The Compact Muon Solenoid Experiment at the LHC
Images of Assembly and Installation
Contents 1. 2. 3. 4.
Compact Muon Solenoid
Civil Engineering Assembly in the Surface Building Lowering of the Heavy Elements Installing and Connecting the CMS Detector in the Underground Experiment Cavern s
Pages 8 to 13 Pages 14 to 35 Pages 36 to 45 Pages 46 to 64
Aerial view of the CERN site. The schematic shows the position of the accelerator tunnel, located 100m underground, and the relative position of the CMS experiment.
Foreword The images in this book illustrate the assembly, installation and commissioning of the CMS detector. They cover the activities at Point 5 in Cessy, France, between 1998 and 2008. CMS is one of the most complex scientific instruments ever built. It has taken about 20 years to go from conceptual design to the completion of construction of the CMS detector for the LHC start-up in September 2008. Accomplishing this has required the talents, efforts and resources of over 2500 scientists and engineers from about 180 institutions in 38 countries. Numerous technical, industrial and financial challenges were successfully overcome. The detector is performing well and fulfilling the specifications set out in the Technical Design Reports submitted some ten years ago. The book is dedicated to all of the many people, including their funding agencies, who have contributed to the successful construction of CMS. Tejinder S. Virdee CMS Spokesperson
http://cms.cern.ch/
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| Civil Engineering | Point 5 in Cessy
Aerial view of the Point 5 site in 1998 (left). The foundations of a Roman farm from the 4th century AD can be seen top-centre. Roman coins (bottom) minted in Ostia, London and Lyon between 309 and 315 AD found during archeological excavations at Point 5 (top). Aerial view of point 5 in 2000 (facing page). The large surface building and the main experiment shaft can be clearly seen. A smaller shaft to the left of the main shaft can just be seen.
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| Civil Engineering | Excavation
Fast flowing underground water made the excavation of the shaft of the CMS cavern very difficult. Liquid nitrogen, supplied via a ring of pipes (top), was used to create a cylinder of ice inside which the shaft was excavated (bottom and right) and lined with concrete. The facing page shows the floor of the experiment cavern under construction; the accelerator tunnel can be seen in top-centre.
10 | Civil Engineering | Excavation
The underground experiment cavern nearing completion (left). Inauguration of the CMS cavern in early 2005 (right). The start of the installation of the infrastructure in the experiment cavern (facing page).
12 | Views of the CMS experiment partially ‘open’
14 | Assembly on the Surface | The Magnet Iron Yoke
The assembly of the iron magnet yoke: the first of five barrel ‘wheels’ with the ‘ferris wheel’ holding structure in grey (left), the first disk of the endcap being assembled (top and bottom), the completed yoke structure in 2002 (facing page).
16 | Assembly on the Surface | The Solenoid Magnet
The assembly of the solenoid magnet. A cut of a prototype showing the structure of the superconducting coil (top), the assembled coil being rotated for insertion into the outer vacuum tank (right), the insertion of the inner vacuum tank into the coil (bottom). The completed solenoid inside the vacuum tank in 2005 (facing page).
18 | Assembly on the Surface | The Barrel Muon Chambers
Installation of a barrel muon drift tube (DT) chamber (left), pipework for the gas distribution of the chambers (top), view of inner face of one of the yoke wheels housing the DT chambers (bottom), the outer face (facing page) showing the solenoid coil, the barrel hadron calorimeter, two ECAL supermodules and the tracker tube prior to the surface test of the solenoid and parts of the experiment (autumn 2006) the latter using cosmic rays.
20 | Assembly on the Surface | The Endcap Muon Chambers
Installation of an endcap Cathode Strip Chamber (CSC) (left), Resistive Plate Chambers (RPC) installed on one of the yoke disks (top), detail of the layout during the mounting of CSC and RPC on the first endcap yoke disk (bottom), the first yoke endcap disk ready for lowering (facing page).
22 | Assembly on the Surface | The Endcap Hadron Calorimeter
Workers in Murmansk sitting on brass casings of some decommissioned shells of the Russian Northern fleet (left), the casings being melted in St Petersburg (top) and turned into raw brass plates (bottom). These were machined in Minsk and were mounted (facing page) in Point 5 to become the absorber for the endcap hadron calorimeter.
24 | Assembly on the Surface | The Barrel and Forward Hadron Calorimeter
Quartz fibres being inserted into the steel absorber of the Forward Hadron (HF) calorimeter (left), the wedges of HF with fibres and photomultiplier housings (top), one of the HF ready for lowering into the experiment cavern (bottom), one half of the barrel hadron calorimeter in the surface experiment hall (facing page).
26 | Assembly on the Surface | The Lead Tungstate Crystals and the Electromagnetic Calorimeter
A freshly grown ingot of lead tungstate (left), bare lead tungstate crystals after machining and polishing (top), a ‘module’ of about 400 crystals in their glass-fibre alveolae (bottom), preparing to measure the optical and mechanical dimensions of crystals (facing page top), a ‘supermodule’ dressed with front-end electronics (facing page bottom).
