km LHC is the largest and most powerful particle accelerator in the world operating at a temperature of -217 degrees Centigrade and powered to a current of 11,000 amps. Run 2 of the LHC follows a two-year technical s...

The LHC detectors and the first CMS data

CERN Document Server

Green, Dan

2015-01-01

This chapter describes the subsystems of a generic LHC detector and explains how the values of the detector parameters were selected. The design of the LHC detectors follows from the requirement of confronting electroweak symmetry breaking in a decisive fashion. The LHC accelerator also meets those requirements.

Study for magnets and electronics protection in the LHC Betatron-cleaning insertion

International Nuclear Information System (INIS)

Magistris, Matteo; Ferrari, Alfredo; Santana, Mario; Tsoulou, Katerina; Vlachoudis, Vasilis

2006-01-01

The collimation system of the future LHC at CERN is a challenging project, since the transverse energy intensities of the LHC beams are three orders of magnitude greater than at other current facilities. The two cleaning insertions (IR3 and IR7) housing the collimators will be among the most radioactive areas of LHC. The 1.5 km long IR7 insertion was fully implemented with the Monte Carlo cascade code FLUKA. Extensive simulations were performed to estimate the radiation level along the tunnel, as well as the energy deposition in the most critical elements. In particular, this paper discusses the latest results of the FLUKA studies, including the design of passive absorbers (to protect warm magnets) and a comparison of W and Cu as material for the active absorber jaws (to protect cold magnets). Any electronic device operating in strong radiation fields such as those expected for the LHC tunnel will undergo degradation. A shielding study was done to reduce radiation damage to the electronics

Big advance towards the LHC upgrade

CERN Multimedia

CERN Bulletin

2010-01-01

The LHC is currently the world’s most powerful accelerator. With its technical achievements it has already set world records. However, big science looks very far ahead in time and is already preparing already for the LHC’s magnet upgrade, which should involve a 10-fold increase of the collision rates toward the end of the next decade. The new magnet technology involves the use of an advanced superconducting material that has just started to show its potential.   The first Long Quadrupole Shell (LQS01) model during assembly at Fermilab. The first important step in the qualification of the new technology for use in the LHC was achieved at the beginning of December when the US LHC Accelerator Research Program (LARP) – a consortium of Brookhaven National Laboratory, Fermilab, Lawrence Berkeley National Laboratory and the SLAC National Accelerator Laboratory founded by US Department Of Energy (DOE) in 2003 – successfully tested the first long focussing magnet th...

The High-Luminosity upgrade of the LHC: Physics and Technology Challenges for the Accelerator and the Experiments

Science.gov (United States)

Schmidt, Burkhard

2016-04-01

In the second phase of the LHC physics program, the accelerator will provide an additional integrated luminosity of about 2500/fb over 10 years of operation to the general purpose detectors ATLAS and CMS. This will substantially enlarge the mass reach in the search for new particles and will also greatly extend the potential to study the properties of the Higgs boson discovered at the LHC in 2012. In order to meet the experimental challenges of unprecedented pp luminosity, the experiments will need to address the aging of the present detectors and to improve the ability to isolate and precisely measure the products of the most interesting collisions. The lectures gave an overview of the physics motivation and described the conceptual designs and the expected performance of the upgrades of the four major experiments, ALICE, ATLAS, CMS and LHCb, along with the plans to develop the appropriate experimental techniques and a brief overview of the accelerator upgrade. Only some key points of the upgrade program of the four major experiments are discussed in this report; more information can be found in the references given at the end.

CERN Open Days 2013, Point 6: Accelerator Systems

CERN Multimedia

CERN Photolab

2013-01-01

Stand description: Each beam of protons that races around the Large Hadron Collider can contain as much energy as a French TGV train travelling at 150 km/hour.  When it's time to shut the machine down, the Beam Dump System ensures that this energy is safely dissipated. In the tunnel at Point 6 you will be able to see the devices which form part of this system, as well as the blue LHC dipole magnets curving away into the distance. On surface no restricted access  On the surface, you can explore a fascinating exhibition of equipment used in CERN's accelerators, with CERN engineers and physicists on hand all day to answer your questions. You will also see one of the cryogenics installations which keep the LHC at just few degrees above absolute zero and you can find out about the measures CERN has put in place to ensure safety and protect the environment.

Low energy accelerators for research and applications

International Nuclear Information System (INIS)

Bhandari, R.K.

2013-01-01

Charged particle accelerators are instruments for producing a variety of radiations under controlled conditions for basic and applied research as well as applications. They have helped enormously to study the matter, atoms, nuclei, sub-nuclear particles and their constituents, forces involved in the related phenomena etc. No other man-made instrument has been so effective in such studies as the accelerator. The large accelerator constructed so far is the Large Hadron Collider (LHC) housed in a tunnel of 27 km circumference, while a small accelerator can fit inside a room. Small accelerators accelerate charged particles such as electrons, protons, deuterons, alphas and, in general ions to low energy, generally, below several MeV. These particle beams are used for studies in nuclear astrophysics, atomic physics, material science, surface physics, bio sciences etc. They are used for ion beam analysis such as RBS, PIXE, NRA, AMS, CPAA etc. More importantly, the ion beams have important industrial applications like ion implantation, surface modification, isotope production etc. while electron beams are used for material processing, material modification, sterilization, food preservation, non destructive testing etc. In this talk, role of low energy accelerators in research and industry as well as medicine will be discussed. (author)

1st February 2011-CERN Cultural Board for Engaging with the Arts, visiting CMS experimental area and LHC Tunnel at Point 5

CERN Multimedia

Michael Hoch

2011-01-01

Photo 1-4: Visit to CMS Control Room with G. Tonelli,CMS Collaboration Spokesperson Photo 5-9,16-20:CMS experimental area Photo 10-15:LHC Tunnel at Point 5 Photo 21:F. Madlener,Director of IRCAM Paris+S. Dorny,Director-General Lyon Opera House+C. Bollman,Art by Genève+M. Doser,AEgIS Collaboration Spokesperson,Former Physics Department Deputy Head+A. Koek,International Arts Development+G. Tonelli+M. Monje Cano,Arts Development Assistant (part-time work experience)+B. Ruf,Director of Kunsthalle Zürich

Mechanical Behaviour of the LHC Cryodipoles

CERN Document Server

Buenaventura, A; Skoczen, Blazej

2000-01-01

The LHC cryodipoles are slender and heavy objects more than 15-m long. The major components of the cryodipole assembly are the 28-tonne cold mass, supported on its three Glass-Fibre-Reinforced-Epoxy support posts and the 4-tonne vacuum vessel. The performance of the LHC depends very much upon the accurate positioning of the dipoles and the beam tubes, in particular to maximise the useful beam apertures. The cryodipoles will be conditioned and measured in surface assembly buildings, then handled and transported to their positions in the tunnel and, finally, aligned. This paper presents the static and dynamic studies of the cryodipole in different configurations. The tests and analyses carried out have led to a thorough understanding of the mechanical behaviour of the cryodipoles. From the static analysis, an hyperstatic supporting system is proposed in order to minimise the systematic deflections and the effects due to changing temperature conditions in the tunnel. The dynamic analysis has shown that the cryod...

First Assessment of Reliability Data for the LHC Accelerator and Detector Cryogenic System Components

CERN Document Server

Perinic, G; Alonso-Canella, I; Balle, C; Barth, K; Bel, J F; Benda, V; Bremer, J; Brodzinski, K; Casas-Cubillos, J; Cuccuru, G; Cugnet, M; Delikaris, D; Delruelle, N; Dufay-Chanat, L; Fabre, C; Ferlin, G; Fluder, C; Gavard, E; Girardot, R; Haug, F; Herblin, L; Junker, S; Klabi , T; Knoops, S; Lamboy, J P; Legrand, D; Metselaar, J; Park, A; Perin, A; Pezzetti, M; Penacoba-Fernandez, G; Pirotte, O; Rogez, E; Suraci, A; Stewart, L; Tavian, L J; Tovar-Gonzalez, A; Van Weelderen, R; Vauthier, N; Vullierme, B; Wagner, U

2012-01-01

The Large Hadron Collider (LHC) cryogenic system comprises eight independent refrigeration and distribution systems that supply the eight 3.3 km long accelerator sectors with cryogenic refrigeration power as well as four refrigeration systems for the needs of the detectors ATLAS and CMS. In order to ensure the highest possible reliability of the installations, it is important to apply a reliability centred approach for the maintenance. Even though large scale cryogenic refrigeration exists since the mid 20th century, very little third party reliability data is available today. CERN has started to collect data with its computer aided maintenance management system (CAMMS) in 2009, when the accelerator has gone into normal operation. This paper presents the reliability observations from the operation and the maintenance side, as well as statistical data collected by the means of the CAMMS system.

Digging in one last time for the LHC

CERN Multimedia

2003-01-01

A landmark event occurred during the second week of March, when the final cubic metres of earth were cleared away, completing the excavation phase for the entire LHC project . The event took place at Point 5, where the CMS detector will be installed, as civil engineering teams finished digging the cavern that connects the LHC tunnel with the bypass tunnel around the experimental cavern. Two new access shafts, two large caverns, two ancillary caverns, as well as the connecting tunnels have been excavated by the civil engineering teams. "The engineers heaved a huge sigh of relief when the work was done, because the excavations were quite risky. Anything can happen, and the risk of delays was far from zero," explains Jean Luc Baldy Head of ST Division's civil engineering group. This was especially true around Point 5, where unusual geology created some problems. The moraine-molasse interface lies 50 metres beneath the surface, or just about 18 metres above the roof of the caverns. Because the moraine consists of...

High-precision performance testing of the LHC power converters

CERN Document Server

Bastos, M; Dreesen, P; Fernqvist, G; Fournier, O; Hudson, G

2007-01-01

The magnet power converters for LHC were procured in three parts, power part, current transducers and control electronics, to enable a maximum of industrial participation in the manufacturing and still guarantee the very high precision (a few parts in 10-6) required by LHC. One consequence of this approach was several stages of system tests: factory reception tests, CERN reception tests, integration tests , short-circuit tests and commissioning on the final load in the LHC tunnel. The majority of the power converters for LHC have now been delivered, integrated into complete converter and high-precision performance testing is well advanced. This paper presents the techniques used for high-precision testing and the results obtained.

4-13 kA DC current transducers enabling accurate in-situ calibration for a new particle accelerator project, LHC

CERN Document Server

Hudson, G

2005-01-01

CERN's next generation particle accelerator, the large hadron collider (LHC) requires accurate current measurement up to 13 kA to enable current tracking between individual power converters. DC current transducers (DCCTs) have been developed to allow in-situ calibrations to 10/sup -6/ uncertainty. This paper describes the principle, design and initial evaluations.

Characterization and performance optimization of radiation monitoring sensors for high energy physics experiments at the CERN LHC and Super-LHC

CERN Document Server

Mekki, Julien

2009-01-01

In order to study the matter originating from the universe, a new particle accelerator named the Large Hadron Collider (LHC) has been built at CERN. The radiation environment generated by the hadrons collisions in the high energy physics experiments of the LHC will be complex and locally very intense. For monitoring this complex radiation field, dosimeters have been installed in the LHC experiments. In previous study, RadFET dosimeters and PIN diodes have been characterized for their use in the particle accelerator. However, even if the RadFETs sensors have been already extensively characterized, their radiation response can be affected by their package. Depending on the material and the geometry, the package can induce errors in the dose measurement. In this thesis, a complete study has been carried out in order to evaluate its influence. Concerning the PIN diodes, the readout protocol used for the LHC is no longer valuable for the Super-LHC. Therefore, a complete study on their radiation response has been p...

The metrology of the LHC project: what news?

International Nuclear Information System (INIS)

Chambardon, M.; Missiaen, D.; Quesnel, J.P.; Scandale, W.; Naegely, A.V.; Naegely, P.

1999-01-01

The Large Hadron Collider (LHC), under construction at CERN, uses superconducting magnets operating at a temperature of 1.9 K to guide the circulating particles. A specific feature of the main magnets (dipoles and quadrupoles) is the two-in-one design with two magnetic channels in one common retaining structure. Indeed, the accelerator is made of two rings, mechanically linked, that have to be simultaneously aligned during the installation in the already existing LEP tunnel. The assembly tolerances of the LHC main magnets have been reconsidered to take into account the tight constraints on geometry. The dipoles are bent to follow closely the curvature of the circulating particles and to make a larger mechanical aperture available for the circulating particles. In order to minimise the geometrical errors the dipole assembly procedure is assisted by high precision survey measurements based on laser trackers. By this we hope to reduce to ± 1 mm the positioning error along the axis of the magnets. In addition the ends of the dipoles and quadrupoles should be aligned with even better precision to reduce to below ± 0.3 mm the displacement of the bellows in the magnet-to-magnet interconnection. All these precautions are expected to make easier the installation and to improve the LHC machine operation. In Section 2, we discuss the survey activity related to the civil engineering work. In section 3 we discuss the alignment of the dipoles in their cryostats. In Section 4 we present our geodetic network and in Section 5 we draw our conclusions. (authors)

The LHC magnet system and its status of development

Science.gov (United States)

Bona, Maurizio; Perin, Romeo; Vlogaert, Jos

1995-01-01

CERN is preparing for the construction of a new high energy accelerator/collider, the Large Hadron Collider (LHC). This new facility will mainly consist of two superconducting magnetic beam channels, 27 km long, to be installed in the existing LEP tunnel. The magnetic system comprises about 1200 twin-aperture dipoles, 13.145 m long, with an operational field of 8.65 T, about 600 quadrupoles, 3 m long, and a very large number of other superconducting magnetic components. A general description of the system is given together with the main features of the design of the regular lattice magnets. The paper also describes the present state of the magnet R & D program. Results from short model work, as well as from full scale prototypes will be presented, including the recently tested 10 m long full-scale prototype dipole manufactured in industry.

3 May 2014 - His Excellency Dr Karolos Papoulias President of the Hellenic Republic in the LHC tunnel at Point 1 and in ATLAS experimental cavern with Director-General R. Heuer.

CERN Multimedia

Brice, Maximilien

2014-01-01

In the LHC tunnel at Point 1: Beams Department, Controls Group Leader E. Hatziangeli and Technology Department, Cryogenics Group Deputy Leader D. Delikaris. In the ATLAS cavern: ATLAS Deputy Spokesperson B. Heinemann and ATLAS Collaboration National contact person and CAST Collaboration National Technical University of Athens Team Leader E. Gazis.

27 September 2013 -Lithuanian Minister of Culture Š. Birutis in the LHC tunnel with International Relations Adviser T. Kurtyka and visiting CMS experimental area with Deputy Spokesperson T. Camporesi. Also present: V. Rapsevicius, CMS Collaboration.

CERN Multimedia

Laurent Egli

2013-01-01

27 September 2013 -Lithuanian Minister of Culture Š. Birutis in the LHC tunnel with International Relations Adviser T. Kurtyka and visiting CMS experimental area with Deputy Spokesperson T. Camporesi. Also present: V. Rapsevicius, CMS Collaboration.

20 January 2014 - Members of the Regional Assemblies and Parliaments United Kingdom of Great Britain and Northern Ireland visiting the LHC tunnel at Point 8 with Technology Department, Vacuum, Surfaces and Coatings Group P. Cruikshank.

CERN Document Server

Pantelia, Anna

2014-01-01

20 January 2014 - Members of the Regional Assemblies and Parliaments United Kingdom of Great Britain and Northern Ireland visiting the LHC tunnel at Point 8 with Technology Department, Vacuum, Surfaces and Coatings Group P. Cruikshank.

4 April 2013 - Spanish State Secretary of Science, Development and Innovation C. Vela Olmo in the LHC tunnel with Technology Department Head F. Bordry and signing the guest book with CERN Director-General R. Heuer.

CERN Multimedia

Anna Pantelia

2013-01-01

4 April 2013 - Spanish State Secretary of Science, Development and Innovation C. Vela Olmo in the LHC tunnel with Technology Department Head F. Bordry and signing the guest book with CERN Director-General R. Heuer.

The Radiation Tolerant Electronics for the LHC Cryogenic Controls: Basic Design and First Operational Experience

CERN Document Server

Casas-Cubillos, J; Rodríguez-Ruiz, M A

2008-01-01

The LHC optics is based in the extensive use of superconducting magnets covering 23 km inside the tunnel. The associated cryogenic system for keeping the magnets in nominal conditions is hence distributed all around the 27 km LHC tunnel and the cryogenic instrumentation submitted to the LHC radiation environment is composed of about 18’000 sensors and actuators. Radiation Tolerant (RadTol) electronics was designed and procured in order to keep the signals integrity against electromagnetic interference and to reduce cabling costs required in case of sending the analog signals into the 30 radiation protected areas. This paper presents the basic design, the qualification of the main RadTol components and the first operational results.

Design of a 0-50 mbar pressure measurement channel compatible with the LHC tunnel radiation environment

Science.gov (United States)

Casas, Juan; Jelen, Dorota; Trikoupis, Nikolaos

2017-02-01

The monitoring of cryogenic facilities often require the measurement of pressure in the sub 5’000 Pa range that are used for flow metering applications, for saturated superfluid helium, etc. The pressure measurement is based on the minute displacement of a sensing diaphragm often through contactless techniques by using capacitive or inductive methods. The LHC radiation environment forbid the use of standard commercial sensors because of the embedded electronics that are affected both by radiation induced drift and transient Single Event Effects (SEE). Passive pressure sensors from two manufacturers were investigated and a CERN designed radiation-tolerant electronics has been developed for measuring variable-reluctance sensors. During the last maintenance stop of the LHC accelerator, four absolute pressure sensors were installed in some of the low pressure bayonet heat exchangers and four differential pressure sensors on the venturi flowmeters that monitor the cooling flow of the 20.5 kA current leads of the ATLAS end-cap superconducting toroids. The pressure sensors operating range is about 1000 to 5000 Pa and the targeted uncertainty is +/- 50 Pa which would permit to measure the equivalent saturation temperature at 1.8 K within better than 0.01 K. This paper describes the radiation hard measuring head that is based on an inductive bridge, its associated radiation-tolerant electronics that is installed under the LHC superconducting magnets or the ATLAS detector cavern; and the first operational experience.

LHC Cryogenics on the mend

CERN Multimedia

2004-01-01

On 29 September, repairs began on the LHC cryogenic distribution line, or QRL, to replace a faulty part that occurs in the hundreds of elements of the line that are already on-site. The Accelerator Technology Department is designing a work programme to finish the repairs as soon as possible and minimize delays to the rest of the LHC project.

A large scale flexible real-time communications topology for the LHC accelerator

CERN Document Server

Lauckner, R J; Ribeiro, P; Wijnands, Thijs

1999-01-01

The LHC design parameters impose very stringent beam control requirements in order to reach the nominal performance. Prompted by the lack of accurate models to predict field behaviour in superconducting magnet systems the control system of the accelerator will provide flexible feedback channels between monitors and magnets around the 27 Km circumference machine. The implementation of feedback systems composed of a large number of sparsely located elements presents some interesting challenges. Our goal was to find a topology where the control loop requirements: number and distribution of nodes, latency and throughput could be guaranteed without compromising the flexibility. Our proposal is to federate a number of well known technologies and concepts, namely ATM, WorldFIP and RTOS, into a general framework. (6 refs).

Real-Time Schottky Measurements in the LHC

CERN Document Server

AUTHOR|(CDS)2241943; Aune, D.

The accelerator complex at the European Organization for Nuclear Research (CERN) is a diverse collection of machines, tailored for different energy ranges, and concatenated in order to accelerate/decelerate particle beams. Leading up to CERN’s flagship accelerator, the Large Hadron Collider (LHC), every accelerator in the chain boosts the particles to higher energies before they are injected into the next machine in the sequence. The LHC is a circular synchrotron accelerator consisting of two 27-kilometer vacuum tubes equipped with superconducting magnets and accelerating RF cavities in order to increase the energy of the particles along the way. Inside the vacuum tubes, two counter-rotating high-energy particle beams travel at velocities close to the speed of light before they are made to collide inside particle detectors at a centre-of-mass energy of 13 TeV. As the particles are accelerated, they experience various external and internal forces. RF cavities are used to boost the speed of the particles an...

LHC Report: focus on luminosity

CERN Document Server

Reyes Alemany Fernandez for the LHC team

2016-01-01

The intensity ramp-up of the LHC beams resumed last Friday after the main powering system of the PS accelerator was put back in service.    The image above shows the last twenty four hours of fill #4947 in the machine. The LHC operations team kept the beams of this fill in the machine for a record 35 and a half hours.  Beams are back in the LHC. On Friday, the accelerator resumed the intensity ramp-up, reaching 1752 bunches per beam last week-end. The intensity ramp-up was interrupted on 20 May because of a problem with the PS’s main power supply (see box). A steady increase in the total number of bunches per beam is required to check out all aspects of beam operation and make sure the LHC is fully safe before the nominal number of bunches per beam can be brought into collision. At present, four intensity steps have been completed: 313, 601, 889, and 1177 bunches per beam. The qualification of the next step with 1752 bunches is in progress. At every s...

An improved scattering routine for collimation tracking studies at LHC

CERN Document Server

Tambasco, Claudia; Salvachua Ferrando, Maria Belen; Cavoto, Gianluca

The present Master thesis work has been carried out at CERN in the framework of the LHC (Large Hadron Collider) Collimation project. The LHC accelerates proton beams up to 7 TeV colliding in the experiment detectors installed in four points of the accelerator ring. The LHC is built to store a energy of 360MJ for each beam. The energy deposition induced by local beam losses could quench the superconducting magnets located around the accelerator beam pipes. To prevent and keep under control dangerous beam losses, an efficient collimation system is required. In addition, the achievable LHC beam intensity is related to the beam loss rate and, consequently, to the cleaning efficiency of the collimation system. Collimation studies at LHC are carried out also by means of simulations by using SixTrack, a dedicated simulation tool that tracks a large numbers of particles for many turns around the ring. The SixTrack code includes a scattering routine to model proton interactions with the material of the collimators j...

Installation of the LHC transfer lines begins

CERN Multimedia

Patrice Loïez

2003-01-01

The first of 700 magnets has been installed in one of the two transfer tunnels built to transfer the SPS beam into the LHC. The start of this first installation phase of the LHC transfer lines provides the opportunity to launch a new and highly original modular system for transporting and installing all kinds of magnets in very narrow tunnels. The system is based on very compact bogies, up to four of which can be coupled together to form a convoy. The wheels are fitted with individual motors enabling them to swivel through an angle of 90° and the convoy to move laterally. In this way the magnet is delivered directly to its installation point, but beneath the beamline. It is then raised into its final position in the beamline using air cushions, which form an integrated part of the transport system. Here we see the transport vehicle alongside the magnet supports. Visible in the background is the first magnet in place.

QCD-instantons at LHC. Theoretical aspects; QCD-Instantonen am LHC. Theoretische Aspekte

Energy Technology Data Exchange (ETDEWEB)

Petermann, M.

2007-06-15

Instantons are nonperturbative, topologically nontrivial field configurations, which occur in every nonabelian gauge theory. They can be understood as tunneling processes between topologically distinct vacua. Although being a basic theoretical aspect of the Standard Model, a direct experimental verification of instanton processes is still lacking. In this thesis the general discovery potential for QCD-instantons at the LHC is studied in detail by means of instanton perturbation theory. In this context the close correspondence between the leading instanton induced processes at HERA and at LHC becomes important. Essential aspects and differences to deep inelastic scattering can already be revealed by studying the simplest process. Based on these results inclusive cross sections are calculated including the emission of final state gluons. Compared to deep inelastic scattering, a large enhancement of the cross section is found. (orig.)

Open Access to the LHC takes on a new meaning

CERN Multimedia

2008-01-01

Complete scientific documentation on the LHC machine and detectors is now freely available on the Web. The ATLAS collaboration, shown here, contributed to the 1,600-page scientific documentation of the LHC, along with staff from the other five detectors and the LHC machine.Now that the LHC tunnel and the experimental caverns are shut down for public visits, "Open Access to the LHC" has taken on an entirely new meaning. Last Thursday, 14 August, seven major articles were published electronically in a special issue of the Journal of Instrumentation (JINST). Together they form the complete scientific documentation on the design and construction of the LHC machine and the six detectors (ALICE, ATLAS, CMS, LHCb, LHCf and TOTEM), and thus on the entire LHC project, well before start-up on 10 September. For many years to come, these papers will serve as key references for the stream of scientific results that will begin to emerge from the ...

Dipoles for High-Energy LHC

CERN Document Server

Todesco, E; De Rijk, G; Rossi, L

2014-01-01

For the High Energy LHC, a study of a 33 TeV center of mass collider in the LHC tunnel, main dipoles of 20 T operational field are needed. In this paper we first review the conceptual design based on block coil proposed in the Malta workshop, addressing the issues related to coil fabrication and assembly. We then propose successive simplifications of this design, associating a cost estimate of the conductor. We then analyse a block layout for a 15 T magnet. Finally, we consider two layouts based on the D20 and HD2 short models built by LBL. A first analysis of the aspects related to protection of these challenging magnets is given.

Radiation environment in the tunnel of a high-energy proton accelerator at energies near 1 TeV

International Nuclear Information System (INIS)

McCaslin, J.B.; Sun, R.K.S.; Swanson, W.P.

1987-12-01

Neutron energy spectra, fluence distributions and rates in the FNAL Tevatron tunnel are summarized. This work has application to radiation damage to electronics and research equipment at high energy accelerators, as well as to radiological protection. 7 refs., 4 figs

HL-LHC updates in Japan

CERN Multimedia

Antonella Del Rosso

2014-01-01

At a recent meeting in Japan, updates on the High Luminosity LHC (HL-LHC) project were presented, including the progress made so far and the deadlines still to be met for the upgraded machine to be operational from 2020.   New magnets made with advanced superconductor Nb3Sn in the framework of the HL-LHC project. These magnets are currently under construction at CERN by the TE-MSC group. The LHC is the world’s most powerful particle accelerator, and in 2015 it will reach yet another new record for the energy of its colliding beams. One key factor of its discovery potential is its ability to produce collisions described in mathematical terms by the parameter known as “luminosity”. In 2025, the HL-LHC project will allow the total number of collisions in the LHC to increase by a factor of 10. The first step in this rich upgrade programme is the delivery of the Preliminary Design Report (PDR), which is also a key milestone of the HiLumi LHC Design Study partly fund...

Analysis of the Dependability of the LHC Quench Detection System During LHC Run 2 and Further System Evolution

OpenAIRE

Podzorny, Tomasz; Calcoen, Daniel; Denz, Reiner; Siemko, Andrzej; Spasic, Jelena; Steckert, Jens

2017-01-01

The quench detection system (QDS) of the LHC superconducting circuits is an essential part of the LHC machine protection and ensures the integrity of key elements of the accelerator. The large amount of hardwired and software interlock channels of the QDS requires a very high system dependability in order to reduce the risk of affecting the successful operation of the LHC. This contribution will present methods and tools for systematic fault tracking and analysis, and will discuss recent resu...

Accelerator update

International Nuclear Information System (INIS)

Anon.

1995-01-01

When the Accelerator Conference, combined International High Energy and US Particle versions, held in Dallas in May, was initially scheduled, progress nearby for the US Superconducting Supercollider was high on the preliminary agenda. With the SSC voted down by Congress in October 1993, this was no longer the case. However the content of the meeting, in terms of both its deep implications for ambitious new projects and the breadth of its scope, showed that the worldwide particle accelerator field is far from being moribund. A traditional feature of such accelerator conferences is the multiplicity of parallel sessions. No one person can attend all sessions, so that delegates can follow completely different paths and emerge with totally different impressions. Despite this overload, and despite the SSC cancellation, the general picture is one of encouraging progress over a wide range of major new projects throughout the world. At the same time, spinoff from, and applications of, accelerators and accelerator technology are becoming increasingly important. Centrestage is now CERN's LHC proton-proton collider, where a test string of superconducting magnets is operating over long periods at the nominal LHC field of 8.36 tesla or more. The assignment of the underground areas in the existing 27- kilometre LEP tunnel is now quasidefinitive (see page 3). For CERN's existing big machine, the LEP electron-positron collider, ongoing work concentrates on boosting performance using improved optics and bunch trains. But the main objective is the LEP2 scheme using superconducting accelerating cavities to boost the beam energy (see page 6). After some initial teething problems, production and operation of these cavities appears to have been mastered, at least under test conditions. A highlight at CERN last year was the first run with lead ions (December 1994, page 15). Handling these heavy particles with systems originally designed for protons calls for ingenuity. The SPS

Accelerator update

Energy Technology Data Exchange (ETDEWEB)

Anon.

1995-09-15

When the Accelerator Conference, combined International High Energy and US Particle versions, held in Dallas in May, was initially scheduled, progress nearby for the US Superconducting Supercollider was high on the preliminary agenda. With the SSC voted down by Congress in October 1993, this was no longer the case. However the content of the meeting, in terms of both its deep implications for ambitious new projects and the breadth of its scope, showed that the worldwide particle accelerator field is far from being moribund. A traditional feature of such accelerator conferences is the multiplicity of parallel sessions. No one person can attend all sessions, so that delegates can follow completely different paths and emerge with totally different impressions. Despite this overload, and despite the SSC cancellation, the general picture is one of encouraging progress over a wide range of major new projects throughout the world. At the same time, spinoff from, and applications of, accelerators and accelerator technology are becoming increasingly important. Centrestage is now CERN's LHC proton-proton collider, where a test string of superconducting magnets is operating over long periods at the nominal LHC field of 8.36 tesla or more. The assignment of the underground areas in the existing 27- kilometre LEP tunnel is now quasidefinitive (see page 3). For CERN's existing big machine, the LEP electron-positron collider, ongoing work concentrates on boosting performance using improved optics and bunch trains. But the main objective is the LEP2 scheme using superconducting accelerating cavities to boost the beam energy (see page 6). After some initial teething problems, production and operation of these cavities appears to have been mastered, at least under test conditions. A highlight at CERN last year was the first run with lead ions (December 1994, page 15). Handling these heavy particles with systems originally designed for protons calls for ingenuity. The SPS has managed

Radiation protection issues after 20 years of LHC operation

CERN Document Server

Forkel-Wirth, D.; Roesler, S.; Theis, C.; Ulrici, L.; Vincke, H.; Vincke, Hz.

