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Crystals for High Energy Calorimetry

#2156


R&D Studies for Growing Long CeF3 Crystals to be used on Calorimetry in the E391a Experiment (KEK, Japan)

Tech Area / Field

  • CHE-IND/Industrial Chemistry and Chemical Process Engineering/Chemistry
  • MAT-SYN/Materials Synthesis and Processing/Materials

Status
3 Approved without Funding

Registration date
29.03.2001

Leading Institute
VNIIKhT (Chemical Technology), Russia, Moscow

Supporting institutes

  • Institute of General Physics named after A.M. Prokhorov RAS / Laser Materials and Technology Research Center, Russia, Moscow\nITEF (ITEP), Russia, Moscow\nJoint Institute of Nuclear Research, Russia, Moscow reg., Dubna

Collaborators

  • KEK, Japan, Tsukuba\nOsaka University / Research Center for Nuclear Physics, Japan, Osaka

Project summary

This Project is a result of the joint effort of four institutes: All-Russian Research Institute of Chemical Technology (ARRICT), the State Scientific Center "Institute for Theoretical and Experimental Physics" (ITEP), Joint Institute for Nuclear Research (JINR) and Scientific Center of Laser Materials and Technology of General Physics Institute (SC LMT, GPI RAS) on the basis of their technological and scientific potential.

The final goal of our project is the construction of downstream electromagnetic calorimeter (EM) for E391a experiment at High Energy Accelerator Research Organization (KEK). The experiment E391a is aimed to detect the rare K0L® p0nn decay. The K0L® p0nn decay is one of important processes which are desired an experimental study within the decade. The standard model (SM) predicts the K0L p0nn branching ratio to be around 3×10-11. Since the present experimental upper limit is 5.9×10-7, it is quite challenging to jump off a high sensitivity experiment which aims for a branching ratio measurement of few % by an observation of hundreds of SM events.

The project includes research and development of a technology of CeF3 single crystal growing. The main detector of the E391a experimental set-up, the downstream electromagnetic calorimeter, is planned to be made of 3,000 CeF3 single crystals. A new crystal, CeF3, is one of the heavy and fast scintillators suitable for various high-energy physics experiments and potentially for general purpose radiation detector. Many attempts have been carried out to grow long CeF3 crystals. However, long CeF3 crystals having the same properties as those of short samples have not yet been stably grown. Our Japanese Collaborators have an experience in CeF3 crystal growing technology. Within the present project the collaborating staff plan to develop the method of mass production of long CeF3 single crystal. We plan to produce about 100 single crystals each of size 2.5×2.5×34 cm3 (200 kg) in ARRICT in Russia, but in future we will produce 1500 crystals for the E391a experiment purpose. This is the half amount of crystals needed for experiment. 100 and 1,500 single crystals will be paid by separate contract with KEK.

The large uniform CeF3 crystal production will be based on the experience of scientists of ARRICT and GPI RAS in original technology of synthesis of polycrystalline high purity (99.999%) anhydrous CeF3 powder production. As a result of the project performance the following valuable scientific and engineering problems will be solved:

1. The growth technology of large (2.5×2.5×34) cm3 optically uniform single crystals of CeF3 using directional crystallization method will be developed.

2. The methods of quality control of the grown CeF3 single crystals will be developed. It will be based on modern physical methods of investigations including electron and X-ray techniques of crystal structure study, absorption, fluorescent and kinetic spectral analysis.

3. The experimental series of large CeF3 single crystals with stable and controlled parameters will be produced at first time in the world.

The work plan will be carried out in the following way: ARRICT and SC LMT GPI RAS are responsible for CeF3 growing and large crystal mass production technology development. ITEP and JINT staff is responsible for crystal purity testing and characteristics measurement. JINR is responsible for testing produced crystals, delivering to KEK, and beam test at KEK. JINR also will participate at crystal growing technology development with ARRICT institute. The JINR also will participate in discussions on organizational matter, coordination the project carry out and information interchange between cooperating Parties.


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