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Calorimeter for Linear Сolliders

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R&D Studies of Calorimeters for Linear Сolliders

Tech Area / Field

  • PHY-PFA/Particles, Fields and Accelerator Physics/Physics
  • CHE-IND/Industrial Chemistry and Chemical Process Engineering/Chemistry
  • MAT-SYN/Materials Synthesis and Processing/Materials

Status
3 Approved without Funding

Registration date
12.02.2004

Leading Institute
Joint Institute of Nuclear Research, Russia, Moscow reg., Dubna

Supporting institutes

  • VNIIEF, Russia, N. Novgorod reg., Sarov

Collaborators

  • High Energy Accelerator Research Organization, Japan, Tsukuba\nHigh Energy Accelerator Research Organization / Institute of Particle and Nuclear Studies, Japan, Tsukuba\nShinshu University / Japanese Linear Collider Calorimeter Group, Japan, Nagano

Project summary

This Project is a result of the joint efforts of two institutes: Joint Institute for Nuclear Research (JINR) and All-Russia Research Institute of Experimental Physics (VNIIEF) on the basis of their technological and scientific potential.

The final goal of our project is the construction of Electromagnetic (EM) and Hadron calorimeter (HAD) for LC (Electron-Positron Linear Collider Project) detector at High Energy Accelerator Research Organization (KEK). One of the most important physics to study at LC is the precision study of Higgs boson. As for the Higgs mass, we now have an indirect measurement, Mh < 215 GeV at the 95% confidence level, from experiments at LEP and SLC with energy range 300-400 GeV in the center of mass and luminosity of 5×1032 cm-2sec-1. But this is not enough for precision studies for that at least 5×1033 cm-2sec-1 luminosity is needed This statement being valid, LC will be able to reach a luminosity of up to 1.5×1034 cm-2sec-1 to be Higgs/Top/W/Z/ factory and cover an energy range of 250 < Ecm < 500 GeV.

The main part of LC detector is calorimeters. The project includes research and development of technology of scintillator production, technology of reflection coating and study of calorimeter modules for the LC detector. The calorimeter will play an essential role due to the importance of energy measurement and lepton identification. Lead/plastic scintillator of tile/fiber type calorimeter and lead/plastic scintillator sampling type calorimeter were considered. Such kind of calorimeters have fast signals (rate capability), good optical characteristics (Attenuation length of a few metres allows signal transmission over relatively long distances), good mechanical properties, suitable for various high-energy physics experiments and small cost. Within the present project we plan to use in calorimeter module the scintillators produced in Russia.

For the scintillation plate production we are going to use the moulding, extrusion and raw material machining methods. Very important point of the project is to find best resolution/cost ratio having in mind full scale calorimeter.

The main advantages of the moulding and extrusion technology are minimum processing cost, practical absence of limitations on the length and width of obtained articles and universality in terms of producing on the same equipment articles of different profiles and cross-sections.

Machining may give the samples of very high quality with one reservation – one has to look for the way to make it significantly cheaper.

There exist good experience in JINR and relations with another institutions in the field of scintillator production by the methods indicated above.

Good reflection coating is strongly necessary for effective light collection of plastic scintillators. The coating is made by the way of a special chemical etching of the scintillator surface. The etching results in formation of a thin white porous layer (50-100 µm) with a high coefficient for diffusive reflection. This layer is possessed of good adhesion to the scintillator surface and allows one to glue construction materials without deterioration of its reflection properties. The light collection in the counters covered by this method was shown to be not worse than in ones using the synthetic paper TYVEK. The chemical etching makes it possible to mechanize the covering process and to reduce expenditures of labor comparing the case when counters are manually wrapped by a light reflecting material.

As a result of the project execution the following valuable scientific and engineering problems will be solved:


1. The production and reflection coating technology method of scintillators will be developed.
2. Energy resolution of calorimeter module will be developed.
3. Calorimeter modules with improved energy resolution will be developed.

The work plan will be carried out in the following way: JINR is responsible for production technology development, mass production technology development, testing and characteristics measurement. JINR, also is responsible for delivering the items to KEK and participating in assembling calorimeter modules and beam test at KEK. JINR will also participate in discussions on organizational matter, coordination of the project execution and information interchange between cooperating Parties. VNIIEF is responsible for preparation moulding dies for plastic scintillator manufacturing and looking for the ways allowing one to make the machining method as cheap as possible.


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