2011-01-01

Since November 2009, the LHC commissioning progresses very well, both with proton and lead beams. It will continue in 2011 and nominal LHC operation is expected to be attained in 2013. In parallel, plans for various LHC upgrades are under discussion, suggesting a High-Luminosity (HL) upgrade first and a High-Energy (HE) upgrade in a later state. Whereas the upgrade in luminosity would require the modification of only some few key accelerator components like the inner triplets, the upgrade in beam energy from 7 TeV to 16.5 TeV would require the exchange of all dipoles and of numerous other accelerator components. The paper gives an overview of the radiation protection issues related to the dismantling of LHC components prior to the installation of the HE-LHC components, i.e. after about 20 years of LHC operation. Two main topics will be discussed: (i) the exposure of workers to ionizing radiation during the dismantling of dipoles, inner triplets or collimators and experiments and (ii) the production, condition...

The last stage of LHC construction

International Nuclear Information System (INIS)

Serin, L.

2006-01-01

A few months ago the setting of the LHC (large hadron collider) machine began in the Lep's tunnel at CERN. The LHC is composed of 1200 dipole magnets that are progressively installed in the 27 km long underground circular facility, 2 universal experiments ATLAS and CMS, huge by the size of their respective detector: 40 x 20 x 20 m as well as by their number of participants: 1500 people for each one are being built in gigantic carves. All the efforts are concentrated to make every component of the machine fully installed by summer 2007 in order to get the first collisions before 2008

The LHC in numbers

CERN Multimedia

Alizée Dauvergne

2010-01-01

What makes the LHC the biggest particle accelerator in the world? Here are some of the numbers that characterise the LHC, and their equivalents in terms that are easier for us to imagine.   Feature Number Equivalent Circumference ~ 27 km   Distance covered by beam in 10 hours ~ 10 billion km a round trip to Neptune Number of times a single proton travels around the ring each second 11 245   Speed of protons first entering the LHC 299 732 500 m/s 99.9998 % of the speed of light Speed of protons when they collide 299 789 760 m/s 99.9999991 % of the speed of light Collision temperature ~ 1016 °C ove...

Slice of the LHC prototype beam tubes in dipole magnet

CERN Multimedia

1995-01-01

A slice of the LHC accelerator prototype beam tubes surrounded by magnets. The LHC will accelerate two proton beams in opposite directions. The high bending and accelerating fields needed can only be reached using superconductors. At very low temperatures superconductors have no electrical resistance and therefore no power loss. The LHC will be the largest superconducting installation ever built, a unique challenge for CERN and its industrial partners. About dipole magnets: There will be 1232 dipole magnets in the LHC, used to guide the particles around the 27 km ring. Dipole magnets must have an extremely uniform field, which means the current flowing in the coils has to be very precisely controlled. Nowhere before has such precision been achieved at such high currents. The temperature is measured to five thousandths of a degree, the current to one part in a million. The current creating the magnetic field will pass through superconducting wires at up to 12 500 amps, about 30 000 times the current flowing ...

Tunneling dynamics of superfluid Fermi gases in an accelerating optical lattice

International Nuclear Information System (INIS)

Tie Lu; Xue Jukui

2010-01-01

The nonlinear Landau-Zener tunneling and the nonlinear Rabi oscillations of superfluid Fermi gases between Bloch bands in an accelerating optical lattice are discussed. Within the hydrodynamic theory and a two-level model, the tunneling probability of superfluid Fermi gases between Bloch bands is obtained. We find that, as the system crosses from the Bose-Einstein condensation (BEC) side to the BCS side, the tunneling rate is closely related to the particle density: when the density is smaller (larger) than a critical value, the tunneling rate at unitarity is larger (smaller) than that in the BEC limit. This is well explained in terms of an effective interaction and an effective potential. Furthermore, the nonlinear Rabi oscillations of superfluid Fermi gases between the bands are discussed by imposing a periodic modulation on the level bias and the strength of the lattice. Analytical expressions of the critical density for suppressing or enhancing the Rabi oscillations are obtained. It is shown that, as the system crosses from the BEC side to the BCS side, the critical density strongly depends on the modulation parameters (i.e., the modulation amplitude and the modulation frequency). For a fixed density, a high-frequency or low-frequency modulation can suppress or enhance the Rabi oscillations both at unitarity and in the BEC limit. For an intermediate modulation frequency, the Rabi oscillations are chaotic along the entire BEC-BCS crossover, especially, on the BCS side. Interestingly, we find that the modulation of the lattice strength only with an intermediate modulation frequency has significant effect on the Rabi oscillations both in the BEC limit and at unitarity; that is, an intermediate-frequency modulation can enhance the Rabi oscillations, especially on the BCS side.

LHC preparations change gear

International Nuclear Information System (INIS)

Anon.

1995-01-01

After the formal approval by CERN Council in December (January, page 1) of the LHC protonproton collider for CERN's 27- kilometre LEP tunnel, preparations for the new machine change gear. Lyndon Evans becomes LHC Project Leader, and CERN's internal structure will soon be reorganized to take account of the project becoming a definite commitment. On the experimental side, the full Technical Proposals for the big general purpose ATLAS and CMS detectors were aired at a major meeting of the LHC Committee at CERN in January. These Technical Proposals are impressive documents each of some several hundred pages. (Summaries of the detector designs will appear in forthcoming issues of the CERN Courier.) The ALICE heavy ion experiment is not far behind, and plans for other LHC experiments are being developed. Playing an important role in this groundwork has been the Detector Research and Development Committee (DRDC), founded in 1990 to foster detector development for the LHC experimental programme and structured along the lines of a traditional CERN Experiments Committee. Established under the Director Generalship of Carlo Rubbia and initially steered by Research Director Walter Hoogland, the DRDC has done sterling work in blazing a trail for LHC experiments. Acknowledging that the challenge of LHC experimentation needs technological breakthroughs as well as specific detector subsystems, DRDC proposals have covered a wide front, covering readout electronics and computing as well as detector technology. Its first Chairman was Enzo larocci, succeeded in 1993 by Michal Turala. DRDC's role was to evaluate proposals, and make recommendations to CERN's Research Board for approval and resource allocation, not an easy task when the LHC project itself had yet to be formally approved. Over the years, a comprehensive portfolio of detector development has been built up, much of which has either led to specific LHC detector subsystems for traditional detector tasks

LHC brochure (French version)

CERN Multimedia

Marcastel, Fabienne

2014-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (English version)

CERN Multimedia

AUTHOR|(CDS)2070305

2014-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (Italian version)

CERN Multimedia

Lefevre, Christiane

2011-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (French version)

CERN Multimedia

Lefevre, C

2010-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (Danish version)

CERN Multimedia

Lefevre, C

2010-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (English version)

CERN Multimedia

Lefevre, C

2010-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (German version)

CERN Multimedia

Marcastel, Fabienne

2014-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which started up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

Powering and Machine Protection of the Superconducting LHC Accelerator

OpenAIRE

Zerlauth, M; Schmidt, R

2004-01-01

A very large number of magnets, both superconducting and conventional copper conductor magnets, are installed in the LHC (Large Hadron Collider) for the guidance of the two proton beams around the circumference. In total, the LHC counts 1614 different electrical circuits with 1712 power converters for DC powering of the superconducting and normal conducting magnets. Besides the electrical circuits connecting main magnets for bending and focusing of the two counter-rotating beams, the demandin...

LHC an unprecedented technological challenge

International Nuclear Information System (INIS)

Baruch, J.O.

2002-01-01

This article presents the future LHC (large hadron collider) in simple terms and gives some details concerning radiation detectors and supra-conducting magnets. LHC will take the place of the LEP inside the 27 km long underground tunnel near Geneva and is scheduled to operate in 2007. 8 years after its official launching the LHC project has piled up 2 year delay and has exceeded its initial budget (2 milliard euros) by 18%. Technological challenges and design difficulties are the main causes of these shifts. The first challenge has been carried out successfully, it was the complete clearing out of the LEP installation. In order to release 14 TeV in each proton-proton collision, powerful magnetic fields (8,33 Tesla) are necessary. 1248 supra-conducting 15 m-long bipolar magnets have to be built. 30% of the worldwide production of niobium-titanium wires will be used each year for 5 years in the design of these coils. The global cryogenic system will be gigantic and will use 94 tons of helium. 4 radiation detectors are being built: ATLAS (a toroidal LHC apparatus), CMS (compact muon solenoid), ALICE (a large ion collider experiment) and LHC-b (large hadron collider beauty). The 2 first will search after the Higgs boson, ALICE will be dedicated to the study of the quark-gluon plasma and LHC-b will gather data on the imbalance between matter and anti-matter. (A.C.)

Transport and installation of the LHC cryo-magnets

CERN Document Server

Artoos, K; Capatina, O; Chevalley, JM; Foraz, K; Guinchard, M; Hauviller, Claude; Kershaw, K; Prodon, S; Rühl, Ingo; Trinquart, G; Weisz, S; Ponsot, P

2007-01-01

Eleven years have passed between the beginning of transport and handling studies in 1996 and the completion of the LHC cryo-magnets installation in 2007. More than 1700 heavy, long and fragile cryo-magnets had to be transported and installed in the 27 km long LHC tunnel with very restricted available space. The size and complexity of the project involved challenges in the field of equipment design and manufacturing, maintenance, training and follow-up of operators and logistics. The paper presents the milestones, problems to be overcome and lessons learned during this project.

LHC Supertable

CERN Document Server

Pereira, M; Lamont, M; Muller, GJ; Teixeira, D D; McCrory, ES

2011-01-01

LHC operations generate enormous amounts of data. This data is being stored in many different databases. Hence, it is difficult for operators, physicists, engineers and management to have a clear view on the overall accelerator performance. Until recently the logging database, through its desktop interface TIMBER, was the only way of retrieving information on a fill-by-fill basis. The LHC Supertable has been developed to provide a summary of key LHC performance parameters in a clear, consistent and comprehensive format. The columns in this table represent main parameters that describe the collider’s operation such as luminosity, beam intensity, emittance, etc. The data is organized in a tabular fill-by-fill manner with different levels of detail. Particular emphasis was placed on data sharing by making data available in various open formats. Typically the contents are calculated for periods of time that map to the accelerator’s states or beam modes such as Injection, Stable Beams, etc. Data retrieval and ...

LHC Brochure (german version)

CERN Multimedia

Vanoli, C.

2006-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which will start-up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (German version)

CERN Multimedia

Lefevre, C

2008-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which will start-up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (German version)

CERN Multimedia

Lefevre, Christiane

2011-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which will start-up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

LHC brochure (Spanish version)

CERN Multimedia

Lefevre, C

2008-01-01

A presentation of the largest and the most powerful particle accelerator in the world, the Large Hadron Collider (LHC), which will start-up in 2008. Its role, characteristics, technologies, etc. are explained for the general public.

30 March 2009 - Representatives of the Danish Council for Independent Research Natural Sciences visiting the LHC tunnel at Point 1 with Collaboration Spokesperson F. Gianotti, Former Spokesperson P. Jenni and Transition Radiation Tracker Project Leader C. Rembser.

CERN Document Server

Maximilien Brice

2009-01-01

30 March 2009 - Representatives of the Danish Council for Independent Research Natural Sciences visiting the LHC tunnel at Point 1 with Collaboration Spokesperson F. Gianotti, Former Spokesperson P. Jenni and Transition Radiation Tracker Project Leader C. Rembser.

La cellule d'essais du LHC fonctionne avec succès pendant 24h

CERN Multimedia

CERN Press Office. Geneva

1994-01-01

On 6 and 7 December a string of powerful superconducting magnets for CERN's next particle accelerator the Large Hadron Collider (LHC) ran successfully at 8.36 Tesla for 24 hours. 8.36 Tesla is the magnetic field required to accelerate protons to the required energy for LHC and this result demonstrates that the key technical choices made for the construction of the LHC magnets were correct. The test magnets have shown that they can operate reliably under the same working conditions as the future accelerator.

LHC? Of course we’ve heard of the LHC!

CERN Multimedia

2009-01-01

Well, more or less. After its first outing in Meyrin (see last Bulletin issue), our street poll hits the streets of Divonne-les-Bains and the corridors of the University of Geneva. While many have heard of the LHC, the raison d’être of this "scientific whatsit" often remains a mystery.On first questioning, the "man-in-the-street" always pleads ignorance. "Lausanne Hockey Club?" The acronym LHC is not yet imprinted on people’s minds. "Erm, Left-Handed thingamajig?" But as soon as we mention the word "CERN", the accelerator pops straight into people’s minds. Variously referred to as "the circle" or "the ring", it makes you wonder whether people would have been so aware of the LHC if it had been shaped like a square. Size is another thing people remember: "It’s the world’s biggest. Up to now…" As for its purpose, well that’s another kettle of fish. &...

16 December 2011 - Israeli Minister of Industry, Trade and Labour S.Simhon visiting ATLAS undeground area, ATLAS visitor centre and LHC tunnel with Senior Physicist G. Mikenberg. ATLAS Collaboration Former Spokesperson is also present.

CERN Multimedia

Maximilien Brice

2011-01-01

Israeli minister of industry, trade and labour, Shalom Simhon, was welcomed in the ATLAS visitor centre before he toured the ATLAS underground experimental area, where he could see the ATLAS detector. He also had a chance to see the LHC tunnel and the CERN Control Centre.

At work on LEP, the world’s most powerful electron–positron collider

CERN Document Server

Patrice Loiez,

1999-01-01

The LHC will be built inside the same tunnel as an existing accelerator, the Large Electron Positron (LEP) collider which came on stream in 1989. LEP will be removed from the tunnel at the end of this year to make way for the LHC. Here technicians make delicate adjustments to one of LEP’s thousands of magnets.

LHC beam stability and feedback control

International Nuclear Information System (INIS)

Steinhagen, Ralph

2007-01-01

This report presents the stability and the control of the Large Hadron Collider's (LHC) two beam orbits and their particle momenta using beam-based feedback systems. The aim of this report is to contribute to a safe and reliable LHC commissioning and machine operation. The first part of the analysis gives an estimate of the expected sources of orbit and energy perturbations that can be grouped into environmental sources, machine-inherent sources and machine element failures: the slowest perturbation due to ground motion, tides, temperature fluctuations of the tunnel and other environmental influences are described in this report by a propagation model that is both qualitatively and quantitatively supported by geophone and beam motion measurements at LEP and other CERN accelerators. The second part of this analysis deals with the control of the two LHC beams' orbit and energy through automated feedback systems. Based on the reading of the more than 1056 beam position monitors (BPMs) that are distributed over the machine, a central global feedback controller calculates new deflection strengths for the more than 1060 orbit corrector magnets (CODs) that are suitable to correct the orbit and momentum around their references. this report provides an analysis of the BPMs and CODs involved in the orbit and energy feedback. The BPMs are based on a wide-band time normaliser circuit that converts the transverse beam position reading of each individual particle bunch into two laser pulses that are separated by a time delay and transmitted through optical fibres to an acquisition card that converts the delay signals into a digital position. A simple error model has been tested and compared to the measurement accuracy of LHC type BPMs, obtained through beam-based measurements in the SPS. The average beam position is controlled through 1060 superconducting and individually powered corrector dipole magnets. The proposed correction in 'time-domain' consists of a proportional

The Fire Brigade is training for the LHC

CERN Multimedia

2007-01-01

Rescue exercise at Point 8: the CERN Fire Brigade works to save a virtual victim trapped under scaffolding in the LHCb cavern.The CERN Fire Brigade really is unique. Its mission is made even more difficult by the fact that it must be capable of responding to situations underground, in many kilometres of tunnels and dozens of shafts. These specialist skills have to be honed in preparation for LHC commissioning. With a view to meeting these requirements, the "Preparing for the LHC" training course was held for the second time on 23 and 24 May. "The aim of the course is to allow the Fire Brigade to familiarise itself with and use all the resources available in the event of a problem in the tunnel", explains Gilles Colin, who is in charge of training for the CERN Fire Brigade. The two-day programme is designed to train fire Brigade members in the techniques used to free and release trapped victims. Through a series of theoretical sess...

LHC progress report

CERN Multimedia

CERN Bulletin

2010-01-01

Last weekend saw a record physics fill with a tenfold increase in instantaneous luminosity (event rate from collisions), marking an important milestone for the LHC. This physics fill did not only establish luminosities above 1.1 x 1028 cm-2 s-1 in all four experiments but was also kept in "stable beam" mode for a new record length of 30 hours. The particle physics experiments were able to more than double the total number of events so far recorded at 3.5 TeV.   The LHC screen indicating that squeezed stable beams have been achieved for the first time. The very successful weekend had been preceded by hard work on the accelerator side. A factor 5 improvement in luminosity was achieved by "squeezing" (reducing) the beam sizes at all four interaction points. This process, one of the most complex stages in the operation of the accelerator, was finalised the week before. Once the machine is "squeezed", the experimental insertions become aperture bot...

LEP sees the end of the tunnel

CERN Multimedia

2002-01-01

After 14 months, which have seen the removal of 30,000 tonnes of material from the tunnel, the LEP dismantling operation has now been completed. LHC installation, which will be subject to new safety rules, can go ahead.

LHC Olympics flex physicists' brains

CERN Multimedia

2006-01-01

Physicists from around the world met at CERN to strengthen their data-deciphering skills at the second LHC Olympics workshop. Physicists gather for the second LHC Olympics workshop. Coinciding with the kick-off of the winter Olympics in Turin, more than 70 physicists gathered at CERN from across the globe for the second LHC Olympics workshop on 9-10 February. Their challenge, however, involved brains rather than brawn. As the switch-on date for the LHC draws near, scientists excited by the project want to test and improve their ability to decipher the unprecedented amount of data that the world's biggest and most powerful particle accelerator is expected to generate. The LHC Olympics is a coordinated effort to do just that, minus the gold, silver and bronze of the athletics competition. 'In some ways, the LHC is not a precision instrument. It gives you the information that something is there but it's hard to untangle and interpret what it is,' said University of Michigan physicist Gordy Kane, who organiz...

Last cast for the LHC

CERN Multimedia

2005-01-01

The first major contract signed for the LHC is drawing to a close. Belgian firm Cockerill Sambre (a member of the Arcelor Group) has just completed production of 50,000 tonnes of steel sheets for the accelerator's superconducting magnet yokes, in what has proved to be an exemplary partnership with CERN. Philippe Lebrun, Head of the AT Department, Lyn Evans, LHC Project Leader, and Lucio Rossi, Head of the AT-MAS Group, in front of the last batch of steel for the LHC at Cockerill Sambre. It was a bright red-letter day at the end of May, when Belgian firm Cockerill Sambre of the Arcelor Group marked the completion of one of the largest contracts for the LHC machine by casting the last batch of steel sheets for the LHC superconducting magnet yokes in the presence of LHC Project Leader Lyn Evans, AT Department Head Philippe Lebrun, Magnets and Superconductors (AT-MAS) Group Leader Lucio Rossi and Head of the AT-MAS Group's components centre Francesco Bertinelli. The yokes constitute approximately 80% of the acc...

LHC computing (WLCG) past, present, and future

CERN Document Server

Bird, I G

2016-01-01

The LCG project, and the WLCG Collaboration, represent a more than 10-year investment in building and operating the LHC computing environment. This article gives some of the history of how the WLCG was constructed and the preparations for the accelerator start-up. It will discuss the experiences and lessons learned during the first 3 year run of the LHC, and will conclude with a look forwards to the planned upgrades of the LHC and the experiments, discussing the implications for computing.

Plans for the upgrade of the LHC injectors

CERN Document Server

Garoby, R; Goddard, B; Hanke, K; Meddahi, M; Vretenar, M

2011-01-01

The LHC injectors upgrade (LIU) project has been launched at the end of 2010 to prepare the CERN accelerator complex for reliably providing beam with the challenging characteristics required by the high luminosity LHC until at least 2030. Based on the work already started on Linac4, PS Booster, PS and SPS, the LIU project coordinates studies and implementation, and interfaces with the high luminosity LHC (HL-LHC) project which looks after the upgrade of the LHC itself, expected by the end of the present decade. The anticipated beam characteristics are described, as well as the status of the studies and the solutions envisaged for improving the injector performances.

Magnetization and loss measurements on Nb$_{3}$Sn and NbTi strands for ITER and LHC

CERN Document Server

Foitl, M

2001-01-01

Recent developments in high energy physics have led to a demand for high magnetic fields which cannot be generated permanently by conventional magnets wound from Cu cables. The acceleration of protons in a ring accelerator up to particle energies of several TeVs or the magnetic confinement of fusion plasmas of sufficient pressure to generate approx 1 GW of fusion power, or even more, are only two examples. To reach beam to beam collision energies of several TeV for hadrons or heavy ions, accelerator magnets have to provide very high magnetic fields which can only be produced by superconducting magnets. In the case of the Large Hadron Collider (LHC), which is planned to be commissioned in the year 2005, the circumference of the beam line is given by the dimensions of the 27 Km Large Electron Positron (LEP) Collider tunnel. Consequently each superconducting arc dipole has to provide a field of 8.36 T to bend 7 TeV protons around the ring. Apart from the total magnitude of the bending field, which necessitates t...

Magnetization and loss measurements on Nb3Sn and NbTi strands for ITER and LHC

CERN Document Server

Foitl, M

2001-01-01

Recent developments in high energy physics have led to a demand for high magnetic fields which cannot be generated permanently by conventional magnets wound from Cu cables. The acceleration of protons in a ring accelerator up to particle energies of several TeVs or the magnetic confinement of fusion plasmas of sufficient pressure to generate approx 1 GW of fusion power, or even more, are only two examples. To reach beam to beam collision energies of several TeV for hadrons or heavy ions, accelerator magnets have to provide very high magnetic fields which can only be produced by superconducting magnets. In the case of the Large Hadron Collider (LHC), which is planned to be commissioned in the year 2005, the circumference of the beam line is given by the dimensions of the 27 Km Large Electron Positron (LEP) Collider tunnel. Consequently each superconducting arc dipole has to provide a field of 8.36 T to bend 7 TeV protons around the ring. Apart from the total magnitude of the bending field, which necessitates t...

LHC Report: Beams are back in the LHC

CERN Multimedia

CERN Bulletin

2011-01-01

The LHC has shaken itself awake after the winter break, and, as the snow melts on the lower slopes, the temperature in the magnets has dropped to a chilly 1.9 K once more.   Following the cool-down, the last few weeks have seen an intense few tests of the magnets, power supplies and associated protection systems. These tests, referred to as hardware commissioning, have been completed in record time. At the same time the other accelerator systems have been put through the preparatory machine checkout. In parallel, the injectors (LINAC2, Booster, PS and SPS) have also come out of the technical stop in order to prepare to deliver beam to the LHC very early in the season. Of particular note here was the remarkably seamless transition to POPS, the PS's new main power supply system. All this work culminated in the LHC taking beam again for the first time in 2011 on Saturday, 19 February. The careful preparation paid off, with circulating beams being rapidly re-established. There then followed a programme ...

Working on an LHC dipole end-cap

CERN Multimedia

Laurent Guiraud

1999-01-01

A metal worker constructs an end-cap for an LHC dipole magnet. These magnets will be used to bend the proton beams around the LHC, which is due to start up in 2008. The handmade prototype seen here will be used to make a mold from which the final set of components will be made for the accelerator.

16 February 2012 - Chinese Taipei Ambassador to Switzerland F. Hsieh in the ATLAS visitor centre, ATLAS experimental area and LHC tunnel at Point 1 with Collaboration Deputy Sookesperson A. Lankford, throughout accompanied by International Relations Adviser R. Voss.

CERN Multimedia

Jean-Claude Gadmer

2012-01-01

16 February 2012 - Chinese Taipei Ambassador to Switzerland F. Hsieh in the ATLAS visitor centre, ATLAS experimental area and LHC tunnel at Point 1 with Collaboration Deputy Sookesperson A. Lankford, throughout accompanied by International Relations Adviser R. Voss.

28 June 2012 - Members of the European Brain Council led by President Mary Baker visiting the LHC tunnel at Point 5 with Technology Department Group Leader L. Bottura and CMS experimental area with Run Coordinator M. Chamizo-Llatas.

CERN Multimedia

Jean-Claude Gadmer

2012-01-01

28 June 2012 - Members of the European Brain Council led by President Mary Baker visiting the LHC tunnel at Point 5 with Technology Department Group Leader L. Bottura and CMS experimental area with Run Coordinator M. Chamizo-Llatas.

20 Novemnber 2013 - Ambassador of the Kingdom of the Netherlands to Switzerland B. Twaalfhoven in the LHC tunnel with CERN scientists G. De Rijk and H. Ten Kate; signing the guest book with CERN Director-General R. Heuer.

CERN Multimedia

Anna Pantelia

2013-01-01

20 Novemnber 2013 - Ambassador of the Kingdom of the Netherlands to Switzerland B. Twaalfhoven in the LHC tunnel with CERN scientists G. De Rijk and H. Ten Kate; signing the guest book with CERN Director-General R. Heuer.

14 December 2011 - Czech Republic Delegation to CERN Council and Finance Committees visiting ATLAS experimental area, LHC tunnel and ATLAS visitor centre with Former Collaboration Spokesperson P. Jenni, accompanied by Physicist R. Leitner and Swiss student A. Lister.

CERN Multimedia

Estelle Spirig

2011-01-01

14 December 2011 - Czech Republic Delegation to CERN Council and Finance Committees visiting ATLAS experimental area, LHC tunnel and ATLAS visitor centre with Former Collaboration Spokesperson P. Jenni, accompanied by Physicist R. Leitner and Swiss student A. Lister.

LHC Power Distribution

CERN Document Server

Pedersen, J

1999-01-01

The power distribution for the LHC machine and its experiments will be realised making extensive use of the existing infrastructure for the LEP. The overall power requirement is approximately the same, about 125 MW. The load distribution will however change. The even points will loose in importance and the points 1 and 5 will, due to the installation of ATLAS and CMS, gain. A thorough reorganisation of the 18 kV distribution will thus be necessary. Due to the important cryogenic installations required for the LHC, the 3.3 kV distribution system, supplying mainly cryogenic compressors, will be extended with a number of new substations. The important number of new surface buildings, underground caverns and other underground structures all will receive general service installations: Lighting and power. The new injection tunnels will require complete installations: A.C. supplies for the power converters and for general service, and D.C. cabling for the magnets of the beam line. Special safe power installations ar...

Links between astroparticle physics and the LHC

International Nuclear Information System (INIS)

Pinfold, James L

2005-01-01

Research into the fundamental nature of matter at the high energy frontier takes place in three main areas: accelerator-based particle physics, high energy astrophysics, and the cosmology of the early universe. As a consequence the study of astroparticle physics can have significant implications for collider physics at the LHC. Likewise, the LHC project provides the laboratory to perform measurements of great importance for cosmic ray astrophysics and cosmology. This paper reviews some of the important synergistic links between astroparticle and LHC physics. (topical review)

Investigation of physico-chemical processes in hypervelocity MHD-gas acceleration wind tunnels

International Nuclear Information System (INIS)

Alfyorov, V.I.; Dmitriev, L.M.; Yegorov, B.V.; Markachev, Yu.E.

1995-01-01

The calculation results for nonequilibrium physicochemical processes in the circuit of the hypersonic MHD-gas acceleration wind tunnel are presented. The flow in the primary nozzle is shown to be in thermodynamic equilibrium at To=3400 K, Po=(2∼3)x10 5 Pa, M=2 used in the plenum chamber. Variations in the static pressure due to oxidation reaction of Na, K are pointed out. The channels of energy transfer from the electric field to different degrees of freedom of an accelerated gas with Na, K seeds are considered. The calculation procedure for gas dynamic and kinetic processes in the MHD-channel using measured parameters is suggested. The calculated results are compared with the data obtained in a thermodynamic gas equilibrium assumption. The flow in the secondary nozzle is calculated under the same assumptions and the gas parameters at its exit are evaluated. Particular attention is given to the influence of seeds on flows over bodies. It is shown that the seeds exert a very small influence on the flow behind a normal shock wave. The seeds behind an oblique shock wave accelerate deactivation of vibrations of N 2 , but this effect is insignificant

LHC project. Exploring the smallest world with the highest energy beam

International Nuclear Information System (INIS)

Kondo, Takahiko; Kobayashi, Tomio

2007-01-01

The LHC accelerator at CERN will be completed soon and the experiments are about to start, making it possible to explore the TeV energy region for the first time in human history. There exists a clear reason why the TeV region is especially important for experimental exploration. The Higgs particle, the last elusive element of the Standard Model, will be discovered with very high probability. In addition there are high chances to discover signs of new physics beyond the Standard Model such as SUSY particles. Dark matter may be discovered. As an introduction of the mini-special issue for LHC, its goals and history is briefly reviewed, followed by a description on LHC accelerator, four LHC experiments as well as the contributions by Japan. (author)

Status and prospects from the LHC

International Nuclear Information System (INIS)

Hawkings, Richard

2010-01-01

This article reviews the status of the CERN Large Hadron Collider and associated experiments as of July 2010. After a brief discussion of the progress in accelerator and experiment commissioning, the LHC physics landscape is presented, together with a selection of the experimental results achieved so far. Finally the prospects for the 2010-11 LHC physics run are reviewed, with an emphasis on possible discoveries in the Higgs and supersymmetry sectors.

The latest from the LHC

CERN Multimedia

2009-01-01

Work on closing up sectors in the LHC tunnel. The foreseen shutdown work on the LHC is proceeding well, including the powering tests with the new quench protection system. However, during the past week vacuum leaks have been found in two "cold" sectors of the LHC. The leaks were found in Sectors 8-1 and 2-3 while they were being prepared for the electrical tests on the copper stabilizers at around 80 K. In both cases the leak is at one end of the sector, where the electrical feedbox, DFBA, joins Q7, the final magnet in the sector. Unfortunately, the repair necessitates a partial warm-up of both sectors. This involves the end sub-sector being warmed to room temperature, while the adjacent sub-sector "floats" in temperature and the remainder of the sector is kept at 80 K. As the leak is from the helium circuit to the insulating vacuum, the repair work will have no impact on the vacuum in the beam pipe. However the intervention wil...