28 | Assembly on the Surface | The Endcap Electromagnetic Calorimeter
The preshower - one of eight absorber plates with silicon sensors mounted (top), the crystals mounted on one of four ‘Dees’ of the endcap electromagnetic calorimeter (top right), working in parallel on all four Dees (bottom left), the rear face of the ‘dee’ in the course of the installation of front-end electronics (bottom right), front view showing crystals of a completed “Dee” (facing page).
30 | Assembly on the Surface | The Silicon Strip Tracker
One gantry used for automatic assembly of silicon strip modules (top left), one ‘shell’ of the tracker inner barrel (TIB) with silicon modules mounted (top right), the completed assembly of four layers of the TIB (bottom left), silicon modules (bottom right), the barrel part of the silicon strip tracker (facing page). The inner tracker contains over 200 m2 of silicon strip sensors.
32 | Assembly on the Surface | The Endcap Silicon Strip Tracker and the Pixels Detector
One of the disks of the tracker endcap (TEC) with petals containing the silicon modules (left), the complex cabling on the supply tube of the barrel pixels detector (top), a view of the endcap pixels detector (bottom), a view of the completed barrel pixels detector before integration into the supply tube (facing page). The outer diameter is about 20 cm.
34 | The Experiment Cavern
Schematics of the layout of the shaft and the underground caverns (left), the test of the foam fire-extinguishing system in the experiment cavern (right). A view of the experiment in the underground cavern (facing page).
36 | The Lowering of the Heavy Elements
A view of the gantry crane for lowering of heavy elements (top). It was erected over the outside of the surface assembly hall. Closeup of the crane (right). The view of the main shaft from the floor of the experiment cavern (bottom). The lowering in November 2006 of the second heavy element of CMS (Hadron Forward Calorimeter, HF). The other HF can be seen already in the cavern.
38 | The Lowering of the Heavy Elements
Three views of the lowering of the Hadron Forward calorimeter (HF).
40 | The Lowering of the Heavy Elements
The lowering of the YE1 endcap disk (January 2007) (left). The start of the lowering of one of the barrel yoke wheels (right). Reflective targets on one of the barrel yoke wheels used for photogrammetry measurements (facing page).
42 | The Lowering of the Central and Heaviest Element
The lowering of the heaviest (1920 tonnes) and central element of CMS (YB0) containing the central wheel and the solenoid magnet. At the start (top and right), nearing the end (bottom and facing page) of a 12 hour slow descent in February 2007.
44 | The Installation of Barrel Electromagnetic Calorimeter
The installation of the barrel electromagnetic calorimeter ‘supermodules’ (SM) (top). The second SM being installed (bottom), one half barrel installed (right), all the 36 SMs of the full barrel (facing page). The barrel ECAL contains 61200 lead tungstate crystals.
46 | The Installation of the Barrel Hadron Calorimeter
Views of the installation of the barrel hadron calorimeter.
48 |The Installation of Services for the Subdetectors Situated Inside the Solenoid
The installation of the services (cables, optical fibres and cooling pipes) for the sub-detector elements installed in the solenoid: the barrel hadron and electromagnetic calorimeters and the inner tracker. Part of the team responsible for the laying of the services (top), the detail of some services (right), and after the completion of the installation of the services (facing page).
50 | The Installation of the Silicon Strip Tracker
The installation of the inner tracker. The lowering of the cylinder containing the silicon strip tracker (top and bottom), the tracker almost inserted inside the ECAL (facing page), the view of the experiment after the installation the tracker showing the barrel calorimeters already installed in the solenoid (right).
52 | The Installation of the Beam Pipe and Endcap Electromagnetic Calorimeter
The installation of the beam pipe (top, bottom and facing page). The installation of the second Dee of the endcap crystals ECAL (right).
54 | The Installation of the Pixels Detector
Installation of the barrel pixels detector (top and facing page) and the forward pixels detector (bottom left and right).
56 | The Closure of CMS
The final closure of the experiment. YE-1 ‘nose’ being inserted into the solenoid (left). Views of the final closure on the 3rd September 2008 (top, bottom and facing page).
58 | The Underground Services Cavern and the CMS Control Room
View of the off-detector electronics housed in two floors of the underground services cavern (top, right). A view of the online computing facilities housed on the upper floor of the CMS control room building (bottom). Members of the CMS Collaboration present at Point 5 in September 2008 to mark the completion of the LHC start-up detector (facing page).
60 | Visits and People
The first CMS Spokesperson and Technical Coordinator of CMS Michel Della Negra and Alain Herve respectively (top left). One of many impromptu celebrations marking an important milestone (bottom left). A view of the CMS control room in Cessy at the time of the first beam on 10 September 2008 (bottom right). The dignitaries from the local Cessy town hall visiting CMS during the Open Day in April 2008 (facing page left).
Three of many distinguished visitors to CMS: (right) UN Secretary General Ban Ki-moon being greeted by the CMS Technical Coordinator Austin Ball, as CERN Director-General Robert Aymar and CERN Deputy Director-General and Chief Scientific Officer Jos Engelen and CMS Spokesperson Tejinder Virdee look on. Tejinder Virdee describing the experiment to Stephen Hawking (facing page top right), and with Peter Higgs (facing page bottom right).
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Compiled by S. Cittolin, F. Marcastel and T. S. Virdee. Photos by S. Boreham, M. Brice, P. Ginter, C. Marcelloni and Members of the CMS Collaboration.