At the end of May, according to the results of consideration of project design documentation and results of engineering surveys, Glavgosexpertiza of Russia has issued a favourable conclusion for the construction of a new experimental hall for the U-400R cyclotron at the JINR site.

Chief Engineer of the Laboratory of Nuclear Reactions JINR Igor Kalagin comments why this hall is necessary and the way it will be made.

Igor Vladimirovich Kalagin

– Igor Vladimirovich, the U-400R is a modernised U-400 cyclotron. How will the modernisation of the U-400 take place? What are the purposes of it?

– The reconstruction of the U-400 into the U-400R, the beginning of which is scheduled for 2023, will improve the quality and intensity of accelerated beams of particles in the cyclotron, will ensure an opportunity for smooth energy variation, as well as reduce the energy consumption of the main magnet. All this will allow continuing studies at the Laboratory of Nuclear Reactions on mechanisms of nuclear reactions with beams of stable and radioactive ions in a wide energy range: from subbarrier to several dozens of MeV/nucleon.

Let me remind you that the U-400 cyclotron was created in 1978. The annual operation of the machine to ensure physical experiments and applied tasks is more than 5,600 hours. Ion beams of the U-400 were used mainly to conduct research on the synthesis and spectroscopy of SHE (ions of elements ⁴⁸Ca, ⁵⁰Ti with the energies of 5-6 MeV/nucleon) and testing of electronic components for Roscosmos.

U-400 cyclotron.

– And what is the goal of the new experimental building approved by Glavgosexpertiza?

– FLNR will construct new experimental facilities at beams of accelerated heavy ions that come through the ion pipeline system from the U-400R cyclotron. This requires the construction of the new four-storey experimental hall. This will allow expanding the FLNR experimental area by 1,000 square metres. The building of the experimental hall will be located near the building of the U-400R cyclotron and adjusted to it by the gallery with the ion pipeline.

The solutions for the protection of the building of the experimental hall are based on the principle of the defence in depth, which combines both static and dynamic barriers, as well as systems for controlling their integrity. New experimental physical facilities will be placed in three radio-isolated cabins of the new experimental hall thus allowing preparation of other facilities for the experiment during a beam run at one of the facilities. Not only new physical facilities and three big cabins pose requirements for the size of the hall but also technological systems, such as power sources, electrical panel, ventilation and special ventilation with filtration systems, sanitary locks, water cooling system, special sewerage, rooms for the temporary storage of solid and liquid radioactive waste. Moreover, there should be offices for the staff and measuring rooms of physical setups. All this determines the size and the number of floors of the building, which is, in fact, autonomous.

– Tell us, please, how was the assessment held?

– Passing the assessment is a task of the designing organization. A set of documents submitted to Glavgosexpertiza – and it includes several volumes, – experts form a set of comments that should be answered in a short time. A part of answers – about the design of the building mainly – is given by the designing organization, the other set of answers on technologies, parameters of ion beams, etc. is given by the customer – JINR, in particular, FLNR, the Capital Construction Department of the Institute. There were plenty of questions, but we tried to provide reasoned answers.

– So, the favourable conclusion from Glavgosexpertiza is received, what’s next?

– After passing Glavgosexpertiza of Russia, the design organization OOO Specatomcervice has started drafting the detailed design for the building of the experimental hall. At the end of 2021, it is planned to hold a competition to select a general constructor and start the construction. The estimated time necessary for the construction of the new experimental hall of the U-400R is 2.5 years.

Sketch of the new experimental hall of the U-400R.

– Is there anything else new in the Laboratory?

– Yes, another task of FLNR was to build a new assembly hall for the assembly and testing of new accelerators and physical facilities. And this year, the construction of this object has been completed. Areas of the FLNR assembly hall are used for the creation of experimental stands where new facilities will be assembled and commissioned. OOO Specatomcervice has developed the project of the building. The construction of the new assembly hall was completed by OOO Stroy East Invest in May 2021. Nowadays, the delivery-take-over process is underway.

New FLNR assembly hall.