The LHC enters a new phase

CERN Document Server

CERN Bulletin

2010-01-01

After achieving the world record energy of 1.18 TeV per proton beam last November, the LHC is now preparing for higher energy and luminosity.   The teams are working in the tunnel to improve the electrical reliability of the magnet protection system.   Before the 2009 running period began, all the necessary preparations to run the LHC at the collision energy of 1.18 TeV per beam had been carried out. The goal of the technical stop, which will end mid-February, is to prepare the machine for running at 3.5 TeV per beam. In order to achieve that, a current as high as 6 kAmps will have to flow into the LHC magnets. The main work is taking place on the new quench protection system (nQPS) where teams are improving the electrical reliability of the connection between the Instrumentation Feedthrough Systems (IFS) on the magnets and the nQPS equipment. There are around 500 of these connectors for each of the eight sectors in the LHC that need to be repaired. These operations are necessary to en...

Superconducting magnets for particle large accelerators

International Nuclear Information System (INIS)

Kircher, F.

1994-01-01

The different accelerator types (linear, circular) and the advantages of using superconductivity in particle accelerator are first reviewed. Characteristics of some large superconducting accelerators (Tevatron, HERA, RHIC, LHC CERN) are presented. The design features related to accelerator magnets are reviewed: magnet reproducibility, stability, field homogeneity, etc. and the selected design characteristics are discussed: manufacturing method, winding, shielding, cryostat. CEA involvement in this domain mainly addressing quadrupoles, is presented together with the Large Hadron Collider (LHC) project at CERN. Characteristics and design of detector magnets are also described. 5 figs., 2 tabs

CERN-HI-1202040 tirage 29 (front row) Russian Federation Secretary of the Security Council N. Patrushev with Adviser T. Kurtyka and Permanent Mission to the UN Adviser A. Petrov in the LHC tunnel at Point 1.

CERN Multimedia

Maximilien Brice

2012-01-01

On 14 February Nikolai Patrushev, secretary of the Security Council for the Russian Federation, was welcomed to CERN. He visited the ATLAS underground experimental area, the LHC tunnel and ATLAS Visitor Centre before viewing the Universe of Particles exhibition at the Globe of Science and Innovation.

ORBIT FEEDBACK CONTROL FOR THE LHC Prototyping at the SPS

CERN Document Server

Steinhagen, Ralph J

2004-01-01

The Large Hadron Collider (LHC) is the next generation proton collider that is presently built at CERN. The LHC will be installed in the former LEP (Large Electron Positron Collider) tunnel. The presence of a high intensity beam in an environment of cryogenic magnets requires an excellent control of particle losses from the beam. Eventually the performance of the LHC may be limited by the ability to control the beam losses. The performance of the LHC cleaning system depends critically on the beam position stability. Ground motion, field and alignment imperfections and beam manipulations may cause orbit movements. The role of the future LHC Orbit Feedback System is the minimisation of closed orbit perturbations by periodically measuring and steering the transverse beam position back to its reference position. This diploma thesis focuses on the design and prototyping of an orbit feedback system at the SPS. The design is based on a separation of the steering problem into space and time. While the correction in s...

Super and ferric: the first HL-LHC component is ready

CERN Multimedia

Antonella Del Rosso

2016-01-01

Although the actual installation phase in the tunnel will only start in 2024, the first magnet – a sextupole – of the High-Luminosity LHC (HL-LHC) is ready and working according to specifications. This first component is also rather unique as, unlike the superconducting magnets currently used in the LHC, it relies on a “superferric” heart.   An expert in the LASA Laboratory (INFN Milan, Italy) works on assembling the first sextupole corrector of the HL-LHC. (Image: INFN Milan) Although the name might sound completely unfamiliar, superferric magnets were first proposed in the 1980s as a possible solution for high-energy colliders. However, many technical problems had to be overcome before the use of superferric magnets could become a reality. In its final configuration, the HL-LHC will have 36 superferric corrector magnets, of which 4 will be quadrupoles, 8 sextupoles and 24 higher order magnets. In superferric (or “iron-dominated”) magne...

Activation Assessment of the Soil Around the ESS Accelerator Tunnel

Energy Technology Data Exchange (ETDEWEB)

Rakhno, I. L. [Fermilab; Mokhov, N. V. [Fermilab; Tropin, I. S. [Fermilab; Ene, D. [ESS, Lund

2017-01-01

Activation of the soil surrounding the ESS accelerator tunnel calculated by the MARS15 code is presented. A detailed composition of the soil, that comprises about 30 different chemical elements, is considered. Spatial distributions of the produced activity are provided in both transverse and longitudinal direction. A realistic irradiation profile for the entire planned lifetime of the facility is used. The nuclear transmutation and decay of the produced radionuclides is calculated with the DeTra code which is a built-in tool for the MARS15 code. Radionuclide production by low-energy neutrons is calculated using the ENDF/B-VII evaluated nuclear data library. In order to estimate quality of this activation assessment, a comparison between calculated and measured activation of various foils in a similar radiation environment is presented.

First H- beam accelerated at Linac4: 3MeV done, 157 MeV to go!

CERN Multimedia

Linac4 Project Team

2013-01-01

On 14 November, the first H- (one proton surrounded by two electrons) beam was accelerated to the energy of 3 MeV in the Linac4 - the new linear accelerator that will replace Linac2 as low-energy injector in the LHC accelerator chain.      A view of the Linac4 taken during the recent tests (top image) and the current measured by the instruments at the end of the acceleration line on 14 November (bottom image). Images: Linac4 collaboration. Using the recently installed Radio Frequency Quadrupole (RFQ) accelerator, 13 mA of current were accelerated to the energy of 3 MeV. After the successful commissioning of the Linac4 RFQ at the 3 MeV test stand completed during the first months of 2013, the whole equipment (composed of the RFQ itself, the following Medium Energy Beam Transport line and its diagnostic line) were moved to the Linac4 tunnel during summer and installed in their final position. In the meantime, a new ion source was assembled, installed and successfu...

LHC(ATLAS, CMS, LHCb) Run 2 commissioning status

CERN Document Server

Zimmermann, Stephanie; The ATLAS collaboration

2015-01-01

After a very successful run-1, the LHC accelerator and the LHC experiments had undergone intensive consolidation, maintenance and upgrade activities during the last 2 years in what has become known as Long-Shutdown-1 (LS1). LS1 ended in February this year, with beams back in the LHC since Easter. This talk will give a summary on the major shutdown activities of ATLAS, CMS and LHCb and review the status of commissioning for run-2 physics data taking.

Validation and Performance of the LHC Cryogenic System through Commissioning of the First Sector

CERN Document Server

Serio, L; Casas-Cubillos, J; Chakravarty, A; Claudet, S; Gicquel, F; Gomes, P; Kumar, M; Kush, PK; Millet, F; Perin, A; Rabehl, R; Singh, MR; Soubiran, M; Tavian, L

2008-01-01

The cryogenic system [1] for the Large Hadron Collider accelerator is presently in its final phase of commissioning at nominal operating conditions. The refrigeration capacity for the LHC is produced using eight large cryogenic plants and eight 1.8 K refrigeration units installed on five cryogenic islands. Machine cryogenic equipment is installed in a 26.7-km circumference ring deep underground tunnel and are maintained at their nominal operating conditions via a distribution system consisting of transfer lines, cold interconnection boxes at each cryogenic island and a cryogenic distribution line. The functional analysis of the whole system during all operating conditions was established and validated during the first sector commissioning in order to maximize the system availability. Analysis, operating modes, main failure scenarios, results and performance of the cryogenic system are presented.

The LHC and its successors

CERN Multimedia

Anaïs Schaeffer

2012-01-01

Not too long before the first long technical stop of the LHC, engineers and physicists are already working on the next generation of accelerators: HL-LHC and LHeC. The first would push proton-proton collisions to an unprecedented luminosity rate; the second would give a second wind to electron-proton collisions.   The ring-ring configuration of the LHeC would need this type of magnets, currently being studied for possible future use. In one year, the LHC will begin to change. During the first long shutdown, from December 2012 to late 2014, the machine will go through a first phase of major upgrades, with the objective of running at 7 TeV per beam at the beginning of 2015. With this long technical stop and the two others that will follow (in 2018 and 2022), a new project will see the light of day. Current plans include the study of something that looks more like a new machine rather than a simple upgrade: the High Luminosity LHC (HL-LHC). Much more powerful than the current machine, the HL-...

Hybrid beams in the LHC

CERN Multimedia

CERN Bulletin

2011-01-01

The first proton-ion beams were successfully circulated in the LHC a couple of weeks ago. Everything went so smoothly that the LHC teams had planned the first p-Pb collisions for Wednesday, 16 November. Unfortunately, a last-minute problem with a component of the PS required for proton acceleration prevented the LHC teams from making these new collisions. However, the way is open for a possible physics run with proton-lead collisions in 2012.   Members of the LHC team photographed when the first hybrid beams got to full energy. The proton and lead beams are visible on the leftmost screen up on the wall (click to enlarge the photo). The technical challenge of making different beams circulate in the LHC is by no means trivial. Even if the machine is the same, there are a number of differences when it is operated with beams of protons, beams of lead or beams of proton and lead. Provided that the beams are equal, irrespective of whether they consist of protons or lead nuclei, they revolve at the...

Experience with the Quality Assurance of the Superconducting Electrical Circuits of the LHC Machine

CERN Document Server

Bozzini, D; Kotarba, A; Mess, Karl Hubert; Olek, S; Russenschuck, Stephan

2006-01-01

The coherence between the powering reference database for the LHC and the Electrical Quality Assurance (ELQA) is guaranteed on the procedural level. However, a challenge remains the coherence between the database, the magnet test and assembly procedures, and the connection of all superconducting circuits in the LHC machine. In this paper, the methods, tooling, and procedures for the ELQA during the assembly phase of the LHC will be presented in view of the practical experience gained in the LHC tunnel. Some examples of detected polarity errors and electrical non-conformities will be presented. The parameters measured at ambient temperature, such as the dielectric insulation of circuits, will be discussed.

LHC@Home: a BOINC-based volunteer computing infrastructure for physics studies at CERN

Science.gov (United States)

Barranco, Javier; Cai, Yunhai; Cameron, David; Crouch, Matthew; Maria, Riccardo De; Field, Laurence; Giovannozzi, Massimo; Hermes, Pascal; Høimyr, Nils; Kaltchev, Dobrin; Karastathis, Nikos; Luzzi, Cinzia; Maclean, Ewen; McIntosh, Eric; Mereghetti, Alessio; Molson, James; Nosochkov, Yuri; Pieloni, Tatiana; Reid, Ivan D.; Rivkin, Lenny; Segal, Ben; Sjobak, Kyrre; Skands, Peter; Tambasco, Claudia; Veken, Frederik Van der; Zacharov, Igor

2017-12-01

The LHC@Home BOINC project has provided computing capacity for numerical simulations to researchers at CERN since 2004, and has since 2011 been expanded with a wider range of applications. The traditional CERN accelerator physics simulation code SixTrack enjoys continuing volunteers support, and thanks to virtualisation a number of applications from the LHC experiment collaborations and particle theory groups have joined the consolidated LHC@Home BOINC project. This paper addresses the challenges related to traditional and virtualized applications in the BOINC environment, and how volunteer computing has been integrated into the overall computing strategy of the laboratory through the consolidated LHC@Home service. Thanks to the computing power provided by volunteers joining LHC@Home, numerous accelerator beam physics studies have been carried out, yielding an improved understanding of charged particle dynamics in the CERN Large Hadron Collider (LHC) and its future upgrades. The main results are highlighted in this paper.

Mechanical Design of the LHC Standard Half-Cell

Science.gov (United States)

Poncet, A.; Brunet, J. C.; Cruikshank, P.; Genet, M.; Parma, V.; Rohmig, P.; Saban, R.; Tavian, L.; Veness, R.; Vlogaert, J.; Williams, L. R.

1997-05-01

The LHC Conceptual Design Report issued on 20th October 1995 (CERN/AC/95-05 (LHC) - nicknamed "Yellow Book") introduced significant changes to some fundamental features of the LHC standard half-cell, composed of one quadrupole, 3 dipoles and a set of corrector magnets. A separate cryogenic distribution line was introduced, which was previously inside the main cryostat. The dipole length has been increased from 10 to 15 m and independent powering of the focusing and defocusing quadrupole magnets was chosen. Individual quench protection diodes were introduced in magnets interconnects and many auxiliary bus bars were added to feed in series the various families of correcting superconducting magnets. The various highly intricate basic systems such as: cryostats and cryogenics feeders, superconducting magnets and their electrical feeding and protection, vacuum beam screen and its cooling, support and alignment devices have been redesigned, taking into account the very tight space available. These space constraints are given by the necessity to have maximum integral bending field strength for maximum LHC energy, and the existing LHC tunnel. Finally, cryogenic and vacuum sectorisation have been introduced to reduce downtimes and facilitate commissioning.

Future HEP Accelerators: The US Perspective

Energy Technology Data Exchange (ETDEWEB)

Bhat, Pushpalatha [Fermilab; Shiltsev, Vladimir [Fermilab

2015-11-02

Accelerator technology has advanced tremendously since the introduction of accelerators in the 1930s, and particle accelerators have become indispensable instruments in high energy physics (HEP) research to probe Nature at smaller and smaller distances. At present, accelerator facilities can be classified into Energy Frontier colliders that enable direct discoveries and studies of high mass scale particles and Intensity Frontier accelerators for exploration of extremely rare processes, usually at relatively low energies. The near term strategies of the global energy frontier particle physics community are centered on fully exploiting the physics potential of the Large Hadron Collider (LHC) at CERN through its high-luminosity upgrade (HL-LHC), while the intensity frontier HEP research is focused on studies of neutrinos at the MW-scale beam power accelerator facilities, such as Fermilab Main Injector with the planned PIP-II SRF linac project. A number of next generation accelerator facilities have been proposed and are currently under consideration for the medium- and long-term future programs of accelerator-based HEP research. In this paper, we briefly review the post-LHC energy frontier options, both for lepton and hadron colliders in various regions of the world, as well as possible future intensity frontier accelerator facilities.

The LHC demystified or how to dispel misconceptions about the accelerator

CERN Multimedia

2007-01-01

As the start-up of the LHC approaches, some people are worried about the possible dangers posed by such a powerful machine. Here are a few key points to reassure them... Drawing done by Rafel Carreras published in his book «  quand l’énergie devient matière... » This book explains particle physics and the notions of scale and energy in a simple and entertaining way. It is available in French at the CERN reception (only 5 CHF).Does your neighbour think that the LHC’s collisions will transform the pays de Gex into a huge Emmental cheese? Do you get strange e-mails warning you that you’re going to be sucked into black holes in the accelerator? Of course you know that it’s all just pure fantasy, but do you know how to reply? You can start by reading the following explanations: You are not going to be destroyed by a Big Bang... The LHC’s beams do indeed contain a lot of energy, equivalent to a TGV travelling at 150 km per ho...

A great start for the whole CERN accelerator chain

CERN Multimedia

2016-01-01

With physics data-taking under way this week at the LHC, I’d like to take a look at what’s been happening at the rest of the CERN accelerator chain.   The LHC tends to dominate the news from CERN for all kinds of reasons, beech martens included, but we should not forget that there is a unique chain of accelerators upstream of the LHC, tended to and operated by an incredible group of people. If our whole accelerator chain does not work perfectly, nor can the LHC, and in addition to forming the LHC’s injector chain, our upstream accelerators support their own experiments, bringing great diversity to the CERN research programme. The chain begins with the proton source and Linac2, which have been faithfully delivering beams since 1978. This year, Linac2 accelerated its first beams on 29 February. Beams were then passed on to the PS Booster and the veteran PS, the linchpin of the CERN accelerator complex and in operation since 1959. The final link in the chain before the ...

Status of the LHCf apparatus at LHC

CERN Document Server

Bonechi, L; Bongi, M; Castellini, G; D’Alessandro, R; Faus, A; Fukui, K; Haguenauer, M; Itow, Y; Kasahara, K; Macina, D; Mase, T; Masuda, K; Matsubara, Y; Menjo, H; Mizuishi, M; Muraki, Y; Papini, P; Perrot, A L; Ricciarini, S; Sako, T; Shimizu, Y; Taki, K; Tamura, T; Torii, S; Tricomi, A; Turner, W C; Velasco, J; Viciani, A; Yoshida, K

2009-01-01

The LHCf experiment at the LHC accelerator is ready for data taking. Both the LHCf detectors have been successfully tested and installed in their running configuration. The status of the apparatus, control software and some results of the last beam test at the SPS accelerator are presented in this work.

LHC Report: Ion Age

CERN Multimedia

John Jowett for the LHC team

2013-01-01

The LHC starts the New Year facing a new challenge: proton-lead collisions in the last month before the shutdown in mid-February.    Commissioning this new and almost unprecedented mode of collider operation is a major challenge both for the LHC and its injector chain. Moreover, it has to be done very quickly to achieve a whole series of physics goals, requiring modifications of the LHC configuration, in a very short time. These include a switch of the beam directions halfway through the run, polarity reversals of the ALICE spectrometer magnet and Van der Meer scans.    The Linac3 team kept the lead source running throughout the end-of-year technical stop, and recovery of the accelerator complex was very quick. New proton and lead beams were soon ready, with a bunch filling pattern that ensures they will eventually match up in the LHC. The LEIR machine has even attained a new ion beam intensity record.  On Friday 11 January the first single bunches o...

Reliability Analysis of the new Link between the Beam Interlock System and the LHC Beam Dumping System Zuverlässigkeitsanalyse der neuen Verbindung zwischen dem Beam Interlock System und dem LHC Beam Dumping System

CERN Document Server

Vatansever, Volkan

The nominal stored energy in each LHC beam is 360 MJ, surpassing the beam energy of other accelerators by orders of magnitude. This energy threatens to damage accelerator components in case of uncontrolled beam losses To avoid damage of accelerator equipment due to impacting beam, the controlled removal of the LHC beams from the collider rings towards the dump block must be guaranteed at all times. Therefore, the LHC Beam Dumping System was built according to high reliability standards. To further reduce the risk of incapability to dump the beams in case of correlated failures in the redundant system, a new direct link from the LHC Beam Interlock System to the Re-triggering Lines of the LHC Beam Dumping System will be implemented for the startup with beam in 2015. This link represents a diverse redundancy to the current implementation, which should neither significantly increase the risk for so-called Asynchronous Beam Dumps nor compromise machine availability. Therefore, a reliability analysis down to the co...

Reliability of the Quench Protection System for the LHC Superconducting Elements

OpenAIRE

Vergara-Fernández, A; Rodríguez-Mateos, F

2003-01-01

The huge energy stored in the Large Hadron Collider (LHC) could potentially cause severe damage when the superconducting state disappears (quench) if precautions are not taken. Most of the superconducting elements in this accelerator require protection in case of resistive transition. The reliability of the Quench Protection System will have a very important impact on the overall LHC performance. Existing high energy accelerators were conceived as prototypes whose main objective was not the e...

LHC beam stability and feedback control

Energy Technology Data Exchange (ETDEWEB)

Steinhagen, Ralph

2007-07-20

This report presents the stability and the control of the Large Hadron Collider's (LHC) two beam orbits and their particle momenta using beam-based feedback systems. The aim of this report is to contribute to a safe and reliable LHC commissioning and machine operation. The first part of the analysis gives an estimate of the expected sources of orbit and energy perturbations that can be grouped into environmental sources, machine-inherent sources and machine element failures: the slowest perturbation due to ground motion, tides, temperature fluctuations of the tunnel and other environmental influences are described in this report by a propagation model that is both qualitatively and quantitatively supported by geophone and beam motion measurements at LEP and other CERN accelerators. The second part of this analysis deals with the control of the two LHC beams' orbit and energy through automated feedback systems. Based on the reading of the more than 1056 beam position monitors (BPMs) that are distributed over the machine, a central global feedback controller calculates new deflection strengths for the more than 1060 orbit corrector magnets (CODs) that are suitable to correct the orbit and momentum around their references. this report provides an analysis of the BPMs and CODs involved in the orbit and energy feedback. The BPMs are based on a wide-band time normaliser circuit that converts the transverse beam position reading of each individual particle bunch into two laser pulses that are separated by a time delay and transmitted through optical fibres to an acquisition card that converts the delay signals into a digital position. A simple error model has been tested and compared to the measurement accuracy of LHC type BPMs, obtained through beam-based measurements in the SPS. The average beam position is controlled through 1060 superconducting and individually powered corrector dipole magnets. The proposed correction in 'time-domain' consists of a

18 December 2013 - P. Kron Chairman and Chief Executive Officer of ALSTOM signing the Guest Book with the Director-General R. Heuer and visiting the LHC tunnel at Point 1 with Technology Department Head F. Bordry. Accompanied by P. Fassnacht throughout.

CERN Multimedia

Jean-Claude Gadmer

2013-01-01

18 December 2013 - P. Kron Chairman and Chief Executive Officer of ALSTOM signing the Guest Book with the Director-General R. Heuer and visiting the LHC tunnel at Point 1 with Technology Department Head F. Bordry. Accompanied by P. Fassnacht throughout.

Senior Senator from Florida and Chairman, Senate Committee on Space, Aeronautics and Related Sciences W. Nelson, visiting the ATLAS cavern and LHC tunnel with ATLAS Collaboration Spokesperson P. Jenni and AMS Collaboration Spokesperson S.C.C.Ting, 16 March 2008.

CERN Multimedia

Maximilien Brice

2008-01-01

Senior Senator from Florida and Chairman, Senate Committee on Space, Aeronautics and Related Sciences W. Nelson, visiting the ATLAS cavern and LHC tunnel with ATLAS Collaboration Spokesperson P. Jenni and AMS Collaboration Spokesperson S.C.C.Ting, 16 March 2008.

7 May 2013 - Ambassador of the Federal Republic of Germany to Switzerland and Liechtenstein P. Gottwald and Mrs Gottwald in the ATLAS experimental cavern and LHC tunnel with Collaboration Deputy Spokesperson T. Wengler and German Scientists A. Schopper and V. Mertens.

CERN Multimedia

Maximilien Brice

2013-01-01

7 May 2013 - Ambassador of the Federal Republic of Germany to Switzerland and Liechtenstein P. Gottwald and Mrs Gottwald in the ATLAS experimental cavern and LHC tunnel with Collaboration Deputy Spokesperson T. Wengler and German Scientists A. Schopper and V. Mertens.

Rock samples from LEP/LHC tunnel excavation

CERN Multimedia

1985-01-01

Rock samples taken from 0 to 170 m below ground on the CERN site when the LEP (Large Electron Positron collider) pit number 6 was drilled in Bois-chatton (Versonnex). The challenges of LHC civil engineering: A mosaic of works, structures and workers of differents crafts and origins. Three consulting consortia for the engineering and the follow-up of the works. Four industrial consortia for doing the job. A young team of 25 CERN staff, 30 surface buildings, 32 caverns of all sizes, 170 000 m3 of concrete, 420 000 m3 excavated. 1998-2004 : six years of work and 340 millions Swiss Francs.

Modeling Open-Loop MEMS Tunneling Accelerometer Based on Circular Plate

Directory of Open Access Journals (Sweden)

Hossein Jodat Kordlar

2007-04-01

Full Text Available In this paper open-loop MEMS tunneling accelerometer was modeled based on a clamped micro circular plate with a tip tunneling at its centre. Mechanical behavior of the micro plate was studied deriving governing equation based on classic Kirchhoff thin plate theory and it was discretized using Galerkin method. Dynamic response of the proposed accelerometer due to step and harmonic external excitation was studied and the magnitude of the applied acceleration was identified by measuring of the changing of tunneling current. Obtained results show that the proposed tunneling accelerometer very sensitive and it can be measure acceleration with very high resolution but very small gap of tip tunneling limit the range of measurable acceleration.

LHC Report: Back in operation

CERN Multimedia

2016-01-01

With the machine back in their hands since Friday, 4 March, the LHC operators are now performing the powering tests on the magnets. This is a crucial step before receiving the first beams and restarting Run 2 for physics.   A Distribution Feed-Box (DFB) brings power to the LHC magnets and maintains the stability of the current in the superconducting circuits. The LHC was the last machine to be handed back to operators after the completion of maintenance work carried out during the Year-End Technical Stop (YETS) that had started on 14 December 2015. During the eleven weeks of scheduled maintenance activities, several operations took place in all the accelerators and beam lines. They included the maintenance in several points of the cryogenic system, the replacement of 18 magnets in the Super Proton Synchrotron; an extensive campaign to identify and remove thousands of obsolete cables; the replacement of the LHC beam absorbers for injection (TDIs) that are used to absorb the SPS b...

Keeping the LHC in power

CERN Multimedia

CERN Bulletin

2013-01-01

The critical safety equipment around the LHC, including the machine protection systems, is connected to Uninterruptible Power Supplies (UPS).  In case of mains failure, the UPS systems continue to power, for a limited time, these critical systems and ensure a safe shutdown of the accelerator. This week, work began to upgrade and replace over 100 UPS systems in the LHC.   The new UPS installations. For the LHC, even a perturbation on the mains is more than just an inconvenience: it often results in beam dumps and, in some cases, requires an energy extraction from superconducting circuits. When this occurs, machine protection systems, and in particular the Quench Protection System, must remain active to correctly carry out the shutdown procedure. With the UPS systems, 10 minutes of crucial power can be provided to the protection systems during this critical phase. There are currently two UPS systems in place in each one of the 32 LHC UPS zones. Originally one was used as a backup if ...

Quench Performance of the LHC Insertion Magnets

CERN Document Server

Lasheras, N C; Siemko, A; Ostojic, R; Kirby, G

2009-01-01

After final installation in the LHC tunnel, the MQM and MQY quadrupole magnets of the LHC insertions are now being commissioned to their nominal currents. These two types of magnets operate at 1.9 K and 4.5 K and with nominal currents ranging from 3600 A to 5390 A. From the very first acceptance tests of the bare magnets coming from the manufacturers, they have been powered using different cycles, in different configurations, at different temperatures and in different tests facilities. In this paper we present the global results of these powering tests. We aim at separating common from individual features of these groups of magnets. Temperature dependence of the training, temperature margin, and ultimate current can be extracted from these tests. As these magnets are used to match the optics and the dispersion in the machine, the projected ultimate current at which they can be operated is critical in view of operation of LHC.

A bit of the LHC in the mairies

CERN Multimedia

2008-01-01

As partners in the Organization’s Open Days, the communes will be given a present that is very symbolic of CERN. On Saturday, 5 April, CERN will be offering its personnel and their families preview visits to the LHC before the general public is admitted the following day. The mayors and deputy mayors of each partner commune will inaugurate the various tour routes. A CERN delegation will take the opportunity to offer the mayors a unique present to thank them for their invaluable cooperation: a 60 cm diameter section of a dipole magnet weighing almost 10 kg. The choice of present is no coincidence. It is highly symbolic since the dipoles are at the very heart of the LHC project. Each section is a faithful replica of a slice of one of the 1232 LHC dipole magnets which will be used to guide the particles around the ring. The dipoles alone occupy almost 18 km of the 27 km LHC tunnel. They are composed of superconducting cables, consisting of niobium-titanium strands with ...

Helium II heat transfer in LHC magnets : polyimide cable insulation

NARCIS (Netherlands)

Winkler, Tiemo

2017-01-01

Today’s large particle accelerators like the LHC at CERN are using superconducting materials as a construction material for magnets. These magnets need to be cooled constantly to temperatures below the critical surface of the superconducting material. In the LHC this is achieved by using liquid

LHC un defi technologique sans precedent

CERN Document Server

Baruch, J O

2002-01-01

This article presents the future LHC (large hadron collider) in simple terms and gives some details concerning radiation detectors and supra-conducting magnets. LHC will take the place of the LEP inside the 27 km long underground tunnel near Geneva and is scheduled to operate in 2007. 8 years after its official launching the LHC project has piled up 2 year delay and has exceeded its initial budget (2 milliard euros) by 18%. Technological challenges and design difficulties are the main causes of these shifts. The first challenge has been carried out successfully, it was the complete clearing out of the LEP installation. In order to release 14 TeV in each proton-proton collision, powerful magnetic fields (8,33 Tesla) are necessary. 1248 supra-conducting 15 m-long bipolar magnets have to be built. 30% of the worldwide production of niobium-titanium wires will be used each year for 5 years in the design of these coils. The global cryogenic system will be gigantic and will use 94 tons of helium. 4 radiation detect...

QCD-instantons at LHC. Theoretical aspects

International Nuclear Information System (INIS)

Petermann, M.

2007-06-01

Instantons are nonperturbative, topologically nontrivial field configurations, which occur in every nonabelian gauge theory. They can be understood as tunneling processes between topologically distinct vacua. Although being a basic theoretical aspect of the Standard Model, a direct experimental verification of instanton processes is still lacking. In this thesis the general discovery potential for QCD-instantons at the LHC is studied in detail by means of instanton perturbation theory. In this context the close correspondence between the leading instanton induced processes at HERA and at LHC becomes important. Essential aspects and differences to deep inelastic scattering can already be revealed by studying the simplest process. Based on these results inclusive cross sections are calculated including the emission of final state gluons. Compared to deep inelastic scattering, a large enhancement of the cross section is found. (orig.)

submitter LHC@Home: a BOINC-based volunteer computing infrastructure for physics studies at CERN

CERN Document Server

Barranco, Javier; Cameron, David; Crouch, Matthew; De Maria, Riccardo; Field, Laurence; Giovannozzi, Massimo; Hermes, Pascal; Høimyr, Nils; Kaltchev, Dobrin; Karastathis, Nikos; Luzzi, Cinzia; Maclean, Ewen; McIntosh, Eric; Mereghetti, Alessio; Molson, James; Nosochkov, Yuri; Pieloni, Tatiana; Reid, Ivan D; Rivkin, Lenny; Segal, Ben; Sjobak, Kyrre; Skands, Peter; Tambasco, Claudia; Van der Veken, Frederik; Zacharov, Igor

2017-01-01

The LHC@Home BOINC project has provided computing capacity for numerical simulations to researchers at CERN since 2004, and has since 2011 been expanded with a wider range of applications. The traditional CERN accelerator physics simulation code SixTrack enjoys continuing volunteers support, and thanks to virtualisation a number of applications from the LHC experiment collaborations and particle theory groups have joined the consolidated LHC@Home BOINC project. This paper addresses the challenges related to traditional and virtualized applications in the BOINC environment, and how volunteer computing has been integrated into the overall computing strategy of the laboratory through the consolidated LHC@Home service. Thanks to the computing power provided by volunteers joining LHC@Home, numerous accelerator beam physics studies have been carried out, yielding an improved understanding of charged particle dynamics in the CERN Large Hadron Collider (LHC) and its future upgrades. The main results are highlighted i...

The Fluka Linebuilder and Element Database: Tools for Building Complex Models of Accelerators Beam Lines

CERN Document Server

Mereghetti, A; Cerutti, F; Versaci, R; Vlachoudis, V

2012-01-01

Extended FLUKA models of accelerator beam lines can be extremely complex: heavy to manipulate, poorly versatile and prone to mismatched positioning. We developed a framework capable of creating the FLUKA model of an arbitrary portion of a given accelerator, starting from the optics configuration and a few other information provided by the user. The framework includes a builder (LineBuilder), an element database and a series of configuration and analysis scripts. The LineBuilder is a Python program aimed at dynamically assembling complex FLUKA models of accelerator beam lines: positions, magnetic fields and scorings are automatically set up, and geometry details such as apertures of collimators, tilting and misalignment of elements, beam pipes and tunnel geometries can be entered at user’s will. The element database (FEDB) is a collection of detailed FLUKA geometry models of machine elements. This framework has been widely used for recent LHC and SPS beam-machine interaction studies at CERN, and led to a dra...

Off-momentum collimation and cleaning in the energy ramp in the LHC

CERN Document Server

Quaranta, Elena; Giulini Castiglioni Agosteo, Stefano Luigi Maria

This Master thesis work has been carried out at CERN in the framework of the LHC (Large Hadron Collider) Collimation project. The LHC is a two-beam proton collider, built to handle a stored energy of 360MJ for each beam. Since the energy deposition from particle losses could quench the superconducting magnets, a system of collimators has been installed in two cleaning insertions in the ring and in the experimental areas. The achievable LHC beam intensity is directly coupled to the beam loss rate and, consequently, to the cleaning eciency of the collimation system. This study analyses the collimation cleaning performance in dierent scenarios inside the accelerator. First, simulations are performed of the transverse losses in the LHC collimation system during the acceleration process. The results are compared with data taken during a dedicated session at the LHC machine. Simulations are also performed to predict the collimation eciency during future operation at higher energy. Furthermore, an investigation of t...

Charged vector particle tunneling from a pair of accelerating and rotating and 5D gauged super-gravity black holes

Energy Technology Data Exchange (ETDEWEB)

Javed, Wajiha; Ali, Riasat [University of Education, Division of Science and Technology, Lahore (Pakistan); Abbas, G. [The Islamia University of Bahawalpur, Department of Mathematics, Bahawalpur (Pakistan)

2017-05-15

The aim of this paper is to study the quantum tunneling process for charged vector particles through the horizons of more generalized black holes by using the Proca equation. For this purpose, we consider a pair of charged accelerating and rotating black holes with Newman-Unti-Tamburino parameter and a black hole in 5D gauged super-gravity theory, respectively. Further, we study the tunneling probability and corresponding Hawking temperature for both black holes by using the WKB approximation. We find that our analysis is independent of the particles species whether or not the background black hole geometries are more generalized. (orig.)

Superconducting magnet development for the LHC upgrades

International Nuclear Information System (INIS)

Rossi, Lucio

2012-01-01

LHC is now delivering proton and heavy ion collisions at the highest energy. Upgrading the LHC beyond its design performance is a long term program that started during the LHC construction, with some fundamental R and D programs. The upgrade program is based on a vigorous superconductor and magnet R and D, aimed at increasing the field in accelerator magnets from 8 T to 12 T for the luminosity upgrade, with the scope of increasing the collider luminosity by a factor 5 to 10 from 2022. The upgrade program might continue with the LHC energy upgrade, which would require magnets producing field in the range of 16-20 T. The results obtained so far and the future challenges are discussed together with the possible plan to reach the goals. (author)

Mutual seismic interaction between tunnels and the surrounding granular soil

Directory of Open Access Journals (Sweden)

Mohamed Ahmed Abdel-Motaal

2014-12-01

Study results show that the maximum exerted straining actions in tunnel lining are directly proportional to the relative stiffness between tunnel and surrounding soil (lining thickness and soil shear modulus. Moreover, it is highly affected by the peak ground acceleration and the tunnel location (embedment depth. A comprehensive study is performed to show the effect of tunnel thickness and tunnel diameter on both the induced bending moment and lining deformation. In general, it is concluded that seismic analysis should be considered in regions subjected to peak ground acceleration greater than 0.15g.

Remote Qualification of HLS and WPS Systems in the LHC Tunnel

CERN Document Server

Mainaud Durand, Helene; Marin, Antonio; Rousseau, Michel; Sosin, Mateusz

2014-01-01

The position of the inner triplets of the LHC is monitored using Hydrostatic Levelling System (HLS) and Wire Positioning System (WPS). A regulation of these systems is needed to guarantee the sensors’ function. Such a regulation was done in-situ up to now, but the level of residual radiation at the level of the inner triplets will significantly increase with the next steps of LHC operation. Two systems have been designed to perform such a remote qualification: a filling/purging system for the HLS system and a wire displacer system for the WPS. In the paper, the requirements and the solutions proposed are described, with the emphasis on the conceptual design and the results obtained.

Particles are back in the LHC

CERN Multimedia

CERN Bulletin

2016-01-01

The LHC has introduced beam for the first time since the year-end technical stop began in December 2015.   CERN Management and LHC operators applaud as the first beam circulates in the LHC, on Friday 25 March.   On Friday, the LHC opened its doors to allow particles to travel around the ring for the first time since the year-end technical stop (YETS) began in December 2015. At 10:30 a.m., a first bunch was circulating and by midday the beam was circulating in both directions. Progress over the weekend has been good and low intensity beam has already been taken to 6.5 TeV and through the squeeze. Last week, the LHC underwent the final phase of preparation before beam -known as the machine checkout. During this phase all the systems of the LHC are put through their paces without beam. A key part of the process is driving the magnetic circuits, radiofrequency accelerating cavities, collimators, transverse dampers etc. repeatedly through the nominal LHC cycle. A fu...

LHC Power Converters: A Precision Game

CERN Multimedia

2001-01-01

The LHC test-bed, String 2, is close to commissioning and one important element to get a first chance to prove what it can do is the power converter system. In String 2 there are 16 converters, in the full LHC there will be almost 1800. This article takes a look at what is so special about the power converters for the LHC. The 13 000 Amps power converters with the watercooled cables going to the String 2 feedboxes. The LHC's superconducting magnets will be the pinnacle of high technology. But to work, they'll need the help of high-precision power converters to supply them with extremely stable DC current. Perfection will be the name of the game, with an accuracy of just 1-2 parts per million (ppm) required. LEP, for the sake of comparison, could live with 10-20 ppm. The LHC's power converters will be very different from those of LEP or the SPS since the new accelerator's magnets are mostly superconducting. That means that they require much higher currents at a lower voltage since superconductors have no re...

The beam dump tunnels

CERN Multimedia

Patrice Loïez

2002-01-01

In these images workers are digging the tunnels that will be used to dump the counter-circulating beams. Travelling just a fraction under the speed of light, the beams at the LHC will each carry the energy of an aircraft carrier travelling at 12 knots. In order to dispose of these beams safely, a beam dump is used to extract the beam and diffuse it before it collides with a radiation shielded graphite target.

15 February 2012 - Geneva United Nations Office Director-General K.-J. Tokayev in the LHC tunnel with Adviser for Relations with international organisations M. Bona and Technology Department Head F. Bordry.

CERN Multimedia

Jean-claude Gadmer

2012-01-01

Kassym-Jomart Tokayev, director-general of the United Nations Office at Geneva, (centre picture 02), visited CERN on 15 February. He toured the LHC tunnel with Maurizio Bona, CERN’s adviser to the director-general, relations with international organizations, left, and Frédérick Bordry, CERN’s technology department head. He also visited the ATLAS underground experimental area, as well as the exhibition at the Globe of Science and Innovation.

The LHC cryogenic system and operational experience from the first three years run

International Nuclear Information System (INIS)

Delikaris, Dimitri; Tavian, Laurent

2014-01-01

The LHC (Large Hadron Collider) accelerator helium cryogenic system consists of eight cryogenically independent sectors, each 3.3 km long, all cooled and operated at 1.9 K. The overall, entropy equivalent, installed cryogenic capacity totalizes 144 kW (a) 4.5 K including 19.2 kW (a) 1.8 K with an associated helium inventory of 130 ton. The LHC cryogenic system is considered among the most complex and powerful in the world allowing the cooling down to superfluid helium temperature of 1.9 K. of the accelerators' high field superconducting magnets distributed over the 26.7 km underground ring. The present article describes the LHC cryogenic system and its associated cryogen infrastructure. Operational experience, including cryogen management, acquired from the first three years of LHC operation is finally presented. (author)

Vacuum vessels for the LHC magnets arrive at CERN

CERN Multimedia

2001-01-01

The first batch of pre-series vacuum vessels for the LHC dipole magnets has just been delivered to CERN. The vessels are components of the cryostats and will provide the thermal insulation for the superconducting magnets. The first batch of vacuum vessels for the LHC dipole magnets with the team taking part at CERN in ordering and installing them. Left to right : Claude Hauviller, Monique Dupont, Lloyd Williams, Franck Gavin, Alain Jacob, Christophe Vuitton, Davide Bozzini, Laure Sandri, Mikael Sjoholm and André de Saever. In 2006 all that will be seen of the LHC superconducting dipoles in the LHC tunnel will be a line of over 1230 blue cylindrical vacuum vessels. Ten vessels, each weighing 4 tonnes, are already at CERN. On 6 July the first batch of pre-series vessels reached the Lab-oratory from the firm SIMIC Spa whose works are near Savona in north-western Italy. Despite appearances, these 15-metre long, 1-metre diameter blue tubes are much more sophisticated than sections of a run-of-the-mill...

Mobilizing for the LHC

CERN Multimedia

2008-01-01

A follow-up report on the incident that occurred in LHC Sector 3-4 was published on 5 December. It confirms that the accelerator will be restarted in the summer of 2009. From now until then, the teams will be pulling out all the stops to repair the sector and enhance the operational safety of the machine.

An operational event announcer for the LHC control centre using speech synthesis

International Nuclear Information System (INIS)

Page, S.; Alemany Fernandez, R.

2012-01-01

The LHC Island of the CERN Control Centre is a busy working environment with many status displays and running software applications. An audible event announcer was developed in order to provide a simple and efficient method to notify the operations team of events occurring within the many subsystems of the accelerator. The LHC Announcer uses speech synthesis to report messages based upon data received from multiple sources. General accelerator information such as injections, beam energies and beam dumps are derived from data received from the LHC Timing System. Additionally, a software interface is provided that allows other surveillance processes to send messages to the Announcer using the standard control system middle-ware. Events are divided into categories which the user can enable or disable depending upon their interest. Use of the LHC Announcer is not limited to the Control Centre and is intended to be available to a wide audience, both inside and outside CERN. To accommodate this, it was designed to require no special software beyond a standard web browser. This paper describes the design of the LHC Announcer and how it is integrated into the LHC operational environment. (authors)

LHC Report

CERN Multimedia

CERN Bulletin

2010-01-01

During last week the commissioning effort has been devoted to beam development work, required to accelerate beams with nominal bunch intensity to 3.5 TeV. Significant progress has been done with the commissioning of the systems required to control the beam size and bunch length during the ramp and accelerate the beam with reproducible characteristics. The setting-up of the collimation system for the operation with higher intensity is presently ongoing with the aim of delivering physics with nominal bunch intensity towards the end of next week. For more information about the LHC and a video of the presentation recently done by LHC operators, please visit: http://lpcc.web.cern.ch/LPCC/ http://indico.cern.ch/categoryDisplay.py?categId=2687

Accelerators

CERN Multimedia

CERN. Geneva

2001-01-01

The talk summarizes the principles of particle acceleration and addresses problems related to storage rings like LEP and LHC. Special emphasis will be given to orbit stability, long term stability of the particle motion, collective effects and synchrotron radiation.

LHC opening delayed, operating schedule extended

CERN Multimedia

2009-01-01

"The Large Hadron Collider (LHC) will reportedly reopen in October rather than this summer [...]. The $ 6.5 billion particle accelerator has 1'232 superconducting dipole magnets out of a total of more than 1'700 large magnets" (0.5 page)

First beam splashes at the LHC

CERN Multimedia

CERN Bulletin

2015-01-01

After a two-year shutdown, the first beams of Run 2 circulated in the LHC last Sunday. On Tuesday, the LHC operators performed dedicated runs to allow some of the experiments to record their first signals coming from particles splashed out when the circulating beams hit the collimators. Powerful reconstruction software then transforms the electronic signals into colourful images.     “Splash” events are used by the experiments to test their numerous subdetectors and to synchronise them with the LHC clock. These events are recorded when the path of particles travelling in the LHC vacuum pipe is intentionally obstructed using collimators – one-metre-long graphite or tungsten jaws that are also used to catch particles that wander too far from the beam centre and to protect the accelerator against unavoidable regular and irregular beam losses. The particles sprayed out of the collision between the beam and the collimators are mostly muons. ATLAS and CMS&...

The LHC Collimator Controls Architecture - Design and beam tests

CERN Document Server

Redaelli, S; Gander, P; Jonker, M; Lamont, M; Losito, R; Masi, A; Sobczak, M

2007-01-01

The LHC collimation system will require simultaneous management by the LHC control system of more than 500 jaw positioning mechanisms in order to ensure the required beam cleaning and machine protection performance in all machine phases, from injection at 450 GeV to collision at 7 TeV. Each jaw positionis a critical parameter for the machine safety. In this paper, the architecture of the LHC collimator controls is presented. The basic design to face the accurate control of the LHC collimators and the interfaces to the other components of LHC Software Application and control infrastructures are described. The full controls system has been tested in a real accelerator environment in the CERN SPS during beam tests with a full scale collimator prototype. The results and the lessons learned are presented.

Stephen Myers - More collaboration for accelerators

CERN Multimedia

2009-01-01

Stephen Myers has been appointed Director of Accelerators and Technology. His highest priority is to get the LHC running this year, but beyond that he also has the difficult task of balancing resources between non-LHC physics, new projects and consolidation of the existing accelerators. Stephen Myers, previous head of the Accelerator and Beams (AB) Department, will now oversee all the accelerator and technology activities at CERN, including the Beams, Technology and Engineering departments, in the re-established position of Director of Accelerators and Technology. "There are several good reasons to have a single person responsible for the CERN accelerators and technology," said Myers. "Most importantly, this will allow closer collaboration between the three departments and provide the structure for possible redeployment of resources. There will, of course, be regular meetings between the heads of department and myself, and if proble...

6 February 2012 - Supreme Audit Institutions from Norway, Poland, Spain and Switzerland visiting the LHC tunnel at Point 5, CMS underground experimental area, CERN Control Centre and LHC superconducting magnet test hall. Delegations are throughout accompanied by Swiss P. Jenni, Polish T. Kurtyka, Spanish J. Salicio, Norwegian S. Stapnes and International Relations Adviser R. Voss. (Riksrevisjonen, Oslo; Tribunal de Cuentas , Madrid; the Court of Audit of Switzerland and Najwyzsza Izba Kontroli, Varsaw)

CERN Multimedia

Jean-Claude Gadmer

2012-01-01

6 February 2012 - Supreme Audit Institutions from Norway, Poland, Spain and Switzerland visiting the LHC tunnel at Point 5, CMS underground experimental area, CERN Control Centre and LHC superconducting magnet test hall. Delegations are throughout accompanied by Swiss P. Jenni, Polish T. Kurtyka, Spanish J. Salicio, Norwegian S. Stapnes and International Relations Adviser R. Voss. (Riksrevisjonen, Oslo; Tribunal de Cuentas , Madrid; the Court of Audit of Switzerland and Najwyzsza Izba Kontroli, Varsaw)

Theoretical Modeling and Experimental Investigation of the Thermal Performance of the LHC Prototype Lattice Cryostats

CERN Document Server

Riddone, G

1997-01-01

This thesis presents the thermal performance of the LHC (Large Hadron Collider) prototype cryostats both in steady-state and in transient conditions. LHC will be built in the 27 km LEP tunnel and will provide proton-proton collisions. It will make use of superconducting magnets operating in static bath of superfluid helium at 1.9 K. The thesis is mainly divided in three parts. The first part cont ains three chapters which present a brief overview of the LHC project. Part 1-Chapter 1 gives a short introduction to the LHC design layout and performance. Part 1-Chapter 2 refers to LHC cryogenic s ystem and describes the general architecture of the cryogenic plants, the temperature levels and the heat loads. The 50 m long LHC prototype half-cell contains one twin-bore quadrupole and four twin-a perture dipoles. In Part 1-Chapter 3 the design and construction of the prototype dipole and quadrupole cryostats are presented. The LHC prototype cryostats have integrated cryogenic lines, while the final LHC cryostats hav...

Expected damage to accelerator equipment due to the impact of the full LHC beam: beam instrumentation, experiments and simulations

CERN Document Server

Burkart, Florian

The Large Hadron Collider (LHC) is the biggest and most powerful particle accelerator in the world, designed to collide two proton beams with particle momentum of 7 TeV/c each. The stored energy of 362MJ in each beam is sufficient to melt 500 kg of copper or to evaporate about 300 liter of water. An accidental release of even a small fraction of the beam energy can cause severe damage to accelerator equipment. Reliable machine protection systems are necessary to safely operate the accelerator complex. To design a machine protection system, it is essential to know the damage potential of the stored beam and the consequences in case of a failure. One (catastrophic) failure would be, if the entire beam is lost in the aperture due to a problem with the beam dumping system. This thesis presents the simulation studies, results of a benchmarking experiment, and detailed target investigation, for this failure case. In the experiment, solid copper cylinders were irradiated with the 440GeV proton beam delivered by the ...

Cryogenic Studies for the Proposed CERN Large Hadron Electron Collider (LHeC)

CERN Document Server

Haug, F

2011-01-01

The LHeC (Large Hadron electron Collider) is a proposed future colliding beam facility for lepton-nucleon scattering particle physics at CERN. A new 60 GeV electron accelerator will be added to the existing 27 km circumference 7 TeV LHC for collisions of electrons with protons and heavy ions. Two basic design options are being pursued. The first is a circular accelerator housed in the existing LHC tunnel which is referred to as the "Ring-Ring" version. Low field normal conducting magnets guide the particle beam while superconducting (SC) RF cavities cooled to 2 K are installed at two opposite locations at the LHC tunnel to accelerate the beams. For this version in addition a 10 GeV re-circulating SC injector will be installed. In total four refrigerators with cooling capacities between 1.2 kW and 3 kW @ 4.5 K are needed. The second option, referred to as the "Linac-Ring" version consists of a race-track re-circulating energy-recovery type machine with two 1 km long straight acceleration sections. The 944 hi...

The first LHC insertion quadrupole

CERN Multimedia

2004-01-01

An important milestone was reached in December 2003 at the CERN Magnet Assembly Facility. The team from the Accelerator Technology - Magnet and Electrical Systems group, AT-MEL, completed the first special superconducting quadrupole for the LHC insertions which house the experiments and major collider systems. The magnet is 8 metres long and contains two matching quadrupole magnets and an orbit corrector, a dipole magnet, used to correct errors in quadrupole alignment. All were tested in liquid helium and reached the ultimate performance criteria required for the LHC. After insertion in the cryostat, the superconducting magnet will be installed as the Q9 quadrupole in sector 7-8, the first sector of the LHC to be put in place in 2004. Members of the quadrupole team, from the AT-MEL group, gathered around the Q9 quadrupole at its inauguration on 12 December 2003 in building 181.

Commissioning of the Cryogenics of the LHC Long Straight Sections

CERN Document Server

Perin, A; Claudet, S; Darve, C; Ferlin, G; Millet, F; Parente, C; Rabehl, R; Soubiran, M; van Weelderen, R; Wagner, U

2010-01-01

The LHC is made of eight circular arcs interspaced with eight Long Straight Sections (LSS). Most powering interfaces to the LHC are located in these sections where the particle beams are focused and shaped for collision, cleaning and acceleration. The LSSs are constituted of several unique cryogenic devices and systems like electrical feed-boxes, standalone superconducting magnets, superconducting links, RF cavities and final focusing superconducting magnets. This paper presents the cryogenic commissioning and the main results obtained during the first operation of the LHC Long Straight Sections.

Commissioning of the cryogenics of the LHC long straight sections

International Nuclear Information System (INIS)

Perin, A.; Casas-Cubillos, J.; Claudet, S.; Darve, C.; Ferlin, G.; Millet, F.; Parente, C.; Rabehl, R.; Soubiran, M.; van Weelderen, R.; Wagner, U.

2010-01-01

The LHC is made of eight circular arcs interspaced with eight Long Straight Sections (LSS). Most powering interfaces to the LHC are located in these sections where the particle beams are focused and shaped for collision, cleaning and acceleration. The LSSs are constituted of several unique cryogenic devices and systems like electrical feed-boxes, standalone superconducting magnets, superconducting links, RF cavities and final focusing superconducting magnets. This paper presents the cryogenic commissioning and the main results obtained during the first operation of the LHC Long Straight Sections.

Machine Protection Issues and Strategies for the LHC

CERN Multimedia

Schmidt, R

2004-01-01

For nominal beam parameters at 7 TeV/c, each of the two LHC proton beams has a stored energy of 350 MJ threatening to damage accelerator equipment in case of uncontrolled beam loss. The energy stored in the magnet system at 7 TeV/c will exceed 10 GJ. In order to avoid damage of accelerator equipment, operation of the LHC will be strongly constrained. For the first commissioning of the complex magnet powering, quench protection and powering interlock systems must be fully operational. For safe injection, beam absorbers must be in the correct position and specific procedures for safe injection have to be applied. Since the beam dump blocks are the only element of the LHC that can withstand the impact of the full beam, it is essential that the beams are properly extracted onto the dump blocks at the end of a fill and in case of emergency. The time constants for failures leading to beam loss extend from some µs to few seconds. Requirements for safe operation throughout the cycle necessitate the use of beam instr...

Powering and Machine Protection of the Superconducting LHC Accelerator

CERN Document Server

Zerlauth, M

2004-01-01

A very large number of magnets, both superconducting and conventional copper conductor magnets, are installed in the LHC (Large Hadron Collider) for the guidance of the two proton beams around the circumference. In total, the LHC counts 1614 different electrical circuits with 1712 power converters for DC powering of the superconducting and normal conducting magnets. Besides the electrical circuits connecting main magnets for bending and focusing of the two counter-rotating beams, the demanding requirements on the quality of the magnetic fields require a large number of circuits for corrector magnets distributed around the circumference. In total, more than 10000 magnets will need to be connected to the power converters via a large inventory of electrical components such as normal conducting cables and tubes, energy extraction systems, current feedthroughs and superconducting busbars. Depending on the complexity and importance of these electrical circuits and their components, various systems will interact for...

The first LHC sector is fully interconnected

CERN Multimedia

2006-01-01

Sector 7-8 is the first sector of the LHC to become fully operational. All the magnets, cryogenic line, vacuum chambers and services are interconnected. The cool down of this sector can soon commence. LHC project leader Lyn Evans, the teams from CERN's AT/MCS, AT/VAC and AT/MEL groups, and the members of the IEG consortium celebrate the completion of the first LHC sector. The 10th of November was a red letter day for the LHC accelerator teams, marking the completion of the first sector of the machine. The magnets of sector 7-8, together with the cryogenic line, the vacuum chambers and the distribution feedboxes (DFBs) are now all completely interconnected. Sector 7-8 has thus been closed and is the first LHC sector to become operational. The interconnection work required several thousand electrical, cryogenic and insulating connections to be made on the 210 interfaces between the magnets in the arc, the 30 interfaces between the special magnets and the interfaces with the cryogenic line. 'This represent...

Assembly and Test of SQ01b, a Nb3Sn Quadrupole Magnet for the LHC Accelerator Research Program

International Nuclear Information System (INIS)

Ferracin, P.; Ambrosio, G.; Bartlett, S. E.; Bordini, B.; Carcagno, R.H.; Caspi, S.; Dietderich, D.R.; Feher, S.; Gourlay, S.A.; Hafalia, A.R.; Lamm, M.J.; Lietzke, A.F.; Mattafirri, S.; McInturff, A.D.; Orris, D.F.; Pischalnikov, Y.M.; Sabbi, G.L.; Sylvester, C.D.; Tartaglia, M.A.; Velev, G.V.; Zlobin, A.V.; Kashikhin, V.V.

2006-01-01

The US LHC Accelerator Research Program (LARP) consists of four US laboratories (BNL, FNAL, LBNL, and SLAC) collaborating with CERN to achieve a successful commissioning of the LHC and to develop the next generation of Interaction Region magnets. In 2004, a large aperture Nb 3 Sn racetrack quadrupole magnet (SQ01) has been fabricated and tested at LBNL. The magnet utilized four subscale racetrack coils and was instrumented with strain gauges on the support structure and directly over the coil's turns. SQ01 exhibited training quenches in two of the four coils and reached a peak field in the conductor of 10.4 T at a current of 10.6 kA. After the test, the magnet was disassembled, inspected with pressure indicating films, and reassembled with minor modifications. A second test (SQ01b) was performed at FNAL and included training studies, strain gauge measurements and magnetic measurements. Magnet inspection, test results, and magnetic measurements are reported and discussed, and a comparison between strain gauge measurements and 3D finite element computations is presented

Assembly and Test of SQ01b, a Nb3Sn Quadrupole Magnet for the LHC Accelerator Research Program

Energy Technology Data Exchange (ETDEWEB)

Ferracin, P.; Ambrosio, G.; Bartlett, S. E.; Bordini, B.; Carcagno, R.H.; Caspi, S.; Dietderich, D.R.; Feher, S.; Gourlay, S.A.; Hafalia, A.R.; Lamm, M.J.; Lietzke, A.F.; Mattafirri, S.; McInturff, A.D.; Orris, D.F.; Pischalnikov, Y.M.; Sabbi, G.L.; Sylvester, C.D.; Tartaglia, M.A.; Velev, G.V.; Zlobin, A.V.; Kashikhin, V.V.

2006-06-01

The US LHC Accelerator Research Program (LARP) consists of four US laboratories (BNL, FNAL, LBNL, and SLAC) collaborating with CERN to achieve a successful commissioning of the LHC and to develop the next generation of Interaction Region magnets. In 2004, a large aperture Nb{sub 3}Sn racetrack quadrupole magnet (SQ01) has been fabricated and tested at LBNL. The magnet utilized four subscale racetrack coils and was instrumented with strain gauges on the support structure and directly over the coil's turns. SQ01 exhibited training quenches in two of the four coils and reached a peak field in the conductor of 10.4 T at a current of 10.6 kA. After the test, the magnet was disassembled, inspected with pressure indicating films, and reassembled with minor modifications. A second test (SQ01b) was performed at FNAL and included training studies, strain gauge measurements and magnetic measurements. Magnet inspection, test results, and magnetic measurements are reported and discussed, and a comparison between strain gauge measurements and 3D finite element computations is presented

Fast Beam Current Change Monitor for the LHC

CERN Document Server

Kral, Jan

Stringent demands on the LHC safety and protection systems require improved methods of detecting fast beam losses. The Fast Beam Current Transformer (FBCT) is a measurement instrument, providing information about bunch-to-bunch intensity of the accelerated beam. This thesis describes the development of a new protection system based on the FBCT signal measurements. This system, the Fast Beam Current Change Monitor (FBCCM), measures the FBCT signal in a narrow frequency band and computes time derivation of the beam signal magnitude. This derivation is proportional to the beam losses. When the losses exceed a certain level, the FBCCM requests a beam dump in order to protect the LHC. The LHC protection will be ensured by four FBCCMs which will be installed into the LHC in July 2014. Six FBCCMs have been already constructed and their characteristics were measured with satisfactory results. The FBCCMs were tested by a laboratory simulation of the real LHC environment.

An Operational Event Announcer for the LHC Control Centre Using Speech Synthesis

CERN Document Server

Page, S

2011-01-01

The LHC Island of the CERN Control Centre is a busy working environment with many status displays and running software applications. An audible event announcer was developed in order to provide a simple and efficient method to notify the operations team of events occurring within the many subsystems of the accelerator. The LHC Announcer uses speech synthesis to report messages based upon data received from multiple sources. General accelerator information such as injections, beam energies and beam dumps are derived from data received from the LHC Timing System. Additionally, a software interface is provided that allows other surveillance processes to send messages to the Announcer using the standard control system middleware. Events are divided into categories which the user can enable or disable depending upon their interest. Use of the LHC Announcer is not limited to the Control Centre and is intended to be available to a wide audience, both inside and outside CERN. To accommodate this, it...

Spring 
start-up for the LHC

CERN Multimedia

2007-01-01

A new schedule for the commissioning of the LHC was presented to the Council at its Session in June. The start-up of the accelerator is scheduled for May 2008, to allow all technical problems to be resolved.

Transverse emittance measurement and preservation at the LHC

Energy Technology Data Exchange (ETDEWEB)

Kuhn, Maria

2016-06-20

The Large Hadron Collider (LHC) at CERN is a high energy storage ring that provides proton and heavy ion collisions to study fundamental particle physics. The luminosity production is closely linked to emittance preservation in the accelerator. The transverse emittance is the phase space density of the beam and should be conserved when the particle beam is transformed through the accelerator. Perturbing effects, however, can lead to emittance increase and hence luminosity degradation. Measuring the emittance growth is a complex task with high intensity beams and changing energies. The machine optics and the transverse beam size have to be measured as accurately as possible. Beta function measurements with k-modulation are discussed. With this method the quadrupole focussing strength is varied and the resulting tune change is traced to determine the beta function at the quadrupole. A new k-modulation measurement tool was developed for the LHC. The fully automatic and online measurement system takes constraints of various systems such as tune measurement precision and powering limitations of the LHC superconducting circuits into account. With sinusoidal k-modulation record low beta function measurement uncertainties in the LHC have been reached. 2015 LHC beta function and β*, which is the beta function at the collision point, measurements with k-modulation will be presented. Wire scanners and synchrotron light monitors are presently used in the LHC to measure the transverse beam size. Accuracy and limitations of the LHC transverse profile monitors are discussed. During the 2012 LHC proton run it was found that wire scanner photomultiplier saturation added significant uncertainty on all measurements. A large discrepancy between emittances from wire scanners and luminosity was discovered but not solved. During Long Shutdown 1 the wire scanner system was upgraded with new photomultipliers. A thorough study of LHC wire scanner measurement precision in 2015 is presented

Performance of the Protection System for Superconducting Circuits during LHC Operation

OpenAIRE

Denz, R; Charifoulline, Z; Dahlerup-Petersen, K; Schmidt, R; Siemko, A; Steckert, J

2011-01-01

The protection system for superconducting magnets and bus-bars is an essential part of the LHC machine protection and ensures the integrity of substantial elements of the accelerator. Due to the large amount of hardwired and software interlock channels the dependability of the system is a critical parameter for the successful operation of the LHC.

Application of diamond based beam loss monitors at LHC

International Nuclear Information System (INIS)

Hempel, Maria

2013-04-01

The Large Hadron Collider (LHC) was conceived in the 1980s and started the operation in 2008. It needed more than 20 years to plan and construct this accelerator and its experiments. Four main experiments are located around the ring, Compact Muon Solenoid (CMS), A Toroidal LHC Apparatus(ATLAS), A Large Ion Collider Experiment (ALICE) and LHC beauty (LHCb). Two beams that traveling in opposite direction in the LHC tunnel, collide in each of the experiments to study the questions: ''What is mass?'', ''What is the universe made of?'' and ''Why is there no antimatter?''. The four experiments take data of the collision products and try to answer the fundamental questions of physics. The two larger detectors, CMS and ATLAS, are looking for the Higgs boson to study the electroweak symmetry breaking. Both detectors were built with contrasting concepts to exclude potential error sources and to rea rm the results. The smaller experiment LHCb studies the matter-antimatter asymmetry with a focus of the beauty quark. Another smaller experiment is ALICE that studies the conditions right after the Big Bang by colliding heavy ions. The navigation of the beams is done by over 10000 magnets and each beam has a stored energy of 362MJ which correspond to the kinetic energy of a train like the TGV travelling of 150 km/h. Only a small percentage of that energy can damage the material in the LHC ring or the magnets. This would mean a repair time of months or years, without taking any data. To avoid such a scenario, it is important to monitor the beam condition and measure the amount of losses of the beam. Such losses can for example happen due to dust particles in the vacuum chambers or due to deviations of the beam parameters. Several systems called beam loss monitors (BLMs) can measure beam losses. This thesis concentrates on two of them, ionization chambers and diamond detectors. Over 3600 ionization chambers are installed in the LHC, especially near each quadrupole and next to

High Precision Current Control for the LHC Main Power Converters

CERN Document Server

Thiesen, H; Hudson, G; King, Q; Montabonnet, V; Nisbet, D; Page, S

2010-01-01

Since restarting at the end of 2009, the LHC has reached a new energy record in March 2010 with the two 3.5 TeV beams. To achieve the performance required for the good functioning of the accelerator, the currents in the main circuits (Main Bends and Main Quadrupoles) must be controlled with a higher precision than ever previously requested for a particle accelerator at CERN: a few parts per million (ppm) of nominal current. This paper describes the different challenges that were overcome to achieve the required precision for the current control of the main circuits. Precision tests performed during the hardware commissioning of the LHC illustrate this paper.

Chamonix 2016: setting the future course for the LHC and the accelerator complex

CERN Multimedia

Mike Lamont

2016-01-01

The LHC Performance Workshop took place in Chamonix between Tuesday, 25 and Thursday, 28 January. The programme included a review of the machine’s performance in 2015, a forward look at Run 2, and discussion of the status of the LHC injectors upgrade (LIU) and HL-LHC projects. The final session was dedicated to the 2019-2020 long shutdown (LS2).   The 2016 LHC Performance Workshop participants. Last year was the first year of operations following the major maintenance work of the 2013 – 2014 long shutdown (LS1). It was a tough but ultimately successful year. An analysis of operations and efficiency was performed with the aim of identifying possible improvements for 2016. The performance of key systems – e.g. machine protection, collimation, RF, transverse damper, magnetic circuits and beam diagnostics – has been good but nonetheless efforts are still being made to provide, for example, better reliability, improved functionality and monitoring. A number of c...

The LHC on an envelope

CERN Multimedia

2007-01-01

The series of envelopes featuring CERN issued this summer was a huge success. The French postal services of the Pays de Gex will shortly be launching the second set of pre-paid envelopes issued in collaboration with the Laboratory this year, this time highlighting the LHC. Five thousand envelopes describing the accelerator’s capabilities will go on sale on 12 November, and some of the packs will even contain a small sample of the cables from the heart of the LHC magnets. The sets of ten pre-paid envelopes will tell you everything about CERN’s flagship accelerator, from its astounding technical capabilities to its spin-offs in the fields of technology and human resources. Each envelope will feature a different attribute or spin-off of the LHC. People will be invited to consult CERN’s public website for more detailed explanations if they want to know more. The new envelopes will be available from five post offices in the Pays ...

LHC gets the ball rolling

CERN Multimedia

2007-01-01

A technique involving a small ball with a transmitter embedded inside it has been successfully tested in Sector 7-8. The ball is sent through the LHC beam pipes to check the LHC interconnections. The multidisciplinary team responsible for the RF ball project to check the interconnections. From left to right: Rhodri Jones (AB/BI), Eva Calvo (AB/BI), Francesco Bertinelli (AT/MCS), Sonia Bartolome Jimenez (TS/IC), Sylvain Weisz (TS/IC), Paul Cruikshank (AT/VAC), Willemjan Maan (AT/VAC), Alain Poncet (AT/MCS), Marek Gasior (AB/BI). During the tests the ball is inserted very carefully into the vacuum chamber.A game of ping-pong at the LHC? On 13 September a rather unusual test was carried out in Sector 7-8 of the accelerator. A ball just a bit smaller than a ping-pong ball was carefully introduced into one of the accelerator’s two vacuum pipes, where it travelled 800 metres in the space of a few mi...

Accelerators Beyond The Tevatron?

Energy Technology Data Exchange (ETDEWEB)

Lach, Joseph; /Fermilab

2010-07-01

Following the successful operation of the Fermilab superconducting accelerator three new higher energy accelerators were planned. They were the UNK in the Soviet Union, the LHC in Europe, and the SSC in the United States. All were expected to start producing physics about 1995. They did not. Why?

5 June 2013 - Sri Lankan Senior Minister of Scientific Affairs T. Vitharana signing the guest book with Director-General R. Heuer, in the LHC tunnel at Point 5 with International Relations Adviser R. Voss and in the CMS cavern with CERN Team leader A. Petrilli.

CERN Multimedia

Jean-Claude Gadmer

2013-01-01

5 June 2013 - Sri Lankan Senior Minister of Scientific Affairs T. Vitharana signing the guest book with Director-General R. Heuer, in the LHC tunnel at Point 5 with International Relations Adviser R. Voss and in the CMS cavern with CERN Team leader A. Petrilli.

31 Jannuary 2012 - Pakistan COMSATS Executive Director I. E. Qureshi visiting the LHC tunnel at Point 2 with ALICE Collaboration Spokesperson P. Giubellino and International Relations Adviser R. Voss; Exchange of gifts and signature of the guest book with CERN Director-General R. Heuer.

CERN Multimedia

Maximilien Brice

2012-01-01

31 Jannuary 2012 - Pakistan COMSATS Executive Director I. E. Qureshi visiting the LHC tunnel at Point 2 with ALICE Collaboration Spokesperson P. Giubellino and International Relations Adviser R. Voss; Exchange of gifts and signature of the guest book with CERN Director-General R. Heuer.

Literature in Focus Perspectives on LHC Physics

CERN Multimedia

2008-01-01

The CERN Library invites you to a book presentation, a Literature in Focus event. The Large Hadron Collider (LHC) will be the world’s largest, highest energy and highest intensity particle accelerator. This is a timely book with several perspectives on the hoped-for discoveries from the LHC. This book provides an overview of the techniques that will be crucial for finding new physics at the LHC, as well as perspectives on the importance and implications of the discoveries. Among the accomplished contributors to this book are leaders and visionaries in the field of particle physics beyond the Standard Model, including two Nobel Laureates (Steven Weinberg and Frank Wilczek). With its blend of popular and technical contents, the book will have wide appeal, not only to physical scientists but also to those in related fields. Perspectives on LHC Physics (World Scientific Publishing) Gordon Kane and Aaron Pierce (eds.) Tuesday 12 August, 4.30pm Council Chamber Refresh...

Stability of the Horizontal Curvature of the LHC Cryodipoles During Cold Tests

CERN Document Server

Cano, E D Fernandez; García-Pérez, J; Jeanneret, Jean Bernard; Poncet, A; Seyvet, F; Tovar-Gonzalez, A; Wildner, E; IEEE Trans. Nucl. Sci.

2006-01-01

The LHC will be composed of 1232 horizontally curved, 15 meter long, superconducting dipole magnets cooled at 1.9 K. They are supported within their vacuum vessel by three Glass Fiber Reinforced Epoxy (GFRE) support posts. Each cryodipole is individually cold tested at CERN before its installation and interconnection in the LHC 27 km circumference tunnel. As the magnet geometry under cryogenic operation is extremely important for the LHC machine aperture, a new method has been developed at CERN in order to monitor the magnet curvature change between warm and cold states. It enabled us to conclude that there is no permanent horizontal curvature change of the LHC dipole magnet between warm and cold states, although a systematic horizontal transient deformation during cool-down was detected. This deformation generates loads in the dipole supporting system; further investigation permitted us to infer this behavior to the asymmetric thermal contraction of the rigid magnet thermal shield during cool-down. Controlli...

Availability modeling approach for future circular colliders based on the LHC operation experience

CERN Document Server

AUTHOR|(CDS)2096726; Apollonio, Andrea; Gutleber, Johannes; Sollander, Peter; Penttinen, Jussi-Pekka; Virtanen, Seppo Johannes

2016-01-01

Reaching the challenging integrated luminosity production goals of a future circular hadron collider (FCC-hh) and high luminosity LHC (HL-LHC) requires a thorough understanding of today’s most powerful high energy physics research infrastructure, the LHC accelerator complex at CERN. FCC-hh, a 4 times larger collider ring aims at delivering 10–20  ab$^-$$^1$ of integrated luminosity at 7 times higher collision energy. Since the identification of the key factors that impact availability and cost is far from obvious, a dedicated activity has been launched in the frame of the future circular collider study to develop models to study possible ways to optimize accelerator availability. This paper introduces the FCC reliability and availability study, which takes a fresh new look at assessing and modeling reliability and availability of particle accelerator infrastructures. The paper presents a probabilistic approach for Monte Carlo simulation of the machine operational cycle, schedule and availability for p...

Protection of the LHC against Unsynchronised Beam Aborts

CERN Document Server

Goddard, B; Carlier, E; Uythoven, J; Wenninger, J; Weterings, W

2006-01-01

An unsynchronised beam abort in the LHC could damage downstream accelerator components, in particular the extraction septum magnets, the experimental low-beta triplet magnet apertures and the tertiary collimators. Although the LHC beam dumping system includes design features to minimise their frequency, such unsynchronised aborts cannot be excluded. A system of protection devices comprising fixed and moveable diluters and collimators will protect the downstream LHC aperture from the misdirected bunches in case of such a failure. The sources of unsynchronised aborts are described, together with the requirements and design of the protection devices and their expected performance. The accompanying operational requirements and envisaged solutions are discussed, in particular the problem of ensuring the local orbit at the protection devices.

Accelerators and storage rings. TS Workshop 2005. Book of Abstracts

International Nuclear Information System (INIS)

Ciriani, P.; Magnin, B.; Oliveira, R. de; Chevalley, J.; Artoos, K.; Bertone, C.; Minginette, P.; Corso, J.P.; Grillot, S.; Weisz, S.; Prodon, S.; Sakkinen, J.; Foraz, K.; Funken, A.; Bangert, N.; Hakulinen, T.; Boncompagni, Y.; Delamare, C.; Folch, R.; Poehler, M.; Bertarelli, A.; Martel, C.; Butin, F.; Osborne, J.; Evrard, S.; Lacarrere, D.; Gayde, J.C.; Renaglia, T.; Batz, M.; Tsesmelis, E.; Wijnands, T.; Perrot, A.L.; Gastal, M.; Atieh, S.; Cherif, A.; Costa Pinto, P.; Calatroni, S.; Ninin, P.; Battistin, M.; Arnau Izquierdo, G.; Favre, G.; Mathot, S.; Mainaud, H.; Podevin, C.; Jones, M.; Stowisek, J.; Roy, S.; Sanchez-Corral, E.; Petit, S.; Martel, P.; Colloca, C.; Van Der Bij, E.; Vadon, M.; Kahle, K.; Principe, R.; Macina, D.; Schmidt, R.; Ridewood, J.; Lopez-Hernandez, L.A.

2005-01-01

This document gathers the abstracts of the papers presented at the workshop. This workshop was dedicated to the status of the technical support of the LHC (large hadron collider) in CERN. The different issues concern: -) the installation of the equipment in the LHC tunnel (super-conducting magnets, cold boxes, PS magnets...), -) underground logistics, -) the installation of experimental areas, -) the new CERN control center, and -) special technologies. (A.C.)

Accelerators and storage rings. TS Workshop 2005. Book of Abstracts

Energy Technology Data Exchange (ETDEWEB)

Ciriani, P.; Magnin, B.; Oliveira, R. de; Chevalley, J.; Artoos, K.; Bertone, C.; Minginette, P.; Corso, J.P.; Grillot, S.; Weisz, S.; Prodon, S.; Sakkinen, J.; Foraz, K.; Funken, A.; Bangert, N.; Hakulinen, T.; Boncompagni, Y.; Delamare, C.; Folch, R.; Poehler, M.; Bertarelli, A.; Martel, C.; Butin, F.; Osborne, J.; Evrard, S.; Lacarrere, D.; Gayde, J.C.; Renaglia, T.; Batz, M.; Tsesmelis, E.; Wijnands, T.; Perrot, A.L.; Gastal, M.; Atieh, S.; Cherif, A.; Costa Pinto, P.; Calatroni, S.; Ninin, P.; Battistin, M.; Arnau Izquierdo, G.; Favre, G.; Mathot, S.; Mainaud, H.; Podevin, C.; Jones, M.; Stowisek, J.; Roy, S.; Sanchez-Corral, E.; Petit, S.; Martel, P.; Colloca, C.; Van Der Bij, E.; Vadon, M.; Kahle, K.; Principe, R.; Macina, D.; Schmidt, R.; Ridewood, J.; Lopez-Hernandez, L.A

2005-07-01

This document gathers the abstracts of the papers presented at the workshop. This workshop was dedicated to the status of the technical support of the LHC (large hadron collider) in CERN. The different issues concern: -) the installation of the equipment in the LHC tunnel (super-conducting magnets, cold boxes, PS magnets...), -) underground logistics, -) the installation of experimental areas, -) the new CERN control center, and -) special technologies. (A.C.)

Transport and handling LHC components A permanent challenge

CERN Document Server

Bertone, C

2004-01-01

The LHC project, collider and experiments, is an assembly of thousands of elements, large or small, heavy or light, fragile or robust. Each element has its own transport requirements that constitute a real challenge to handle. Even simple manoeuvres could lead to difficulties in integration, routing and execution due to the complex environment and confined underground spaces. Examples of typical LHC elements transport and handling will be detailed such as the 16-m long, 34-t heavy, fragile cryomagnets from the surface to the final destination in the tunnel, or the delicate cryogenic cold-boxes down to pits and detector components. This challenge did not only require a lot of imagination but also a close cooperation between all the involved parties, in particular with colleagues from safety, cryogenics, civil engineering, integration and logistics.

Fermilab "Dumbfounded" by fiasco that broke magnet

CERN Multimedia

2007-01-01

"In what is being described as a "pratfall on the world stage", the quadrupole magnet that Fermilab built for the Large Hadron Collider (LHC) particle accelerator failed high-pressure testing dramatically last week, resulting in a loud "bang" and a cloud of dust in the LHC tunnel." (1,5 page)

Design study of the large hadron electron collider and a rapid cycling synchrotron as alternative to the PS booster upgrade at CERN

International Nuclear Information System (INIS)

Fitterer, Miriam

2013-01-01

With the Large Hadron Collider (LHC) the exploration of particle physics at center of mass energies at the TeV scale has begun. To extend the discovery potential of the LHC, a major upgrade is foreseen around 2020 of the LHC itself and the LHC injectors - the chain of accelerators preparing the beam for the LHC. One of the injectors - the second one in the chain - is the Proton Synchrotron (PS) Booster. Its performance is currently limited by the space-charge effect, which is the effect of the electromagnetic field of the particle beam on itself. This effect becomes weaker with higher energy, and therefore an energy upgrade of the PS Booster to 2 GeV maximum beam energy is foreseen. As the PS Booster is with its 40 years already an old machine, the construction of a new accelerator, a Rapid Cycling Synchrotron (RCS), to replace the PS Booster has been proposed. In this thesis different options for the beam guidance in the RCS - referred to as lattice and optics - are studied, followed by a more general comparison of different lattices and optics and their performance under consideration of the space-charge effect. To further complement the LHC physics program, also the possibility of deep inelastic lepton-nucleon scattering at the LHC has been suggested, referred to as Large Hadron Electron Collider (LHeC). In this case the proton beam of the LHC collides with the electron beam, which is accelerated in a separate newly built machine. Two options are considered as electron accelerator: a new energy recovery linac - the Linac-Ring option - and the installation of an electron ring in the existing LHC tunnel - the Ring-Ring option. One of the main challenges of the Ring-Ring option is the integration of the electron ring in the current LHC tunnel. A layout, lattice and optics of the electron accelerator is developed in this thesis, which meets the requirements with regard to integration and reaches the beam parameters demanded by the particle physics experiments.

Design study of the large hadron electron collider and a rapid cycling synchrotron as alternative to the PS booster upgrade at CERN

Energy Technology Data Exchange (ETDEWEB)

Fitterer, Miriam

2013-02-22

With the Large Hadron Collider (LHC) the exploration of particle physics at center of mass energies at the TeV scale has begun. To extend the discovery potential of the LHC, a major upgrade is foreseen around 2020 of the LHC itself and the LHC injectors - the chain of accelerators preparing the beam for the LHC. One of the injectors - the second one in the chain - is the Proton Synchrotron (PS) Booster. Its performance is currently limited by the space-charge effect, which is the effect of the electromagnetic field of the particle beam on itself. This effect becomes weaker with higher energy, and therefore an energy upgrade of the PS Booster to 2 GeV maximum beam energy is foreseen. As the PS Booster is with its 40 years already an old machine, the construction of a new accelerator, a Rapid Cycling Synchrotron (RCS), to replace the PS Booster has been proposed. In this thesis different options for the beam guidance in the RCS - referred to as lattice and optics - are studied, followed by a more general comparison of different lattices and optics and their performance under consideration of the space-charge effect. To further complement the LHC physics program, also the possibility of deep inelastic lepton-nucleon scattering at the LHC has been suggested, referred to as Large Hadron Electron Collider (LHeC). In this case the proton beam of the LHC collides with the electron beam, which is accelerated in a separate newly built machine. Two options are considered as electron accelerator: a new energy recovery linac - the Linac-Ring option - and the installation of an electron ring in the existing LHC tunnel - the Ring-Ring option. One of the main challenges of the Ring-Ring option is the integration of the electron ring in the current LHC tunnel. A layout, lattice and optics of the electron accelerator is developed in this thesis, which meets the requirements with regard to integration and reaches the beam parameters demanded by the particle physics experiments.

Rejuvenating CERN's Accelerators

CERN Multimedia

2004-01-01

In the coming years and especially in 2005, CERN's accelerators are going to receive an extensive renovation programme to ensure they will perform reliably and effectively when the LHC comes into service.

The Interconnections of the LHC Cryomagnets

CERN Document Server

Jacquemod, A; Skoczen, Blazej; Tock, J P

2001-01-01

The main components of the LHC, the next world-class facility in high-energy physics, are the twin-aperture high-field superconducting cryomagnets to be installed in the existing 26.7-km long tunnel. After installation and alignment, the cryomagnets have to be interconnected. The interconnections must ensure the continuity of several functions: vacuum enclosures, beam pipe image currents (RF contacts), cryogenic circuits, electrical power supply, and thermal insulation. In the machine, about 1700 interconnections between cryomagnets are necessary. The interconnections constitute a unique system that is nearly entirely assembled in the tunnel. For each of them, various operations must be done: TIG welding of cryogenic channels (~ 50 000 welds), induction soldering of main superconducting cables (~ 10 000 joints), ultrasonic welding of auxiliary superconducting cables (~ 20 000 welds), mechanical assembly of various elements, and installation of the multi-layer insulation (~ 200 000 m2). Defective junctions cou...

19 January 2011 - Korean Vice Minister II of Education, Science and Technology K.Chang-Kyung with Adviser R. Voss, Director-General R. Heuer and head of International Relations F. Pauss; in the LHC tunnel at Point 5 and CMS experimental cavern with Collaboration Spokesperson G. Tonelli.

CERN Multimedia

Maximilien Brice

2011-01-01

Korean vice-minister II of education, science and technology, Kim Chang-Kyung, visiting the CMS experimental area at CERN on 19 January. He also had the opportunity to view part of the LHC tunnel, as well as to visit the CERN Control Centre.

Non-simplified SUSY. τ-coannihilation at LHC and ILC

Energy Technology Data Exchange (ETDEWEB)

Berggren, M.; Kruecker, D.; List, J.; Melzer-Pellmann, I.A.; Seitz, C. [DESY, Hamburg (Germany); Cakir, A. [DESY, Hamburg (Germany); Istanbul Technical University, Department of Physics Engineering, Istanbul (Turkey); Samani, B.S. [DESY, Hamburg (Germany); IPM, P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Wayand, S. [KIT IEKP, Karlsruhe (Germany)

2016-04-15

If new phenomena beyond the Standard Model will be discovered at the LHC, the properties of the new particles could be determined with data from the High-Luminosity LHC and from a future linear collider like the ILC. We discuss the possible interplay between measurements at the two accelerators in a concrete example, namely a full SUSY model which features a small τ-LSP mass difference. Various channels have been studied using the Snowmass 2013 combined LHC detector implementation in the Delphes simulation package, as well as simulations of the ILD detector concept from the Technical Design Report. We investigate both the LHC and the ILC capabilities for discovery, separation and identification of various parts of the spectrum. While some parts would be discovered at the LHC, there is substantial room for further discoveries at the ILC. We finally highlight examples where the precise knowledge about the lower part of the mass spectrum which could be acquired at the ILC would enable a more in-depth analysis of the LHC data with respect to the heavier states. (orig.)

CERN confident of LHC start-up in 2007

CERN Document Server

2007-01-01

"Delegates attending the 140th meeting of CERN Council heard a confident report from the Laboratory about the scheduled start-up of the world's highest energy particle accelerator, the Large Hadron Collier (LHC), in 2007." (1 page)

The latest from the LHC

CERN Multimedia

2009-01-01

View of the LHC tunnel after the repairs.Three weeks ago vacuum leaks occurred in both Sector 8-1 and 2-3 (See previous update). While the cause and exact locations of the leaks are still unknown, it is suspected that they occurred in both cases from a flexible hose in the liquid helium transport circuits, which vented helium into the vacuum insulation. In Sector 8-1 the leaks occurred while it was being maintained at 80 K in order to perform the resistance measurements on the copper part of the superconducting busbars. Less than 24 hours later a similar leak occurred in Sector 2-3 while it was being warmed from superconducting temperatures to 80 K to perform the busbar resistance measurement. Both leaks happened where the final magnet of the sector (known as Q7) joins the electrical feedbox (called the DFBA). The end vacuum subsectors – a 200-metre stretch of the LHC sealed off by vacuum barriers – will be warmed to room temp...

Ten out of ten for LHC decapole magnets

CERN Multimedia

2001-01-01

CERN's Albert Ijspeert (left) and Avinash Puntambekar of the Indian CAT laboratory with the ten Indian decapole magnets on the test bench. Tests will be carried out by the LHC-MTA group. A batch of 10 superconducting decapole magnets for the LHC has just arrived at CERN from India. These will be used to correct for slight imperfections in the dipole magnets that will steer proton beams around CERN's new accelerator. All magnets have slight imperfections in the fields they produce, and in the LHC dipoles these will be corrected for using sextupoles and decapoles. The sextupoles were the first LHC magnets to be given the production green-light following successful tests of pre-series magnets last year (Bulletin 21/2000, 22 May 2000). Now it is the turn of pre-series decapoles to go on trial at CERN. Of the LHC's 1232 dipole magnets, half will use sextupole correctors only and the other half will use both sextupoles and decapoles. That means that a total of 616 pairs of decapoles are needed. Like the sextupole...

5th report from the LHC performance workshop

CERN Multimedia

Bulletin's correspondent from Chamonix

2012-01-01

The morning session on Friday 10 February - the final day of the workshop - saw further examination of the challenges of the High Luminosity LHC and included a look at the state of R&D for the new magnets required for the high luminosity interaction regions. There was then an entertaining look at even more distant future. Possible future projects under consideration include the Large Hadron electron Collider (LHeC) which foresees colliding 60 GeV electrons with 7 TeV protons, and the High Energy LHC (HE-LHC) in which the beam energy of the LHC is increased from 7 to 16.5 TeV. Serious technological challenges exist for both these options. In the afternoon Steve Myers, CERN's Director for Accelerators and Technology, presented a summary of the workshop recommendations. In brief, the LHC should operate at 4 TeV in 2012 with the key priorities being: delivering enough luminosity to ATLAS and CMS to allow them to independently discover or exclude the Higgs; the proton-Lead ion run; and machine deve...

Protection against Accidental Beam Losses at the LHC

CERN Document Server

Wenninger, Jörg

2005-01-01

Protection of the LHC against uncontrolled beam losses is of prime importance due to the very high stored beam energy. For nominal beam intensities, each of the two 7 TeV/c proton beams has a stored energy of 360 MJ threatening to damage accelerator equipment. At injection a number of passive beam absorbers must be correctly positioned and specific procedures have been proposed to ensure safe injection of high intensity. The LHC beam dump block being the only LHC element that can safety absorb the full LHC beam, it is essential that the beams are extracted unto the dump block in case of emergency. The failure time constants extend from 100 microseconds to few seconds depending on the equipment. Failures must be detected at a sufficiently early stage and transmitted to the beam interlock system that triggers the beam dumping system. To ensure safe operation the machine protection system uses a variety of systems to detect such failures. The strategy for protection of the LHC will be illustrated, with emphasis ...

LEP superconducting accelerating cavity module

CERN Multimedia

1995-01-01

With its 27-kilometre circumference, the Large Electron-Positron (LEP) collider was the largest electron-positron accelerator ever built. The excavation of the LEP tunnel was Europe’s largest civil-engineering project prior to the Channel Tunnel. Three tunnel-boring machines started excavating the tunnel in February 1985 and the ring was completed three years later. In its first phase of operation, LEP consisted of 5176 magnets and 128 accelerating cavities. CERN’s accelerator complex provided the particles and four enormous detectors, ALEPH, DELPHI, L3 and OPAL, observed the collisions. LEP was commissioned in July 1989 and the first beam circulated in the collider on 14 July. The collider's initial energy was chosen to be around 91 GeV, so that Z bosons could be produced. The Z boson and its charged partner the W boson, both discovered at CERN in 1983, are responsible for the weak force, which drives the Sun, for example. Observing the creation and decay of the short-lived Z boson was a critical test of...

Restart of the LHC. New physics. The particle physics behind the world machine illustratively explained; Neustart des LHC. Neue Physik. Die Teilchenphysik hinter der Weltmaschine anschaulich erklaert

Energy Technology Data Exchange (ETDEWEB)

Knochel, Alexander

2016-07-01

The following topics are dealt with: The ascertainment of scientific virgin territory by means of the LHC ar CERN, the study of actual questions of cosmology and astrophysics like dark matter and dark energy by means of the LHC, the presently existing anomalies in the data with regards to new phenomena together with statistical methods for the correct estimation of such observations, the supplement of other experiments for the LHC experiments, the Higgs boson, supersymmetry, higher dimensions, the study of quantum gravity in accelerator experiments with regards to the string theory. (HSI)

CERN confident of LHC start-up in 2007

CERN Document Server

Vanden Broeck, Renilde

2007-01-01

"Delegates attending the 140th meeting of CERN Council today heard a confident report from the Laboratory about the scheduled start-up of the world's highest energy particle accelerator, the Large Hadron Collier (LHC) in 2007. (1/2 page)

CERN confident of LHC start-up in 2007

CERN Multimedia

2006-01-01

"Delegates attending the 140th meeting of CERN Council today heard a confident report from the Laboratory about the scheduled start-up of the world's highest energy particle accelerator, the Large Hadron Collider (LHC) in 2007." (1/2 page)

Status of superconducting magnet development (SSC, RHIC, LHC)

International Nuclear Information System (INIS)

Wanderer, P.

1993-01-01

This paper summarizes recent superconducting accelerator magnet construction and test activities at the Superconducting Super Collider Laboratory (SSC), the Large Hardon Collider at CERN (LHC), and the Relativistic Heavy Ion Collider at Brookhaven (RHIC). Future plans are also presented

Status of superconducting magnet development (SSC, RHIC, LHC)

International Nuclear Information System (INIS)

Wanderer, P.

1993-01-01

This paper summarize recent superconducting accelerator magnet construction and test activities at the Superconducting Super Collider Laboratory (SSC), the Large Hadron Collider at CERN (LHC), and the Relativistic Heavy Ion Collider at Brookhaven (RHIC). Future plan are also presented

Successful beam test of the SPS-to-LHC transfer line TI2

CERN Multimedia

2007-01-01

Image of the first beam spot on the last BTV screen traversed by the beam during the TI 2 test.At 12:03:47 on 28 October a beam passed down the 2.7 km of the new SPS-to-LHC transfer line TI 2 at the first attempt, to within some 50 m of the LHC tunnel. After initial tuning, a range of measurements was carried out with a low intensity proton beam and preliminary analyses look good. After the test, no increase in radiation levels was found in either the LHC or ALICE, and the zones were rapidly opened again for access. As from next year TI 2 will regularly transport a beam from the SPS to the LHC injection point of Ring 1, near Point 2 (ALICE). The TI 8 transfer line, which will bring particles from the SPS to the injection point in Ring 2, near Point 8 (LHCb), was commissioned successfully with low intensity beam in 2004. The two LHC injection lines have a combined length of 5.6 km and comprise some seven hundred warm magnets. While a...

Application of diamond based beam loss monitors at LHC

Energy Technology Data Exchange (ETDEWEB)

Hempel, Maria

2013-04-15

The Large Hadron Collider (LHC) was conceived in the 1980s and started the operation in 2008. It needed more than 20 years to plan and construct this accelerator and its experiments. Four main experiments are located around the ring, Compact Muon Solenoid (CMS), A Toroidal LHC Apparatus(ATLAS), A Large Ion Collider Experiment (ALICE) and LHC beauty (LHCb). Two beams that traveling in opposite direction in the LHC tunnel, collide in each of the experiments to study the questions: ''What is mass?'', ''What is the universe made of?'' and ''Why is there no antimatter?''. The four experiments take data of the collision products and try to answer the fundamental questions of physics. The two larger detectors, CMS and ATLAS, are looking for the Higgs boson to study the electroweak symmetry breaking. Both detectors were built with contrasting concepts to exclude potential error sources and to rea rm the results. The smaller experiment LHCb studies the matter-antimatter asymmetry with a focus of the beauty quark. Another smaller experiment is ALICE that studies the conditions right after the Big Bang by colliding heavy ions. The navigation of the beams is done by over 10000 magnets and each beam has a stored energy of 362MJ which correspond to the kinetic energy of a train like the TGV travelling of 150 km/h. Only a small percentage of that energy can damage the material in the LHC ring or the magnets. This would mean a repair time of months or years, without taking any data. To avoid such a scenario, it is important to monitor the beam condition and measure the amount of losses of the beam. Such losses can for example happen due to dust particles in the vacuum chambers or due to deviations of the beam parameters. Several systems called beam loss monitors (BLMs) can measure beam losses. This thesis concentrates on two of them, ionization chambers and diamond detectors. Over 3600 ionization chambers are installed in

The Commissioning of the LHC Technical Systems

CERN Document Server

Saban, R; Baggiolini, V; Ballarino, A; Barbero-Soto, E; Bellesia, B; Bordry, Frederick; Bozzini, D; Casas-Lino, M-P; Chareyre, V; Claudet, S; Coelingh, G-J; Dahlerup-Petersen, K; Denz, R; Fehér, S; Flora, R; Gruwé, M; Kain, V; Kirby, G; Koratzinos, M; Lauckner, R; Le Naour, S; Mess, K-H; Millet, F; Montabonnet, V; Nisbet, D; Perea-Solano, B; Pojer, M; Principe, R; Rabehl, R; Rijllart, A; Redaelli, S; Rodríguez-Mateos, F; Schmidt, R; Serio, L; Siemko, A; Solfaroli-Camillocci, M; Thiesen, H; Venturini, W; Vergara-Fernandez, A; Verweij, A; Zerlauth, M

2007-01-01

The LHC is an accelerator with unprecedented complexity where the energy stored in magnets and the beams exceeds other accelerators by one-to-two orders of magnitude. To ensure a safe and efficient machine start-up without being plagued by technical problems, a phase of "hardware commissioning" was introduced: a thorough commissioning of technical systems without beam. This activity started in June 2005 with the commissioning of individual systems, followed by operating a full sector, one eighth of the machine; the commissioning is expected to last until spring 2008 when commissioning with beam will start. The LHC architecture allows the commissioning of each of the eight sectors independently from the others, before the installation of other sectors is complete. An important effort went into the definition of the programme and the organization of the coordination in the field, as well as in the preparation of the tools to record and analyze test results. This paper discusses the experience with this approach...

14 February 2012 - Ambassadors from Algeria, Brunei Darussalam, Canada, Chad, Tunisia, Permanent Representatives to the United Nations Office at Geneva in the LHC tunnel at Point 1, ATLAS visitor centre, and ATLAS underground experimental area, throughout accompanied by Advisers P. Fassnacht, E. Tsesmelis and R. Voss

CERN Multimedia

Jean-Claude Gadmer

2012-01-01

14 February 2012 - Ambassadors from Algeria, Brunei Darussalam, Canada, Chad, Tunisia, Permanent Representatives to the United Nations Office at Geneva in the LHC tunnel at Point 1, ATLAS visitor centre, and ATLAS underground experimental area, throughout accompanied by Advisers P. Fassnacht, E. Tsesmelis and R. Voss

1 October 2013 - British Minister of State for Trade and Investment Lord Green of Hurstpierpoint signing the guest book with Head of Internationals Relations R. Voss; visiting the LHC tunnel at Point 1 and the ATLAS experimental cavern with ATLAS Collaboration Members K. Behr and J. Catmore.

CERN Multimedia

Jean-Claude Gadmer

2013-01-01

1 October 2013 - British Minister of State for Trade and Investment Lord Green of Hurstpierpoint signing the guest book with Head of Internationals Relations R. Voss; visiting the LHC tunnel at Point 1 and the ATLAS experimental cavern with ATLAS Collaboration Members K. Behr and J. Catmore.

“Shape memory” material provides a solution for the HL-LHC

CERN Multimedia

Anaïs Schaeffer & Stefania Pandolfi

2016-01-01

A collaboration between CERN and the University of Calabria is developing a new connection device for vacuum chambers based on Shape Memory Alloy (SMA) rings, for future use in the High-Luminosity LHC (HL-LHC). The unique characteristics of these materials, able to memorise different shapes at high and low temperatures, are being exploited to create a high-tech solution for sealing the vacuum chambers of the upgraded accelerator.   Proof of concept of a SMA connector for Ultra High Vacuum (UHV) chambers. (Picture: Fabrizio Niccoli) In particle accelerators, beams circulate inside vacuum chambers connected by flanges - complex engineering components which ensure the integrity of the vacuum system. Currently, there are two types of flanges used in the LHC: standard “ConFlat” flanges, which are bolted together; and the quick conical connection flanges used on radioactive components (for example collimators), which need large and heavy chain clamps. Clamping or unclamping...

Measurements of very forward particles production spectra at LHC: the LHCf experiment

CERN Document Server

Berti, Eugenio; Bonechi, Lorenzo; Bongi, Massimo; Castellini, Guido; D'Alessandro, Raffaello; Haguenauer, Maurice; Itow, Yoshitaka; Iwata, Taiki; Kasahara, Katsuaki; Makino, Yuya; Masuda, Kimiaki; Matsubayashi, Eri; Menjo, Hiroaki; Muraki, Yasushi; Papini, Paolo; Ricciarini, Sergio; Sako, Takashi; Suzuki, Takuya; Tamura, Tadahisa; Tiberio, Alessio; Torii, Shoji; Tricomi, Alessia; Turner, W C; Ueno, Mana; Zhou, Qi Dong

2017-01-01

Thanks to two small sampling calorimeters installed in the LHC tunnel at ±140 m from IP1, the LHC forward (LHCf) experiment is able to detect neutral particles produced by high energy proton-ion collisions in the very forward region (pseudo-rapidity η > 8.4). The main aim of LHCf is to provide precise measurements of the production spectra relative to these particles, in order to tune hadronic interaction models used by ground-based cosmic rays experiments. In this paper we will present the current status of the LHCf experiment, regarding in particular collected data and analysis results, as well as future prospects

11 June 2013- Autrian Federal President Dr Heinz Fischer and Federal Minister Prof. Dr Karlheinz Töchterle visit CMS cavern and LHC tunnel at Point 5 and the ASACUSA and AEGIS experiments on the AD. Signature of the guest book in the Globe of Science and Innovation after a round table with 10 young austrian scientists. Family photograph in front of an LHC magnet.

CERN Multimedia

TEAM VMO

2013-01-01

Welcome line: on French territory by the Representative of the French Republic S. Donnot, Sous-Préfet de Gex; CERN Director-General R. Heuer; Director for Research and Scientific Computing S. Bertolucci; Director for Accelerators and Technology S. Myers; Director for Administration and general Infrastructure S. Lettow; Head of Technology Department F. Bordry; CERN Austrian Circle Spokesperson F. Eder and CERN Protocol S. Molinari. First Lady and Federal Minister Töchterle follow. CERN-HI-1306154 19-32: in CMS conference room, building 3562: general presentation of the Laboratory by the DG; CERN-HI-1306154 33-43: visiting the LHC tunnel at Point 5 with Head of Technology Department F. Bordry CERN-HI-1306154 44-64: in the CMS cavern with Collaboration Spokesperson J. Incandela and CMS and Austrian Academy of Sciences C. Wulz; CERN-HI-1306154 65-90: ASACUSA with E. Widmann and AEGIS with M. Doser. CERN-HI-1306154 91-115: round table, signatures and exchange of gifts in the Globe of Science and Innovation; fa...

The LHC in an envelope

CERN Multimedia

2007-01-01

The series of envelopes featuring CERN issued this summer was a huge success. The French postal services of the Pays de Gex will shortly be launching the second set of pre-paid envelopes issued in collaboration with the Laboratory this year, this time highlighting the LHC. Five thousand envelopes describing the accelerator’s capabilities will go on sale on 12 November, and some of the packs will even contain a small sample of the cables from the heart of the LHC magnets. The sets of ten pre-paid envelopes will tell you everything about CERN’s flagship accelerator, from its astounding technical capabilities to its spin-offs in the fields of technology and human resources. Each envelope will feature a different attribute or spin-off of the LHC. People will be invited to consult CERN’s public website for more detailed explanations if they want to know more. The new envelopes will be available from five post offices in the Pays de Gex (Ferney-Voltaire, Prévessin...

The LHC cryogenic operation for first collisions and physics run

CERN Document Server

Brodzinski, K; Benda, V; Bremer, J; Casas-Cubillos, J; Claudet, S; Delikaris, D; Ferlin, G; Fernandez Penacoba, G; Perin, A; Pirotte, O; Soubiran, M; Tavian, L; van Weelderen, R; Wagner, U

2011-01-01

The Large Hadron Collider (LHC) cryogenic system was progressively and successfully run for the LHC accelerator operation period starting from autumn 2009. The paper recalls the cryogenic system architecture and main operation principles. The system stability during magnets powering and availability periods for high energy beams with first collisions at 3.5 TeV are presented. Treatment of typical problems, weak points of the system and foreseen future consolidations will be discussed.

Big Bang test delayed at CERN's LHC until 2008

CERN Multimedia

Atkins, William

2007-01-01

"Scientists at the proton-proton Large Hadron Collider (LHC) particle accelerator and collider will postpone a test that could help solve the mystery of what happened a few nanoseconds after the Big Bang." (1 page)

Machine Protection: Availability for Particle Accelerators

CERN Document Server

Apollonio, Andrea; Schmidt, Ruediger

2015-03-16

Machine availability is a key indicator for the performance of the next generation of particle accelerators. Availability requirements need to be carefully considered during the design phase to achieve challenging objectives in different fields, as e.g. particle physics and material science. For existing and future High-Power facilities, such as ESS (European Spallation Source) and HL-LHC (High-Luminosity LHC), operation with unprecedented beam power requires highly dependable Machine Protection Systems (MPS) to avoid any damage-induced downtime. Due to the high complexity of accelerator systems, finding the optimal balance between equipment safety and accelerator availability is challenging. The MPS architecture, as well as the choice of electronic components, have a large influence on the achievable level of availability. In this thesis novel methods to address the availability of accelerators and their protection systems are presented. Examples of studies related to dependable MPS architectures are given i...

Deployment and Integration of Industrial Controls The Case of LHC Cryogenics Controls

CERN Document Server

Gayet, P

2003-01-01

The new cryogenics controls for LHC (UNICOS) are implemented in an open architecture based on SCADA and PLC industrial components, with Ethernet as Fieldnetwork. Its development was outsourced to industry and since mid-2001 several applications have been produced and delivered for refrigerators in the accelerator and experiment domains. This has allowed to validatedetailed performance requirements in terms of communication and distributed architecture. The second phase of this project will involve its integration with the LHC accelerator controls, both at the information exchange level (alarms, data logging) and at the device configuration level. This phase takes advantage of the integrated design at PLC and SCADA level, leading to the use of configuration tools which can be easily connected to the generic device configuration model of the accelerator controls.

LHC Operation: Past and Future (1/3)

CERN Multimedia

CERN. Geneva

2013-01-01

After a successful first running period, LHC is now well into a two year shutdown for extensive consolidation. A pedagogical overview of the machine, its operating principles, its systems and underlying accelerator physics is presented. Performance past and future is discussed. (These lectures will be presented in three parts.)

Measurements at LHC and their relevance for cosmic ray physics

CERN Multimedia

CERN. Geneva

2016-01-01

Many LHC measurements are already used to improve hadronic interaction models used in cosmic ray analyses. This already had a positive effect on the model dependence of crucial data analyses. Some of the data and the model tuning is reviewed. However, the LHC still has a lot more potential to provide crucial information. Since the start of Run2 the highest accelerator beam energies are reached and no further increase can be expected for a long time. First data of Run2 are published and the fundamental performance of cosmic ray hadronic interaction models can be scrutinized. The relevance of LHC data in general for cosmic ray data analyses is demonstrated.

Commissioning the cryogenic system of the first LHC sector

International Nuclear Information System (INIS)

Millet, F.; Claudet, S.; Ferlin, G.; Perin, A.; Riddone, G.; Serio, L.; Soubiran, M.; Tavian, L.; CERN; Ronayette, L.; GHMFL, Grenoble; Rabehl, R.; Fermilab

2007-01-01

The LHC machine, composed of eight sectors with superconducting magnets and accelerating cavities, requires a complex cryogenic system providing high cooling capacities (18 kW equivalent at 4.5 K and 2.4 W at 1.8 K per sector produced in large cold boxes and distributed via 3.3-km cryogenic transfer lines). After individual reception tests of the cryogenic subsystems (cryogen storages, refrigerators, cryogenic transfer lines and distribution boxes) performed since 2000, the commissioning of the cryogenic system of the first LHC sector has been under way since November 2006. After a brief introduction to the LHC cryogenic system and its specificities, the commissioning is reported detailing the preparation phase (pressure and leak tests, circuit conditioning and flushing), the cool-down sequences including the handling of cryogenic fluids, the magnet powering phase and finally the warm-up. Preliminary conclusions on the commissioning of the first LHC sector will be drawn with the review of the critical points already solved or still pending. The last part of the paper reports on the first operational experience of the LHC cryogenic system in the perspective of the commissioning of the remaining LHC sectors and the beam injection test

Large Cryogenic Infrastructure for LHC Superconducting Magnet and Cryogenic Component Tests: Layout, Commissioning and Operational Experience

International Nuclear Information System (INIS)

Calzas, C.; Chanat, D.; Knoops, S.; Sanmarti, M.; Serio, L.

2004-01-01

The largest cryogenic test facility at CERN, located at Zone 18, is used to validate and to test all main components working at cryogenic temperature in the LHC (Large Hadron Collider) before final installation in the machine tunnel. In total about 1300 main dipoles, 400 main quadrupoles, 5 RF-modules, eight 1.8 K refrigeration units will be tested in the coming years.The test facility has been improved and upgraded over the last few years and the first 18 kW refrigerator for the LHC machine has been added to boost the cryogenic capacity for the area via a 25,000 liter liquid helium dewar. The existing 6 kW refrigerator, used for the LHC Test String experiments, will also be employed to commission LHC cryogenic components.We report on the design and layout of the test facility as well as the commissioning and the first 10,000 hours operational experience of the test facility and the 18 kW LHC refrigerator

Tunneling beyond the Fermilab site

International Nuclear Information System (INIS)

Baker, S.; Elwyn, A.; Lach, J.; Read, A.

1983-01-01

An accelerator that crosses the Fermilab site boundary must have a minimum effect on the surrounding environment and the people residing in the area. Unobstructed public access should be allowed above the ring except in relatively few areas such as the injection, dump, and experimental regions. The accelerator should be a benign and unobtrusive neighbor not only when it is completed but also in the construction period. For these reasons underground tunneling for all or most of the ring seems attractive. In this note we look into some questions raised by tunneling beyond the Fermilab site. Most of our discussion is of general applicability. However, we will use as examples two specific ring configurations. The examples have not been optimized from the point of view of physics output or accelerator technology but are just specific examples which allow us to study questions of tunneling. One is a ring of 5 km radius (5 TeV) tangent to the Tevatron and entirely east of the Fox River and fed by a beam from the Tevatron which crosses under the river. We assume that each of these machines will have 100 beam fills per year and we scale the maximum intensities with the accelerator radii. Thus we assume that there will be 1.0 E14 protons in each beam of the 20 TeV machine and 2.5 E13 for the 5 TeV machine

LHC Availability 2017: Standard Proton Physics

CERN Document Server

Todd, Benjamin; Apollonio, Andrea; Walsh, David John; CERN. Geneva. ATS Department

2017-01-01

This document summarises the LHC machine availability for the period from restart to the end of standard proton physics in 2017. This covers the whole standard proton physics production period. This note has been produced and ratified by the Availability Working Group which has complied fault information for the period in question using the Accelerator Fault Tracker.

Accelerators at school

Energy Technology Data Exchange (ETDEWEB)

Anon.

1986-06-15

Latest subject covered by the CERN Accelerator School was 'Applied Geodesy of Particle Accelerators', which attracted an impressive number of outside participants to CERN for a week in April. Since the forerunners of today's particle accelerators were demonstrated over 50 years ago, the positioning of accelerator components has progressed from the laboratory bench-top to tunnels tens of kilometres long. Despite this phenomenal growth in size, sub-millimetre accuracy is still required.

The large Hadron Collider (LHC) and the search for the divine particle

International Nuclear Information System (INIS)

Sanchez, G.

2008-01-01

The large Hadron Collider (LHC) is a particle circular accelerator of 27 km of circumference. I t will be used to study the smallest known particles. Two beams of subatomic particles called hadrons either protons or lead ion- will travel in opposite directions inside the circular accelerator gaining energy with every lap. Physicists will use the LHC to recreate the conditions just after the Big Bang, by colliding the two beams had-on at very high energy. There are many theories as to what will result from these collisions, but what's for sure is that a brave new world of physics will emerge from the new accelerator, as knowledge in particle physics goes on to describe the working of the Universe. for decades, the Standard Model of particle physics has served physicists well as a means of understanding the fundamental laws of Nature, but it does not tell the whole story. Only experimental data using the higher energies reached by the LHC can push knowledge forward, challenging those who seek confirmation of established knowledge, and those who dare to dream beyond the paradigm. The Higgs boson, that complete the standard model, is waited to be found. (Author)

From the LHC Reference Database to the Powering Interlock System

CERN Document Server

Dehavay, C; Schmidt, R; Veyrunes, E; Zerlauth, M

2003-01-01

The protection of the magnet powering system for the Large Hadron Collider (LHC) currently being built at CERN is a major challenge due to the unprecedented complexity of the accelerator. The Powering Interlock System of the LHC will have to manage more than 1600 DC circuits for magnet powering, different in their structure, complexity and importance to the accelerator. For the coherent description of such complex system, a Reference Database as unique source of the parameters of the electrical circuits has been developed. The information, introduced via a generic circuit description language, is first used for installing the accelerator and making all electrical connections. The data is then used for tests and commissioning. During operation, the Powering Interlock System manages all critical functions. It consists of 36 PLC based controllers dis tributed around the machine and requires a flexible and transparent way of configuration, since each controller manages different numbers and types of electrical ci...

Topics in the measurement of electrons with the ATLAS detector at the LHC

CERN Document Server

Thioye, Moustapha

2008-01-01

Upon completion in 2008, the Large Hadron Collider (LHC) will accelerate and collide protons with a 14~TeV center-of-mass energy at a designed luminosity of $10^{34}\\rm {cm^{-2}s^{-1}}$. The LHC will also be able to accelerate and collide heavy ions (Pb-Pb) at a nucleon-nucleon center of mass of 5.5~TeV. It will be the most powerful instrument ever built to investigate particles properties. The ATLAS (A Toroidal LHC ApparatuS) experiment is one of five experiments at the LHC. ATLAS is a general-purpose detector designed for the discovery of new particles predicted by the Standard Model (i.e Higgs boson), and of signatures of physics beyond the Standard Model (i.e supersymmetry). These discoveries require a highly efficient detection and high-resolution measurement of leptons or photons in the final state. In ATLAS, the liquid Argon (LAr) calorimeters identify and measure electrons and photons with high resolution. This dissertation reports on a study of various topics relevant to the measurement of electrons ...

High-Luminosity Large Hadron Collider (HL-LHC) Preliminary Design Report

CERN Document Server

Apollinari, G; Béjar Alonso, I; Brüning, O; Lamont, M; Rossi, L

2015-01-01

The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up a new energy frontier for exploration in 2010, it has gathered a global user community of about 7,000 scientists working in fundamental particle physics and the physics of hadronic matter at extreme temperature and density. To sustain and extend its discovery potential, the LHC will need a major upgrade in the 2020s. This will increase its luminosity (rate of collisions) by a factor of five beyond the original design value and the integrated luminosity (total collisions created) by a factor ten. The LHC is already a highly complex and exquisitely optimised machine so this upgrade must be carefully conceived and will require about ten years to implement. The new configuration, known as High Luminosity LHC (HL-LHC), will rely on a number of key innovations that push accelerator technology beyond its present limits. Among these are cutting-edge 11-12 tesla superconducting magnets, compact superconducting cav...

Accelerating News Issue 3

CERN Document Server

Kahle, K; Tanguy, C; Wildner, E

2012-01-01

This summer saw CERN announce to a worldwide audience the discovery of a Higgs-like boson, so this issue takes a look at the machine behind the discovery, the LHC, as well as future plans for a possible Higgs factory in the form of LEP3. Looking ahead too are European strategies for particle physics and accelerator-based neutrino physics. In addition, taking stock of the work so far, HiLumi LHC and EuCARD showcase their latest results.

The BRAN luminosity detectors for the LHC

Energy Technology Data Exchange (ETDEWEB)

Matis, H.S.; Placidi, M.; Ratti, A.; Turner, W.C. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Bravin, E. [CERN, 1211 Geneva 23 (Switzerland); Miyamoto, R. [European Spallation Source, ESS AB, P.O. Box 176, SE-221 00 Lund (Sweden)

2017-03-11

This paper describes the several phases which led, from the conceptual design, prototyping, construction and tests with beam, to the installation and operation of the BRAN (Beam RAte of Neutrals) relative luminosity monitors for the LHC. The detectors have been operating since 2009 to contribute, optimize and maintain the accelerator performance in the two high luminosity interaction regions (IR), the IR1 (ATLAS) and the IR5 (CMS). The devices are gas ionization chambers installed inside a neutral particle absorber 140 m away from the Interaction Points in IR1 and IR5 and monitor the energy deposited by electromagnetic showers produced by high-energy neutral particles from the collisions. The detectors have the capability to resolve the bunch-by-bunch luminosity at the 40 MHz bunch rate, as well as to survive the extreme level of radiation during the nominal LHC operation. The devices have operated since the early commissioning phase of the accelerator over a broad range of luminosities reaching 1.4×10{sup 34} cm{sup −2} s{sup −1} with a peak pileup of 45 events per bunch crossing. Even though the nominal design luminosity of the LHC has been exceeded, the BRAN is operating well. After describing how the BRAN can be used to monitor the luminosity of the collider, we discuss the technical choices that led to its construction and the different tests performed prior to the installation in two IRs of the LHC. Performance simulations are presented together with operational results obtained during p-p operations, including runs at 40 MHz bunch rate, Pb-Pb operations and p-Pb operations.

Physics and technical development of accelerators

International Nuclear Information System (INIS)

2000-03-01

About 90 registered participants delivered more than 40 scientific papers. A great part of these presentations were of general interest about running projects such as CIME accelerator at Ganil, IPHI (high intensity proton injector), ESRF (European source of synchrotron radiation), LHC (large hadron collider), ELYSE accelerator at Orsay, AIRIX, and VIVITRON tandem accelerator. Other presentations highlighted the latest technological developments of accelerator components: superconducting cavities, power klystrons, high current injectors..

Completion of the Series Fabrication of the Main Superconducting Quadrupole Magnets of LHC

CERN Document Server

Tortschanoff, Theodor; Papaphilippou, Y; Rossi, L; Schirm, K M; Burgmer, R; Klein, H U; Krischel, D; Schellong, B; Schmidt, P; Durante, M; Payn, A; Rifflet, J M; Simon, F

2007-01-01

By end of November 2006, the last main superconducting quadrupole cold mass needed for the installation was delivered by ACCEL Instruments to CERN. In total, 360 cold masses for the arc regions of the machine and 32 special units dedicated to the dispersion suppressor regions are installed in the LHC ring. The latter ones contain the same main magnet but different types of correctors and are of increased length with respect to the regular arc ones. The end of the fabrication of these magnets coincided with the end of the main dipole deliveries allowing a parallel assembly into their cryostats and installation into the LHC tunnel. The positioning into the tunnel was optimized using the warm field measurements performed in the factory. On the other hand, the correct slot assignment of the quadrupoles was complicated due to the multitude of variants and to the fact that a number of units needed to be replaced by spares which were customized for other slots. The paper gives some final data about the successful fa...

Slice of LHC dipole wiring

CERN Multimedia

Dipole model slice made in 1994 by Ansaldo. The high magnetic fields needed for guiding particles around the Large Hadron Collider (LHC) ring are created by passing 12’500 amps of current through coils of superconducting wiring. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC is the largest superconducting installation ever built. The magnetic field must also be extremely uniform. This means the current flowing in the coils has to be very precisely controlled. Indeed, nowhere before has such precision been achieved at such high currents. 50’000 tonnes of steel sheets are used to make the magnet yokes that keep the wiring firmly in place. The yokes constitute approximately 80% of the accelerator's weight and, placed side by side, stretch over 20 km!

Accelerators at school

International Nuclear Information System (INIS)

Anon.

1986-01-01

Latest subject covered by the CERN Accelerator School was 'Applied Geodesy of Particle Accelerators', which attracted an impressive number of outside participants to CERN for a week in April. Since the forerunners of today's particle accelerators were demonstrated over 50 years ago, the positioning of accelerator components has progressed from the laboratory bench-top to tunnels tens of kilometres long. Despite this phenomenal growth in size, sub-millimetre accuracy is still required

CERN moves into the LHC era

CERN Multimedia

2001-01-01

Dr Hans Eschelbacher (on the left), President of the CERN Council for the last three years, hands over to his successor Maurice Bourquin.  The CERN Council, where the representatives of the 20 Member States of the Organization decide on scientific programmes and financial resources, held its 116th session on 15 December under the chairmanship of Dr. Hans C. Eschelbacher (DE). 'Le Roi est mort. Vive le Roi !' The Large Electron Positron Collider (LEP) era has ended and CERN's future is the Large Hadron Collider (LHC), stated Director General, Prof. Luciano Maiani. He opened his report to Council with a 'homage to LEP', which reached the end of its career during 2000 and is now being dismantled to make way for CERN's next major machine, the LHC collider, in the same 27-kilometre tunnel. The strong indications of a Higgs boson at 115 GeV found during the year were the culmination of LEP's long and distinguished physics career, during which the machine opened up new regimes of precision physics, involvi...

Identification of LHC beam loss mechanism : a deterministic treatment of loss patterns

CERN Document Server

Marsili, Aurélien

CERN's Large Hadron Collider (LHC) is the largest machine ever built, with a total circumference of 26.7 km; and it is the most powerful accelerator ever, both in beam energy and beam intensity. The main magnets are superconducting, keeping the particles into two counter circulating beams, which collide in four interaction points. CERN and the LHC will be described in chap. 1. The superconducting magnets of the LHC have to be protected against particle losses. Depending on the number of lost particles, the coils of the magnets will become normal conducting and/or will be damaged. To avoid these events a beam loss monitoring (BLM) system was installed to measure the particle loss rates. If the predefined safe thresholds of loss rates are exceeded, the beams are directed out of the accelerator ring towards the beam dump. The detectors of the BLM system are mainly ionization chambers located outside of the cryostats. In total, about 3500 ionisation chambers are installed. Further challenges include the high dyna...

Software Tools for Electrical Quality Assurance in the LHC

CERN Document Server

Bednarek, Mateusz

2011-01-01

There are over 1600 superconducting magnet circuits in the LHC machine. Many of them consist of a large number of components electrically connected in series. This enhances the sensitivity of the whole circuits to electrical faults of individual components. Furthermore, circuits are equipped with a large number of instrumentation wires, which are exposed to accidental damage or swapping. In order to ensure safe operation, an Electrical Quality Assurance (ELQA) campaign is needed after each thermal cycle. Due to the complexity of the circuits, as well as their distant geographical distribution (tunnel of 27km circumference divided in 8 sectors), suitable software and hardware platforms had to be developed. The software combines an Oracle database, LabView data acquisition applications and PHP-based web follow-up tools. This paper describes the software used for the ELQA of the LHC.

Software tools for electrical quality assurance in the LHC

International Nuclear Information System (INIS)

Bednarek, M.; Ludwin, J.

2012-01-01

There are over 1600 superconducting magnet circuits in the LHC machine. Many of them consist of a large number of components electrically connected in series. This enhances the sensitivity of the whole circuits to electrical faults of individual components. Furthermore, circuits are equipped with a large number of instrumentation wires, which are exposed to accidental damage or swapping. In order to ensure safe operation, an Electrical Quality Assurance (ELQA) campaign is needed after each thermal cycle. Due to the complexity of the circuits, as well as their distant geographical distribution (tunnel of 27 km circumference divided in 8 sectors), suitable software and hardware platforms had to be developed. The software combines an Oracle database, LabView data acquisition applications and PHP-based web follow-up tools. This paper describes the software used for the ELQA of the LHC. (authors)

Le CERN réagit à l'augmentation du coût du LHC à son achèvement

CERN Multimedia

CERN Press Office. Geneva

2001-01-01

Director-General, Luciano Maiani, stressed that CERN was now fully engaged in the LHC and outlined the first moves to react to the increased cost to completion of the LHC. The new accelerator is an extremely complex, high-tech project which CERN is building under very severe conditions. However, the technical challenges are solved and industrial production of accelerator elements, and installation are starting.

22 August 2014 - Members of the International Business Council of the World Economic Forum led by Managing Director and Member of the Managing Board P. Rösler

CERN Multimedia

Gadmer, Jean-Claude

2014-01-01

Visiting the LHC tunnel at point 5 with Director-General R. Heuer, Director of Accelerators and Technology F. Bordry, Head of International Relations R. Voss and Deputy Head of International Relations E. Tsesmelis

Reliability review of the LHC collimators low level control system

International Nuclear Information System (INIS)

Masi, A.; Donze, M.; Losito, R.

2011-01-01

The LHC collimators' low level control system is responsible for the positioning, with an accuracy of a few um, of more than 500 motor axes located around the entire LHC tunnel and synchronized at us level,The collimators' axes position is verified in Real Time, monitoring at 100 Hz more than 700 LVDT positioning sensors. Apart from the challenging requirements of timing and positioning accuracy, the system is characterized by a high level of reliability since the collimators have the crucial function of machine protection. In this paper we focus on the architectural and technical choices adopted to guarantee the level of reliability required by the application. We also present the tools and solutions developed to manage this huge control system making the support easier and faster for its operation. (authors)

Beam Loss Patterns at the LHC Collimators Measurements & Simulations

CERN Document Server

Böhlen, Till Tobias

2008-01-01

The Beam Loss Monitoring (BLM) system of the Large Hadron Collider (LHC) detects particle losses of circulating beams and initiates an emergency extraction of the beam in case that the BLM thresholds are exceeded. This protection is required as energy deposition in the accelerator equipment due to secondary shower particles can reach critical levels; causing damage to the beam-line components and quenches of superconducting magnets. Robust and movable beam line elements, so-called collimators, are the aperture limitations of the LHC. Consequently, they are exposed to the excess of lost beam particles and their showers. Proton loss patterns at LHC collimators have to be determined to interpret the signal of the BLM detectors and to set adequate BLM thresholds for the protection of collimators and other equipment in case of unacceptably increased loss rates. The first part of this work investigates the agreement of BLM detector measurements with simulations for an LHC-like collimation setup. The setup consists ...

Design Considerations for the LHC 200 MHz RF System

CERN Document Server

Boussard, Daniel; Kindermann, H P; Linnecar, Trevor Paul R; Marque, S; Tückmantel, Joachim

2000-01-01

The longitudinal beam transfer from the SPS into the LHC 400 MHz buckets will not be free of losses without a lower frequency capture system and a fast longitudinal damping system in LHC. We present a complete study of a combined system using four identical copper cavities at 200 MHz delivering 3 MV total CW voltage and having still enough bandwidth to achieve fast longitudinal damping. The shape of a cavity was designed according to the accelerating mode performance, its tuning and the higher order mode spectrum with respect to the LHC beam lines and their possible attenuation. The possibility to park the cavities during coast was included. The local heat load and the corresponding cooling water distribution as well as deformations were studied and techniques to build the cavity with all ports at low cost are proposed. The parameters of the RF generators, couplers and detuning are determined. Simulations of the total LHC RF system incorporating real delays, generator bandwidth and the control loops confirm t...

Transverse Emittance Measurement and Preservation at the LHC

CERN Document Server

AUTHOR|(CDS)2082907

The Large Hadron Collider (LHC) at CERN is a high energy storage ring that provides proton and heavy ion collisions to study fundamental particle physics. The luminosity production is closely linked to emittance preservation in the accelerator. The transverse emittance is the phase space density of the beam and should be conserved when the particle beam is transformed through the accelerator. Perturbing effects, however, can lead to emittance increase and hence luminosity degradation. Measuring the emittance growth is a complex task with high intensity beams and changing energies. The machine optics and the transverse beam size have to be measured as accurately as possible. Beta function measurements with k-modulation will be discussed. With this method the quadrupole focussing strength is varied and the resulting tune change is traced to determine the beta function at the quadrupole. A new k-modulation measurement tool was developed for the LHC. The fully automatic and online measurement system takes constra...

Machine Induced Experimental Background Conditions in the LHC

CERN Document Server

Levinsen, Yngve Inntjore; Stapnes, Steinar

2012-09-19

The Large Hadron Collider set a new energy record for particle accelerators in late 2009, breaking the previous record held by Tevatron of 2 TeV collision energy. The LHC today operates at a collision energy of 7 TeV. With higher beam energy and intensity, measures have to be taken to ensure optimal experimental conditions and safety of the machine and detectors. Machine induced experimental background can severely reduce the quality of experimental triggers and track reconstruction. In a worst case, the radiation levels can be damaging for some of the subdetectors. The LHC is a particular challenge in this regard due to the vastly different operating conditions of the different experiments. The nominal luminosity varies by four orders of magnitude. The unprecedented stored beam energy and the amount of superconducting elements can make it challenging to protect the accelerator itself as well. In this work we have simulated and measured the machine induced background originating from various sources: the beam...

Cryogenic Risk Assessments before Works in the LHC Tunnel

CERN Multimedia

CERN. Geneva

2016-01-01

Tests conducted in 2013/4 demonstrated that a small, residual risk to expose personnel to a helium spill exists in the LHC. Helium spills with a mass flow of less than 100 g s^-1 could be caused by workers accidentally damaging sensitive equipment in the cryogenic distribution system, such as instrumentation feedthroughs. In order to control this risk, a cryogenic risk assessment for all works taking place in the vicinity of such sensitive equipment is mandatory. The risk assessment and its recommendations are approved by the hierarchy and the complex manager before work can start. After introducing the risk assessment procedure, I will give some feedback on its implementation and present status.

LEP tunnel monorail

CERN Multimedia

1985-01-01

A monorail from CERN's Large Electron Positron collider (LEP, for short). It ran around the 27km tunnel, transporting equipment and personnel. With its 27-kilometre circumference, LEP was the largest electron-positron accelerator ever built and ran from 1989 to 2000. During 11 years of research, LEP's experiments provided a detailed study of the electroweak interaction. Measurements performed at LEP also proved that there are three – and only three – generations of particles of matter. LEP was closed down on 2 November 2000 to make way for the construction of the Large Hadron Collider in the same tunnel.

Inductive Soldering of the Junctions of the Main Superconducting Busbars of the LHC

CERN Document Server

Jacquemod, A; Schauf, F; Skoczen, Blazej; Tock, J P

2004-01-01

The Large Hadron Collider (LHC) is the next world-facility for the high energy physics community, presently under construction at CERN, Geneva. The LHC will bring into collisions intense beams of protons and ions. The main components of the LHC are the twin-aperture high-field superconducting cryomagnets that will be installed in the existing 26.7-km long tunnel. They are powered in series by superconducting Nb-Ti cables. Along the machine, about 60 000 joints between superconducting cables must be realised in-situ during the installation. Ten thousands of them, rated at 13 000 A, are involved in the powering scheme of the main dipoles and quadrupoles. To meet the requirements of the cryogenic budget, an electrical resistance at operating temperature (1.9 K) lower than 0.6 nW has to be achieved. The induction soldering technology was selected for this purpose. After a brief introduction to the LHC project, the constraints and requirements are listed. Then, the applied solution is detailed. The splices of the ...

12 December 2013 - Sir Konstantin Novoselov, Nobel Prize in Physics 2010, signing the guest book with International Relations Adviser E. Tsesmelis; visiting the ATLAS experimental cavern with Spokesperson D. Charlton; in the LHC tunnel with Technology Department Head F. Bordry. I. Antoniadis, CERN Theory Group Leader, accompanies throughout.

CERN Multimedia

Anna Pantelia

2013-01-01

12 December 2013 - Sir Konstantin Novoselov, Nobel Prize in Physics 2010, signing the guest book with International Relations Adviser E. Tsesmelis; visiting the ATLAS experimental cavern with Spokesperson D. Charlton; in the LHC tunnel with Technology Department Head F. Bordry. I. Antoniadis, CERN Theory Group Leader, accompanies throughout.

LHC beampipe section

CERN Multimedia

A short section of the LHC beam-pipe including beam screen. In the LHC, particles circulate under vacuum. The vacuum chamber can be at room temperature (for example, in the experimental areas), or at cryogenic temperature, in the superconductive magnets. This piece is located in the superconductive magnets. The outer pipe is the vacuum chamber, which is in contact with the magnets, at cryogenic temperature (1.9K). It is called the “cold bore”. The inner tube is the beam screen. Its main goal is to protect the magnets from the heat load coming from the synchrotron radiation. Indeed, when high energy protons’ trajectory is bent, photons are emitted by the beam. They are intercepted by the beam screen. The temperature of the beam screen is kept between 5 and 20K by a circulation of gaseous helium in the small pipes on both sides of the beam screen. As those surfaces are at cryogenic temperature. The residual gas present in the accelerator is sticking on the surfaces. This phenomenon called “adsorption”...

Switch on to the LHC!

CERN Multimedia

CERN Bulletin

2010-01-01

The LHC is preparing to collide beams at 3.5 TeV for the first time ever! Be part of the event and follow live what goes on at the world’s most powerful particle accelerator by connecting to LHC1. Hereafter we give you a key to understand the display as well as a typical event display from the ATLAS and CMS experiments. Click on the image to enlarge it 1. This is the energy of beams. 1 TeV=1000 GeV. The LHC set the energy world’s record of 3.48 TeV per beam, today, 19 March 2010. 2. Intensity of, respectively, B1 (blue) and B2 (red). 3. The information in these boxes can vary. Operators display the graphs that are relevant to the specific operation. 4. Most of the flags are set automatically. They provide a quick summary of the machine status. In order to have collisions the ‘Stable Beams’ flag must be set to green. 5. Here operators write down their messages to the experiments. Often, they write the ongoing activity, followed by the plan for the coming hou...

Radiation Tests on the Complete System of the Instrumentation of the LHC Cryogenics at the CERN Neutrinos to Gran Sasso (CNGS) Test Facility

CERN Document Server

Gousiou, E; Casas Cubillos, J; de la Gama Serrano, J

2009-01-01

There are more than 6000 electronic cards for the instrumentation of the LHC cryogenics, housed in crates and distributed around the 27 km tunnel. Cards and crates will be exposed to a complex radiation field during the 10 years of LHC operation. Rad-tol COTS and rad-hard ASIC have been selected and individually qualified during the design phase of the cards. The test setup and the acquired data presented in this paper target the qualitative assessment of the compliance with the LHC radiation environment of an assembled system. It is carried out at the CNGS test facility which provides exposure to LHC-like radiation field.

Accelerator Technology: Geodesy and Alignment for Particle Accelerators

CERN Document Server

Missiaen, D

2013-01-01

This document is part of Subvolume C 'Accelerators and Colliders' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the the Section '8.9 Geodesy and Alignment for Particle Accelerators' of the Chapter '8 Accelerator Technology' with the content: 8.9 Geodesy and Alignment for Particle Accelerators 8.9.1 Introduction 8.9.2 Reference and Co-ordinate Systems 8.9.3 Definition of the Beam Line on the Accelerator Site 8.9.4 Geodetic Network 8.9.5 Tunnel Preliminary Works 8.9.6 The Alignment References 8.9.7 Alignment of Accelerator Components 8.9.8 Permanent Monitoring and Remote Alignment of Low Beta Quadrupoles 8.9.9 Alignment of Detector Components

High Filed Magnets: Niobium-titanium and beyond

Energy Technology Data Exchange (ETDEWEB)

Waloschek, Pedro

1990-09-15

To guide proton beams at tomorrow's higher energies - for the LHC project in CERN's existing LEP tunnel, and for the US Superconducting Supercollider (SSC) construction project - accelerator physicists are pushing for more powerful magnets.

The Physics Programme Of The MoEDAL Experiment At The LHC

CERN Document Server

Acharya, B.; Bernabeu, J.; Campbell, M.; Cecchini, S.; Chwastowski, J.; De Montigny, M.; Derendarz, D.; De Roeck, A.; Ellis, J.R.; Fairbairn, M.; Felea, D.; Frank, M.; Frekers, D.; Garcia, C.; Giacomelli, G.; Giorgini, M.; Hasegan, D.; Hott, T.; J.Jak\\r u; Katre, A.; Kim, D-W.; King, M.G.L.; Kinoshita, K.; Lacarrere, D.; Lee, S.C.; Leroy, C.; Margiotta, A.; Mauri, N.; Mavromatos, N.E.; Mermod, P.; Mitsou, V.A.; Orava, R.; Pasqualini, L.; Patrizii, L.; Pavalas, G.E.; Pinfold, J.L.; Platkevic, M.; Popa, V.; Pozzato, M.; Pospisil, S.; Rajantie, A.; Sahnoun, Z.; Sakellariadou, M.; Sarkar, S.; Semenoff, G.; Sirri, G.; Sliwa, K.; Soluk, R.; Spurio, M.; Srivastava, Y.N.; Staszewski, R.; Swain, J.; Tenti, M.; Togo, V.; Trzebinski, M.; Tuszynski, J.A.; Vento, V.; Vives, O.; Vykydal, Z.; Widom, A.; Yoon, J.H.

2014-01-01

The MoEDAL experiment at Point 8 of the LHC ring is the seventh and newest LHC experiment. It is dedicated to the search for highly ionizing particle avatars of physics beyond the Standard Model, extending significantly the discovery horizon of the LHC. A MoEDAL discovery would have revolutionary implications for our fundamental understanding of the Microcosm. MoEDAL is an unconventional and largely passive LHC detector comprised of the largest array of Nuclear Track Detector stacks ever deployed at an accelerator, surrounding the intersection region at Point 8 on the LHC ring. Another novel feature is the use of paramagnetic trapping volumes to capture both electrically and magnetically charged highly-ionizing particles predicted in new physics scenarios. It includes an array of TimePix pixel devices for monitoring highly-ionizing particle backgrounds. The main passive elements of the MoEDAL detector do not require a trigger system, electronic readout, or online computerized data acquisition. The aim of this...

The LHC Physics Centre at CERN

CERN Document Server

CERN Bulletin

2010-01-01

As the LHC goes on line for its first exploration of the new high-energy frontier, CERN is also getting ready to enhance the support it provides for the analysis and interpretation of the emerging data.    The LHC Physics Centre at CERN (LPCC) has started up over the past couple of months, beginning with a series of initiatives ranging from Workshops to lectures for students. More details about the LPCC will be featured in a forthcoming Bulletin article. In the meantime, you can consult the LPCC web page, now available at http://cern.ch/lpcc. This offers the high energy physics community a portal to the LPCC's activities, as well as to useful resources, tools and information about the LHC physics programme, the progress of accelerator operations, relevant workshops and events around the world, and much more. The LPCC will shortly begin issuing a weekly bulletin of its own, distributed by e-mail. Members of the CERN physics community and subscribers to the CERN Bulletin will receive the ...

The LHC's suppliers come up trumps

CERN Multimedia

2006-01-01

Four of the LHC Project's most exceptional suppliers have just been honoured in the fifth Golden Hadron awards ceremony. For the first time, a CERN team was among the prize-winners. The CERN main workshop (Mechanical and Materials Engineering group, TS/MME) received the Golden Hadron Award at the prize-giving ceremony held at the Globe. From left to right, Saïd Atieh (TS/MME), Vincent Vuillemin (TS/MME group leader), Michel Caccioppoli (TS/MME), Lyn Evans (LHC Project Leader), Marc Polini (TS/MME-MS section leader), Jean-Luc Gayraud (Cegelec), Jean-Paul Bacher (TS/MME-AS section leader) and Paolo Ciriani (head of the TS Department). Flexible, responsive, committed... all fitting adjectives to describe the recipients of the fifth Golden Hadron awards. The prizes, designed to honour the LHC Project's best suppliers, were awarded to a total of four suppliers, including two that are involved in the final accelerator assembly work: proof, if it were needed, that the project has now entered its final phase. Drak...

Cryogenics for LHC experiments

CERN Multimedia

2001-01-01

Cryogenic systems will be used by LHC experiments to maximize their performance. Institutes around the world are collaborating with CERN in the construction of these very low temperature systems. The cryogenic test facility in hall 180 for ATLAS magnets. High Energy Physics experiments have frequently adopted cryogenic versions of their apparatus to achieve optimal performance, and those for the LHC will be no exception. The two largest experiments for CERN's new flagship accelerator, ATLAS and CMS, will both use large superconducting magnets operated at 4.5 Kelvin - almost 270 degrees below the freezing point of water. ATLAS also includes calorimeters filled with liquid argon at 87 Kelvin. For the magnets, the choice of a cryogenic version was dictated by a combination economy and transparency to emerging particles. For the calorimeters, liquid argon was selected as the fluid best suited to the experiment's physics requirements. High Energy Physics experiments are the result of worldwide collaborations and...

The LHC superconducting cavities

CERN Document Server

Boussard, Daniel; Häbel, E; Kindermann, H P; Losito, R; Marque, S; Rödel, V; Stirbet, M

1999-01-01

The LHC RF system, which must handle high intensity (0.5 A d.c.) beams, makes use of superconducting single-cell cavities, best suited to minimizing the effects of periodic transient beam loading. There will be eight cavities per beam, each capable of delivering 2 MV (5 MV/m accelerating field) at 400 MHz. The cavities themselves are now being manufactured by industry, using niobium-on-copper technology which gives full satisfaction at LEP. A cavity unit includes a helium tank (4.5 K operating temperature) built around a cavity cell, RF and HOM couplers and a mechanical tuner, all housed in a modular cryostat. Four-unit modules are ultimately foreseen for the LHC (two per beam), while at present a prototype version with two complete units is being extensively tested. In addition to a detailed description of the cavity and its ancillary equipment, the first test results of the prototype will be reported.

LHC Report: machine development

CERN Multimedia

Rogelio Tomás García for the LHC team

2015-01-01

Machine development weeks are carefully planned in the LHC operation schedule to optimise and further study the performance of the machine. The first machine development session of Run 2 ended on Saturday, 25 July. Despite various hiccoughs, it allowed the operators to make great strides towards improving the long-term performance of the LHC.   The main goals of this first machine development (MD) week were to determine the minimum beam-spot size at the interaction points given existing optics and collimation constraints; to test new beam instrumentation; to evaluate the effectiveness of performing part of the beam-squeezing process during the energy ramp; and to explore the limits on the number of protons per bunch arising from the electromagnetic interactions with the accelerator environment and the other beam. Unfortunately, a series of events reduced the machine availability for studies to about 50%. The most critical issue was the recurrent trip of a sextupolar corrector circuit –...

Taiwan links up to world's first LHC computing grid project

CERN Multimedia

2003-01-01

"Taiwan's Academia Sinica was linked up to the Large Hadron Collider (LHC) Computing Grid Project last week to work jointly with 12 other countries to construct the world's largest and most powerful particle accelerator" (1/2 page).

Taiwan links up to world's 1st LHC Computing Grid Project

CERN Multimedia

2003-01-01

Taiwan's Academia Sinica was linked up to the Large Hadron Collider (LHC) Computing Grid Project to work jointly with 12 other countries to construct the world's largest and most powerful particle accelerator

ATLAS Tracker Upgrade: Silicon Strip Detectors for the sLHC

CERN Document Server

Koehler, M; The ATLAS collaboration

2010-01-01

To extend the physics potential of the Large Hadron Colider (LHC) at CERN, upgrades of the accelerator complex and the detectors towards the Super-LHC (sLHC) are foreseen. The upgrades, separated in Phase-1 and Phase-2, aim at increasing the luminosity while leaving the energy of the colliding particles (7 TeV per proton beam) unchanged. After the Phase-2 upgrade the instantaneous luminosity will be a factor of 5-10 higher than the design luminosity of the LHC. Due to the increased track rate and extreme radiation levels for the tracking detectors, upgrades of the detectors are necessary. At ATLAS, one of the two general purpose detectors at the LHC, the current inner detector will be replaced by an all-silicon tracker. This article describes the plans for the Phase-2 upgrade of the silicon strip detector of ATLAS. Radiation hard n-in-p silicon detectors with shorter strips than currently installed in ATLAS are planned. Results of measurements with these sensors and plans for module designs will be discussed.

The LHC string2 supervision system

CERN Document Server

Mayya, Y S; Sicard, Claude Henri

2002-01-01

This paper describes the implementation of the supervision system for the LHC Prototype Full-Cell also known as String 2. The supervision application is based on a commercial package targeted to industrial controls, but because of the complexity and the specifics of such a system, integration with custom components is necessary in order to merge the industrial requirements with the specificity of the accelerator controls.

Latin American collaboration to the CERN-LHC accelerator assembly and its projects

Energy Technology Data Exchange (ETDEWEB)

Sajo B, L. [Universidad Simon Bolivar, Nuclear Physics Laboratory, Caracas 1080-A (Venezuela, Bolivarian Republic of)

2016-10-15

Summary of Latin American (LA) scientists main contributions to the construction of a heavy ion detector assembly currently operating at the Large Hadron Collider (LHC) at CERN, Geneva,Switzerland is given with description of the provided support for posterior data analysis. This joint effort highlights the much needed recognition of LA as a technologically emerging region. It has also shown a net benefit in development of science for our region. Details are given on the LHC-Alice experiment where several LA countries have contributed with innovative technological solutions. These include the ability to build part of the numerous detectors, including the central barrel as well as acquired knowledge on aspects concerning high energy dosimetry and radiation damage. (Author)

Latin American collaboration to the CERN-LHC accelerator assembly and its projects

International Nuclear Information System (INIS)

Sajo B, L.

2016-10-01

Summary of Latin American (LA) scientists main contributions to the construction of a heavy ion detector assembly currently operating at the Large Hadron Collider (LHC) at CERN, Geneva,Switzerland is given with description of the provided support for posterior data analysis. This joint effort highlights the much needed recognition of LA as a technologically emerging region. It has also shown a net benefit in development of science for our region. Details are given on the LHC-Alice experiment where several LA countries have contributed with innovative technological solutions. These include the ability to build part of the numerous detectors, including the central barrel as well as acquired knowledge on aspects concerning high energy dosimetry and radiation damage. (Author)

2nd report from the LHC performance workshop

CERN Multimedia

Bulletin's correspondent from Chamonix

2012-01-01

Tuesday's sessions were spent looking ahead to the possibilities for 2012. The morning started with the experiments' desiderata for the year with the key requirement being either discovery of Higgs or exclusion at the 95% confidence level down to 115 GeV. To achieve this Atlas and CMS will need an integrated luminosity in the order of 15 fb-1.   Potential improvements to performance and machine availability were then discussed with presentations on maximising the time the LHC is delivering collisions to the experiments, and the potential of the injectors to provide bunches with higher intensities and the smallest possible beam size (these fold directly into higher collision rates). Machine performance will also be improved in 2012 thanks to a number of mitigation measures taken during the Christmas stop aimed at reducing the effects of radiation on the electronics situated in the LHC tunnel. The possibility for running at a beam energy of 4 TeV was put on the table. Discussions w...

The Control System for the Cryogenics in the LHC Tunnel [First Experience and Improvements

CERN Document Server

Gomes, P; Casas, J; Fluder, C; Fortescue, E; Le Roux, P; Penacoba, G; Pezzetti, M; Soubiran, M; Tovar, A; Zwalinski, L

2010-01-01

The Large Hadron Collider (LHC) was commissioned at CERN and started operation with beams in 2008. Several months of operation in nominal cryogenic conditions have triggered an optimisation of the process functional analysis. This lead to a few revisions of the control logic, which were realised on-the-fly. During the 2008-09 shut-down, and in order to enhance the safety, availability and operability of the LHC cryogenics, a major rebuild of the logic and several hardware modifications were implemented. The databases, containing instruments and controls in-formation, are being rationalized; the automatic tool, that extracts data for the control software, is being simplified. This paper describes the main improvements and sug-gests perspectives of further developments.

Lighting the way: how emergency lights survive radiation

CERN Multimedia

Stephanie Hills

2016-01-01

 LHC tunnel emergency lights are part of an essential safety system if you ever need to evacuate.   As part of the design of a new emergency lighting system for the CERN accelerator complex a new design for a radiation resistant power supply has been produced. The design is available from the Open Hardware Repository. (Video: Christoph Madsen/ CERN) Just like a fridge, you only need the lights on in the LHC tunnel when you are in there; but the emergency lights are part of an essential safety system if you ever need to evacuate.  Fortunately, tunnel evacuations are very rare, but if you work there, you need to know that you can rely on the emergency lighting to guide you to safety. When the LHC machine is operating, it is a harsh environment – people are most definitely not allowed access – and the lighting systems need to withstand the effects of radiation to ensure that they will still work when the LHC is switched off and people ar...

The Large Hadron Collider in the LEP tunnel

International Nuclear Information System (INIS)

Brianti, G.; Huebner, K.

1987-01-01

The status of the studies for the CERN Large Hadron Collider (LHC) is described. This collider will provide proton-proton collisions with 16 TeV centre-of-mass energy and a luminosity exceeding 10 33 cm -2 s -1 per interaction point. It can be installed in the tunnel of the Large Electron-Positron Storage Ring (LEP) above the LEP elements. It will use superconducting magnets of a novel, compact design, having two horizontally separated channels for the two counter-rotating bunched proton beams, which can collide in a maximum of seven interaction points. Collisions between protons of the LHC and electrons of LEP are also possible with a centre-of-mass energy of up to 1.8 TeV and a luminosity of up to 2 x 10 32 cm -2 s -1 . (orig.)

Deformation Monitoring of the Spallation Neutron Source (SNS) Tunnels

CERN Document Server

Error, J J; Fazekas, J J; Helus, S A; Maines, J R

2005-01-01

The SNS Project is a 1.4 MW accelerator-based neutron source located at Oak Ridge National Laboratory in Oak Ridge, Tennessee. For shielding purposes, a 17 foot berm of native soil has been constructed on top of the accelerator tunnel system. This backfill has caused ongoing settlement of the tunnels. The settlement has been monitored by the SNS Survey and Alignment Group at regular intervals, in order to discover the patterns of deformation, and to determine when the tunnels will be stable enough for precise alignment of beam line components. The latest monitoring results indicate that the settlement rate has significantly decreased. This paper discusses the techniques and instrumentation of the monitoring surveys, and provides an analysis of the results.

The LHC and its electrotechnical challenges

International Nuclear Information System (INIS)

Bordry, F.

2010-01-01

After a brief presentation of the CERN, the European organization for nuclear research, this article presents the LHC, the Large Hadron Collider, the largest and most powerful particle accelerator in the world. The project somehow started in 1984 and relies on several technological challenges which are herein described: superconducting magnets (their characteristics and cryogenic operation), operation security with particularly high energies stored in magnets and beams, LHC electricity supply (electric circuits with high time constant, a required precision and reproducibility of the magnetic field during all the operation phases, importance of power converters). Then the author evokes the starting procedures, some serious damages which occurred, and the restart of the operation period with spectacular results in terms of beam energy. Future experiments and expected results are also evoked

Quench protection of the LHC inner triplet quadrupoles built at Fermilab

CERN Document Server

Bauer, P; Chiesa, L; Di Marco, J; Fehér, S; Lamm, M J; McInturff, A D; Nobrega, A; Orris, D; Tartaglia, M; Tompkins, J C; Zlobin, A V

2001-01-01

High gradient quadrupoles are being developed by the US-LHC Accelerator project for the LHC interaction region inner triplets. These 5.5 m long magnets have a single 70 mm aperture and operate in superfluid helium at a peak gradient of 215 T/m. Through the construction and test of eight 2 meter long model quadrupoles, strip heaters of various geometries and insulation thicknesses have proven to be effective in protecting the magnets from excessively high coil temperatures and coil voltages to ground. This paper reports on the results of the model program to optimize the heater performance within the context of the LHC inner triplet electrical power and quench detection scheme. (6 refs).

Reliability analysis for the quench detection in the LHC machine

CERN Document Server

Denz, R; Vergara-Fernández, A

2002-01-01

The Large Hadron Collider (LHC) will incorporate a large amount of superconducting elements that require protection in case of a quench. Key elements in the quench protection system are the electronic quench detectors. Their reliability will have an important impact on the down time as well as on the operational cost of the collider. The expected rates of both false and missed quenches have been computed for several redundant detection schemes. The developed model takes account of the maintainability of the system to optimise the frequency of foreseen checks, and evaluate their influence on the performance of different detection topologies. Seen the uncertainty of the failure rate of the components combined with the LHC tunnel environment, the study has been completed with a sensitivity analysis of the results. The chosen detection scheme and the maintainability strategy for each detector family are given.

LHC Report: Summertime and the living is ZZ (and WW etc.)

CERN Document Server

Mike Lamont for the LHC Team

2012-01-01

The LHC had a rocky recovery from the extended luminosity calibration runs, and on Saturday 21 July a number of fills were lost due to beam instabilities. The situation was stabilised by temporarily backing off increasing bunch intensity and, in fact, the next 24 hours saw a record delivery of around 260 pb-1 to each of the ATLAS and CMS experiments.   This good performance continued the following week with around 55% of the time spent in "stable beams". Over 1 fb-1 was delivered to ATLAS and CMS. This was despite some timeouts for access and operational development. Peak luminosity is down about 10% from the highs earlier in the year, but the LHC is regularly enjoying long fills in the 12 to 15 hour range. Here we are seeing the benefits of the extensive consolidation work to mitigate the effects of radiation to electronics in the LHC tunnel and the continuing efforts to improve overall reliability. Combining data runs from 2011 and 2012, LHCb crossed the 2 fb-1 mark last Mond...

The light at the end of the tunnel gets brighter

CERN Multimedia

Anaïs Schaeffer

2014-01-01

With the LHC restart just a few months away, the future of the accelerator is as hot a topic as ever. In June, in the framework of the Medium-Term Plan, the CERN Council endorsed the construction of the LHC's successor, the High-Luminosity LHC (HL-LHC), which is set to take over from 2025 onwards.   Group photo at the HiLumi LHC/LARP Annual Meeting, 2013. “This marks an important stage in the approval process of the HL-LHC,” says project coordinator Lucio Rossi. “It all started back in 2010 when the project was launched. In 2011, we obtained a European Commission grant for the conceptual design study under the Seventh Framework Programme (FP7) and, in 2013, the CERN Council identified the project as a priority at its special session dedicated to the European Strategy for Particle Physics. Finally, the Council this year confirmed the priority status of the HL-LHC project in the CERN scientific and financial programme by approving the Medium-Term Plan for ...

LHC Report: The shutdown work nearing completion

CERN Multimedia

CERN Bulletin

2011-01-01

The work planned for the LHC injector chain during the winter shutdown is nearing completion. The PS Booster (PSB) and PS will be closed to access next week, and the control of machine access will be transferred to the CERN Control Centre in preparation for the resumption of machine operation. Hardware tests are being performed in all the machines.   Tests are under way in the LHC tunnel. The technical teams are putting the finishing touches to the work planned for the winter shutdown. At the Linac2, the PS Booster and the PS, work will be completed next week and hardware tests will be carried out soon after. POPS, the new powering system for the PS, will be commissioned for the first time in the coming days after the necessary preliminary tests have been carried out. At the SPS, various magnets have been replaced over recent weeks and the performance tests on the main power supply and other hardware tests will be able to start shortly. After that, the machine will be ready for operation with b...

Implementation of a Direct Link between the LHC Beam Interlock System and the LHC Beam Dumping System Re-Triggering Lines

CERN Document Server

Gabourin, S; Denz, R; Magnin, N; Uythoven, J; Wollmann, D; Zerlauth, M; Vatansever, V; Bartholdt, M; Bertsche, B; Zeiler, P

2014-01-01

To avoid damage of accelerator equipment due to impacting beam, the controlled removal of the LHC beams from the collider rings towards the dump blocks must be guaranteed at all times. When a beam dump is demanded, the Beam Interlock System communicates this request to the Trigger Synchronisation and Distribution System of the LHC Beam Dumping System. Both systems were built according to high reliability standards. To further reduce the risk of incapability to dump the beams in case of correlated failures in the Trigger Synchronisation and Distribution System, a new direct link from the Beam Interlock System to the re-triggering lines of the LHC Beam Dumping System will be implemented for the start-up with beam in 2015. The link represents a diverse redundancy to the current implementation, which should neither significantly increase the risk for so-called asynchronous beam dumps nor compromise machine availability. This paper describes the implementation choices of this link. Furthermore the results of a rel...

A Beam Quality Monitor for LHC Beams in the SPS

CERN Document Server

Papotti, G

2008-01-01

The SPS Beam Quality Monitor (BQM) system monitors the longitudinal parameters of the beam before extraction to the LHC to prevent losses and degradation of the LHC luminosity by the injection of low quality beams. It is implemented in two priority levels. At the highest level the SPS-LHC synchronization and global beam structure are verified. If the specifications are not met, the beam should be dumped in the SPS before extraction. On the second level, individual bunch position, length and stability are checked for beam quality assessment. Tolerances are adapted to the mode of operation and extraction to the LHC can also be inhibited. Beam parameters are accessed by acquiring bunch profiles with a longitudinal pick up and fast digital oscilloscope. The beam is monitored for instabilities during the acceleration cycle and thoroughly checked a few ms before extraction for a final decision on extraction interlock. Dedicated hardware and software components implementing fast algorithms are required. In this pape...

Upgrade of the LHC magnet interconnections thermal shielding

Energy Technology Data Exchange (ETDEWEB)

Musso, Andrea; Barlow, Graeme; Bastard, Alain; Charrondiere, Maryline; Deferne, Guy; Dib, Gaëlle; Duret, Max; Guinchard, Michael; Prin, Hervé; Craen, Arnaud Vande; Villiger, Gilles [CERN European Organization for Nuclear Research, Meyrin 1211, Geneva 23, CH (Switzerland); Chrul, Anna [The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, ul.Radzikowskiego 152, 31-324 Krakow (Poland); Damianoglou, Dimitrios [NTUA National Technical University of Athens, Heeron Polytechniou 9, 15780 Zografou (Greece); Strychalski, Michał [Wroclaw University of Technology, Faculty of Mechanical and Power Engineering, Wyb. Wyspianskiego 27, Wroclaw, 50-370 (Poland); Wright, Loren [Lancaster University, Bailrigg, Lancaster, LA1 4YW (United Kingdom)

2014-01-29

The about 1700 interconnections (ICs) between the Large Hadron Collider (LHC) superconducting magnets include thermal shielding at 50-75 K, providing continuity to the thermal shielding of the magnet cryostats to reduce the overall radiation heat loads to the 1.9 K helium bath of the magnets. The IC shield, made of aluminum, is conduction-cooled via a welded bridge to the thermal shield of the adjacent magnets which is actively cooled. TIG welding of these bridges made in the LHC tunnel at installation of the magnets induced a considerable risk of fire hazard due to the proximity of the multi-layer insulation of the magnet shields. A fire incident occurred in one of the machine sectors during machine installation, but fortunately with limited consequences thanks to prompt intervention of the operators. LHC is now undergoing a 2 years technical stop during which all magnet's ICs will have to be opened to consolidate the magnet electrical connections. The IC thermal shields will therefore have to be removed and re-installed after the work is completed. In order to eliminate the risk of fire hazard when re-welding, it has been decided to review the design of the IC shields, by replacing the welded bridges with a mechanical clamping which also preserves its thermal function. An additional advantage of this new solution is the ease in dismantling for maintenance, and eliminating weld-grinding operations at removal needing radioprotection measures because of material activation after long-term operation of the LHC. This paper describes the new design of the IC shields and in particular the theoretical and experimental validation of its thermal performance. Furthermore a status report of the on-going upgrade work in the LHC is given.

Upgrade of the LHC magnet interconnections thermal shielding

Science.gov (United States)

Musso, Andrea; Barlow, Graeme; Bastard, Alain; Charrondiere, Maryline; Chrul, Anna; Damianoglou, Dimitrios; Deferne, Guy; Dib, Gaëlle; Duret, Max; Guinchard, Michael; Prin, Hervé; Strychalski, Michał; Craen, Arnaud Vande; Villiger, Gilles; Wright, Loren

2014-01-01

The about 1700 interconnections (ICs) between the Large Hadron Collider (LHC) superconducting magnets include thermal shielding at 50-75 K, providing continuity to the thermal shielding of the magnet cryostats to reduce the overall radiation heat loads to the 1.9 K helium bath of the magnets. The IC shield, made of aluminum, is conduction-cooled via a welded bridge to the thermal shield of the adjacent magnets which is actively cooled. TIG welding of these bridges made in the LHC tunnel at installation of the magnets induced a considerable risk of fire hazard due to the proximity of the multi-layer insulation of the magnet shields. A fire incident occurred in one of the machine sectors during machine installation, but fortunately with limited consequences thanks to prompt intervention of the operators. LHC is now undergoing a 2 years technical stop during which all magnet's ICs will have to be opened to consolidate the magnet electrical connections. The IC thermal shields will therefore have to be removed and re-installed after the work is completed. In order to eliminate the risk of fire hazard when re-welding, it has been decided to review the design of the IC shields, by replacing the welded bridges with a mechanical clamping which also preserves its thermal function. An additional advantage of this new solution is the ease in dismantling for maintenance, and eliminating weld-grinding operations at removal needing radioprotection measures because of material activation after long-term operation of the LHC. This paper describes the new design of the IC shields and in particular the theoretical and experimental validation of its thermal performance. Furthermore a status report of the on-going upgrade work in the LHC is given.

Performance assesment of pre-series beam wire scanner prototypes for the LHC injectors upgrade

CERN Document Server

AUTHOR|(CDS)2243534

The BEAM department (BE), is in charge of the development and operation of the accelerator components. Inside this department, the Beam Instrumentation group (BE-BI) works on the instruments that allows the operators and scientists to observe the accelerated beam and its characteristics. Finally, the Profile Measurement section (BE-BI-PM) deals with all the instruments capable of measuring the particles transverse distribution (often called transverse beam profile). Among the different systems developed and maintained by the section, the Beam Wire Scanners (BWS) are particularly relevant, because ensures the accurate beam profile measurements in all the circular accelerators and serves as calibration for other instruments. A total of 31 BWS are installed in the PS, PSB, SPS and LHC (see Fig. 1 to recognize the different accelerators). All of these instruments present a different design, depending on their location, and are not satisfying the HL-LHC needs. In order to harmonize the CERN’s BWS with a single d...

RAMSES stands guard over the accelerator chain

CERN Multimedia

CERN Bulletin

2010-01-01

RAMSES, the system that is used to monitor radiation at the LHC, CNGS, CTF3 and n-TOF facilities, will soon be installed at strategic points in the accelerator chain, replacing the older monitoring system ARCON. The replacement programme has already begun.   RAMSES (which stands for “Radiation Monitoring System for the Environment and Safety”) is designed to protect workers, the general public and the environment, both on the Organization’s site and in the surrounding areas. It is currently operational on all the LHC sites and at CTF3, CNGS and n-TOF, while the remaining sites are still equipped with the ARCON (Area CONtroller) system. Daniel Perrin, head of the Instrumentation and Logistics Section of the HSE Unit's Radiation Protection Group, explains: “ARCON was designed for the old LEP accelerator and dates back to the early 1980s, while RAMSES is a much more recent design intended specifically for the LHC. With 389 detectors distributed across 124 mea...

Initial Experience with the Machine Protection System for LHC

CERN Document Server

Schmidt, Ruediger; Dehning, Bernd; Ferro-Luzzi, Massimiliano; Goddard, Brennan; Lamont, Mike; Siemko, Andrzej; Uythoven, Jan; Wenninger, Jorg; Zerlauth, Markus

2010-01-01

For nominal beam parameters at 7 TeV/c each proton beam with a stored energy of 362 MJ threatens to damage accelerator equipment in case of uncontrolled beam loss. These parameters will only be reached after some years of operation, however, a small fraction of this energy is already sufficient to damage accelerator equipment or experiments. The correct functioning of the machine protection systems is vital during the different operational phases already for initial operation. When operating the complex magnet system, with and without beam, safe operation relies on the protection and interlock systems for the superconducting circuits. For safe injection and transfer of the beams from SPS to LHC, transfer line parameters are monitored, beam absorbers must be in the correct position and the LHC must be ready to accept beam. At the end of a fill and in case of failures beams must be properly extracted onto the dump blocks, for some types of failure within less than few hundred microseconds. Safe operation requir...

Cold dark matter and the LHC

International Nuclear Information System (INIS)

Battaglia, Marco; Hinchliffe, Ian; Tovey, Daniel

2004-01-01

The recent determination of the dark matter density in the universe by the WMAP satellite has brought new attention to the interplay of results from particle physics experiments at accelerators and from cosmology. In this paper we discuss the prospects for finding direct evidence for a candidate dark matter particle at the LHC and the measurements which would be crucial for testing its compatibility with the cosmology data. (topical review)

Highlights of LHC experiments – Part I

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00072301; The ATLAS collaboration

2017-01-01

The superb performance of the LHC accelerator in 2016, in both live time and peak luminosity, has provided a large data sample of collisions at 13 TeV. Excellent performances of the ATLAS and LHCb detectors, together with highly performant offline and analysis systems, mean that a wealth of results are already available from 13 TeV data. Selected highlights are reported here.

Installation of an accelerator from theory to practice

CERN Document Server

Foraz, K; Weisz, S; CERN. Geneva. TS Department

2004-01-01

The size and complexity of the LHC project at CERN calls for a strong co-ordination of all installation activities. The detailed installation planning has to take into account many constraints such as the component production rates, the installation contracts or the transport and handling requirements in a narrow tunnel with limited access points. The planning also needs to be flexible enough to cope with aleas that are unavoidable in such a large project that spans over many years. This paper describes the follow-up methodology, both in the field and in the office, adopted by the IC team to assist the groups involved in the installation of the LHC machine.

27 June 2012 - Ambassador K. Pierce, Permanent Representative of the United Kingdom of Great Britain and Northern Ireland to the United Nations Office and other international organisations in Geneva visiting the LHC tunnel at Point 5 with Department Head P. Collier and CMS control room with Former Collaboration Spokesperson J. Virdee.

CERN Multimedia

Laurent Egli

2012-01-01

27 June 2012 - Ambassador K. Pierce, Permanent Representative of the United Kingdom of Great Britain and Northern Ireland to the United Nations Office and other international organisations in Geneva visiting the LHC tunnel at Point 5 with Department Head P. Collier and CMS control room with Former Collaboration Spokesperson J. Virdee.

10 February 2012 - Permanent Representative of the Republic of India to the Conference on Disarmament, United Nations Office at Geneva Ambassador Mehta signing the guest book with International Relations Adviser R. Voss;in the LHC tunnel at Point 2 and ALICE underground experimental area with Collaboration Deputy Spokesperson Y. Schutz.

CERN Document Server

Maximilien Brice

2012-01-01

10 February 2012 - Permanent Representative of the Republic of India to the Conference on Disarmament, United Nations Office at Geneva Ambassador Mehta signing the guest book with International Relations Adviser R. Voss;in the LHC tunnel at Point 2 and ALICE underground experimental area with Collaboration Deputy Spokesperson Y. Schutz.

8 April 2013 - Indian Hon'ble Minister for Ministry of Science & Technology and Ministry of Earth Sciences Shri Sudini Jaipal Reddy in the LHC tunnel with K. Foraz, visiting the CMS cavern with Technical Coordinator A. Ball and Former Spokesperson T. Virdee, signing the guest book with Director-General R. Heuer.

CERN Multimedia

Samuel Morier-Genoud

2013-01-01

8 April 2013 - Indian Hon'ble Minister for Ministry of Science & Technology and Ministry of Earth Sciences Shri Sudini Jaipal Reddy in the LHC tunnel with K. Foraz, visiting the CMS cavern with Technical Coordinator A. Ball and Former Spokesperson T. Virdee, signing the guest book with Director-General R. Heuer.

17 January 2014 - Y. Sakurada Japanese Senior Vice Minister of Education, Culture, Sports, Science and Technology signing the Guest book with CERN Director-General R. Heuer and visiting the LHC tunnel at Point 1 with Technology Department Head J.M. Jiménez. Head of International Relations R. Voss present throughout.

CERN Multimedia

Pantelia, Anna

2014-01-01

17 January 2014 - Y. Sakurada Japanese Senior Vice Minister of Education, Culture, Sports, Science and Technology signing the Guest book with CERN Director-General R. Heuer and visiting the LHC tunnel at Point 1 with Technology Department Head J.M. Jiménez. Head of International Relations R. Voss present throughout.

CERN Open Days The LHC demystified!

CERN Multimedia

2008-01-01

Lots of surprises are being planned for the CERN Open Days scheduled for 5 and 6 April (see 21 January edition of the Bulletin). Fred’s itinerary on 6 April 20089.00 a.m\tDeparture from SM12 at CERN (the pit down which all the LHC magnets were lowered into the tunnel)9.15 a.m. Saint-Genis theatre10.00 a.m.\tRoussillon communal hall in Crozet 10.50 a.m. La Chenaille communal hall in Echenevex 11.40 a.m. CMS Building SX5 at Cessy 2.30 p.m. La Forge communal hall in Versonnex 3.30 p.m. Le Levant communal hall in Ferney Voltaire4.40 Forum in Meyrin 5.30 p.m. Main Auditorium at CERN For instance, Fred, who fronts the French television programme "C’est pas sorcier" on France 3 will be taking part in the Open Day for the general public on Sunday, 6 April. He will be on board a CERN lorry carrying a 35 tonne 15 m long dipole magnet and will make halts at eight Swiss and French communes around the LHC Ring to meet the local inhabitants (see...

20 September 2013 - Ambassador Z. Akram , Permanent Representative of the Islamic Republic of Pakistan to the United Nations Office and other international organisations in Geneva (3rd) with Mechanical and Materials Engineering Group Leader F. Bertinelli, Head of International Relations R. Voss, CMS Collaboration, Quaid-i-Azam University H. Hoorani, Permanent Mission First Secretary U. Iqbal Jadoon and LHC Consolidation, Industrial Services, Technology Department JP. Tock in front of the lift to the LHC tunnel at Point 1. Site Manager M. Décombaz on the back.

CERN Multimedia

Anna Pantelia

2013-01-01

20 September 2013 - Ambassador Z. Akram , Permanent Representative of the Islamic Republic of Pakistan to the United Nations Office and other international organisations in Geneva (3rd) with Mechanical and Materials Engineering Group Leader F. Bertinelli, Head of International Relations R. Voss, CMS Collaboration, Quaid-i-Azam University H. Hoorani, Permanent Mission First Secretary U. Iqbal Jadoon and LHC Consolidation, Industrial Services, Technology Department JP. Tock in front of the lift to the LHC tunnel at Point 1. Site Manager M. Décombaz on the back.

Review of BLM thresholds at tertiary LHC collimators

CERN Document Server

AUTHOR|(CDS)2257482; Zanetti, Marco

The Large Hadron Collider is designed to accelerate protons at the unprecedented energy of 7 TeV. With a total stored energy of 360 MJ, even tiny losses can cause machine downtime or induce damage to sensitive accelerator components. The Beam Loss Monitors (BLMs) are an important component of the complex LHC protection system. They consist of a series of ionisation chambers located all around the ring to detect secondary particle showers induced by beam losses. The monitors are assigned thresholds such that if the radiation generated by the loss is too high, the BLM triggers a beam dump, preventing the loss to grow excessively. BLM signals are recorded for different integration windows, in order to detect losses on very different time scales, ranging from the extremely short ones (taking place over half a turn) to those very close to steady state (i.e. lasting for more than a minute). The LHC is equipped with a complex collimation system, to provide the machine with passive protection in case of transient los...

An excellent performance for the non-LHC programme

CERN Multimedia

2010-01-01

With the LHC firmly in the public eye, the rest of CERN’s accelerator complex and experimental programme isn’t getting the attention it richly deserves, so I’ve decided to address that in my message this week. After all, even the LHC relies on the machines that deliver its beams day after day with little or no fanfare. It’s time for the people involved with those machines and the experiments that use them, to step forward and take their share of the limelight.   The first link in the CERN accelerator chain is Linac 2, a machine first switched on in 1978 and scheduled to be replaced by Linac 4 in 2016. It is here that most of CERN's beams are born. From there, the beams move into the booster, which combines bunches from the linac in order to boost intensity. From the booster, it’s onto the PS, and then to the SPS. All of these machines have been in service for over 30 years. Along the way, beams are farmed out to a range of experimental facilities....

Landscape of Future Accelerators at the Energy and Intensity Frontier

Energy Technology Data Exchange (ETDEWEB)

Syphers, M. J. [Northern Illinois U.; Chattopadhyay, S. [Northern Illinois U.

2016-11-21

An overview is provided of the currently envisaged landscape of charged particle accelerators at the energy and intensity frontiers to explore particle physics beyond the standard model via 1-100 TeV-scale lepton and hadron colliders and multi-Megawatt proton accelerators for short- and long- baseline neutrino experiments. The particle beam physics, associated technological challenges and progress to date for these accelerator facilities (LHC, HL-LHC, future 100 TeV p-p colliders, Tev-scale linear and circular electron-positron colliders, high intensity proton accelerator complex PIP-II for DUNE and future upgrade to PIP-III) are outlined. Potential and prospects for advanced “nonlinear dynamic techniques” at the multi-MW level intensity frontier and advanced “plasma- wakefield-based techniques” at the TeV-scale energy frontier and are also described.

LHC Report: out of the clouds (part II)

CERN Multimedia

Giovanni Rumolo for the LHC team

2015-01-01

A large fraction of the LHC beam-time over the last two weeks has been devoted to the second phase of the scrubbing of the vacuum chambers. This was aimed at reducing the formation of electron clouds in the beam pipes, this time performed with 25-nanosecond spaced bunches. This operation is designed to prepare the machine for a smooth intensity ramp-up for physics with this type of beam.   The scrubbing of the accelerator beam pipes is done by running the machine under an intense electron cloud regime while respecting beam stability constraints. When electron cloud production becomes sufficiently intense, the probability of creating secondary electrons at the chamber walls decreases and this inhibits the whole process. In this way, the scrubbing operation eventually reduces the formation of electron clouds, which would otherwise generate instabilities in the colliding beams. The second phase of LHC scrubbing started on Saturday, 25 July, when 25 ns beams were circulated again in the LHC...

Golden Hadron awards for the LHC's top suppliers.

CERN Multimedia

Maximilien Brice

2003-01-01

The following firms have been selected to receive a GOLDEN HADRON AWARD 2003, in recognition of their outstanding achievement: JDL TECHNOLOGIES, Belgium "in producing automatic cable inspection systems", FURUKAWA ELECTRIC COMPANY, Japan "in producing high quality superconducting cable", IHI Corporation, Japan, and LINDE KRYOTECHNIK, Switzerland "in producing novel 1.8 K refrigeration units based on advanced cold compressor technology" for the Large Hadron Collider.Photos 01, 02: Recipients of the 2003 Golden Hadron awards at the presentation ceremony on 16 May.Photo 03: LHC project leader Lyn Evans updates the award recipients on work for CERN's new accelerator.Photo 04: René Joannes of JDL Technologies (left) receives a Golden Hadron award from LHC project leader Lyn Evans.Shinichiro Meguro, managing director of Furukawa Electric Company, receives a Golden Hadron award from LHC project leader Lyn Evans.Photo 06: Kirkor Kurtcuoglu of Linde Kryotechnik (left) and Motoki Yoshinaga, associate director of IHI...

SUPERCONDUCTING DIPOLE MAGNETS FOR THE LHC INSERTION REGIONS

International Nuclear Information System (INIS)

WILLEN, E.; ANERELLA, M.; COZZOLINO, J.; GANETIS, G.; GHOSH, A.; GUPTA, R.; HARRISON, M.; JAIN, A.; MARONE, A.; MURATORE, J.; PLATE, S.; SCHMALZLE, J.; WANDERER, P.; WU, K.C.

2000-01-01

Dipole bending magnets are required to change the horizontal separation of the two beams in the LHC. In Intersection Regions (IR) 1, 2, 5, and 8, the beams are brought into collision for the experiments located there. In IR4, the separation of the beams is increased to accommodate the machine's particle acceleration hardware. As part of the US contribution to the LHC Project, BNL is building the required superconducting magnets. Designs have been developed featuring a single aperture cold mass in a single cryostat, two single aperture cold masses in a single cryostat, and a dual aperture cold mass in a single cryostat. All configurations feature the 80 mm diameter, 10 m long superconducting coil design used in the main bending magnets of the Relativistic Heavy Ion Collider recently completed at Brookhaven. The magnets for the LHC, to be built at Brookhaven, are described and results from the program to build two dual aperture prototypes are presented

Detector and System Developments for LHC Detector Upgrades

CERN Document Server

Mandelli, Beatrice; Guida, Roberto; Rohne, Ole; Stapnes, Steinar

2015-05-12

The future Large Hadron Collider (LHC) Physics program and the consequent improvement of the LHC accelerator performance set important challenges to all detector systems. This PhD thesis delineates the studies and strategies adopted to improve two different types of detectors: the replacement of precision trackers with ever increasingly performing silicon detectors, and the improvement of large gaseous detector systems by optimizing their gas mixtures and operation modes. Within the LHC tracker upgrade programs, the ATLAS Insertable B-layer (IBL) is the first major upgrade of a silicon-pixel detector. Indeed the overall ATLAS Pixel Detector performance is expected to degrade with the increase of luminosity and the IBL will recover the performance by adding a fourth innermost layer. The IBL Detector makes use of new pixel and front-end electronics technologies as well as a novel thermal management approach and light support and service structures. These innovations required complex developments and Quality Ass...

The ATLAS computing challenge for HL-LHC

CERN Document Server

Campana, Simone; The ATLAS collaboration

2016-01-01

The ATLAS experiment successfully commissioned a software and computing infrastructure to support the physics program during LHC Run 2. The next phases of the accelerator upgrade will present new challenges in the offline area. In particular, at High Luminosity LHC (also known as Run 4) the data taking conditions will be very demanding in terms of computing resources: between 5 and 10 KHz of event rate from the HLT to be reconstructed (and possibly further reprocessed) with an average pile-up of up to 200 events per collision and an equivalent number of simulated samples to be produced. The same parameters for the current run are lower by up to an order of magnitude. While processing and storage resources would need to scale accordingly, the funding situation allows one at best to consider a flat budget over the next few years for offline computing needs. In this paper we present a study quantifying the challenge in terms of computing resources for HL-LHC and present ideas about the possible evolution of the ...

LHC Report: First 13TeV collisions

CERN Multimedia

Jan Uythoven for the LHC team

2015-01-01

On Wednesday 20 May at around 10.30 p.m., protons collided in the LHC at the record-breaking energy of 13 TeV for the first time. These test collisions were to set up various systems and, in particular, the collimators. The tests and the technical adjustments will continue in the coming days.   The CCC was abuzz as the LHC experiments saw 13 TeV collisions.   Preparation for the first physics run at 6.5 TeV per beam has continued in the LHC. This included the set-up and verification of the machine protection systems. In addition, precise measurements of the overall focusing properties of the ring – the so-called “optics” – were performed by inducing oscillations of the bunches, and observing the response over many turns with the beam position monitors (BPM). The transverse beam size in the accelerator changes from the order of a millimetre around most of the circumference down to some tens of microns at the centre of the exper...

A slice through a prototype LHC bending magnet

CERN Multimedia

Laurent Guiraud

1998-01-01

This slice through a prototype LHC magnet clearly shows the superconducting cable in several blocks around the central hole – the beam pipe in which the LHC’s accelerated beams will travel. Magnet design is crucial to the LHC’s success and this sample is among the first to be built to the final cable configuration.

LHC Starts the Search for Sparticles in April

CERN Multimedia

2008-01-01

The long expected CERN Large Hadron Collider will become operational somewhere this spring, and physicists all around the world can hardly wait to see what new discoveries it will bring. For example, whether the LHC accelerating particles towards each other at speeds close to that of light are able to prove the supersymmetry theory or not.

Magnetic field measurements of LHC inner triplet quadrupoles fabricated at Fermilab

International Nuclear Information System (INIS)

Velev, G.V.; Bossert, R.; Carcagno, R.; DiMarco, J.; Feher, S.; Kashikhin, V.V.; Kerby, J.; Lamm, M.; Orris, D.; Schlabach, P.; Strait, J.

2006-01-01

Fermilab, as part of the US-LHC Accelerator Project, is producing superconducting low-beta quadrupole magnets for the Large Hadron Collider (LHC). These 5.5 m long magnets are designed to operate in superfluid helium at 1.9 K with a nominal gradient of 205 T/m in the 70 mm bore. Two quadrupoles separated by a dipole orbit corrector in a single cryogenic assembly comprise the Q2 optical elements of the final focus triplets in the LHC interaction regions. The field quality of the quadrupoles is measured at room temperature during construction of the cold masses as well as during cold testing of the cryogenic assembly. We summarize data from the series measurements of the magnets and discuss various topics of interest

Magnetic field measurements of LHC inner triplet quadrupoles fabricated at Fermilab

Energy Technology Data Exchange (ETDEWEB)

Velev, G.V.; Bossert, R.; Carcagno, R.; DiMarco, J.; Feher, S.; Kashikhin, V.V.; Kerby, J.; Lamm, M.; Orris, D.; Schlabach, P.; Strait, J.; /Fermilab

2006-08-01

Fermilab, as part of the US-LHC Accelerator Project, is producing superconducting low-beta quadrupole magnets for the Large Hadron Collider (LHC). These 5.5 m long magnets are designed to operate in superfluid helium at 1.9 K with a nominal gradient of 205 T/m in the 70 mm bore. Two quadrupoles separated by a dipole orbit corrector in a single cryogenic assembly comprise the Q2 optical elements of the final focus triplets in the LHC interaction regions. The field quality of the quadrupoles is measured at room temperature during construction of the cold masses as well as during cold testing of the cryogenic assembly. We summarize data from the series measurements of the magnets and discuss various topics of interest.

CERN looks to the long-term future: might a 100km circular collider follow the LHC around mid-century?

CERN Multimedia

CERN. Geneva

2015-01-01

Particle physics is a long-term field of research: the LHC was originally conceived in the 1980s, but did not start running until 25 years later. An accelerator unlike any other, it is now just at the start of a programme that is set to run for another 20 years. While the LHC programme is already well defined for the next two decades, it is now time to look even further ahead, and so CERN is initiating an exploratory study for a future long-term project centred on a next-generation circular collider with a circumference of 80 to 100 kilometres. A worthy successor to the LHC, whose collision energies will reach 13 TeV in 2015, such an accelerator would allow particle physicists to push the boundaries of knowledge even further. The Future Circular Collider (FCC) programme will focus on studies for a hadron collider, like the LHC, capable of reaching unprecedented energies in the region of 100 TeV. It will also study electron-positron and electron-proton options. Opening with an introduction to the LHC and its...

Le collisionneur LHC dans la tourmente: retard important en perspective

CERN Multimedia

Sacco, Laurent

2007-01-01

Bad news for particle physicist community: LHC, the biggest protons collider in the world, will not probably work in 2007. Supports of the superconductive magnetic quadrupoles, intended to focus the beams of protons in the accelerator, have just broken during preliminary tests. (1,5page)

The miniature accelerator

CERN Multimedia

Antonella Del Rosso

2015-01-01

The image that most people have of CERN is of its enormous accelerators and their capacity to accelerate particles to extremely high energies. But thanks to some cutting-edge studies on beam dynamics and radiofrequency technology, along with innovative construction techniques, teams at CERN have now created the first module of a brand-new accelerator, which will be just 2 metres long. The potential uses of this miniature accelerator will include deployment in hospitals for the production of medical isotopes and the treatment of cancer. It’s a real David-and-Goliath story.   Serge Mathot, in charge of the construction of the "mini-RFQ", pictured with the first of the four modules that will make up the miniature accelerator. The miniature accelerator consists of a radiofrequency quadrupole (RFQ), a component found at the start of all proton accelerator chains around the world, from the smallest to the largest. The LHC is designed to produce very high-intensity beams ...