Neodymium Isotopes Separation
Neodymium Isotopes Separation for Searching the Neutrino Mass (2-beta-0-nu-decay of Nd-150)
Tech Area / Field
- FIR-ISO/Isotopes/Fission Reactors
- PHY-PFA/Particles, Fields and Accelerator Physics/Physics
3 Approved without Funding
Kurchatov Research Center, Russia, Moscow
- ITEF (ITEP), Russia, Moscow
- KEK, Japan, Tsukuba\nKorea Atomic Energy Research Institute (KAERI), Korea, Yuseong\nUniversite catholique de Louvain/Institut de physique nucleaire, Belgium, Louvain-la-Neuve\nLawrence Livermore National Laboratory, USA, CA, Livermore
Project summaryThe aim of the project is to search for neutrinoless double b-decay forbidden by the lepton number conservation law. This task pertains to the most important and fundamental aspects of physics, which lie beyond the Standard Model, and potentially allows to answer the question about the nature of the neutrino particle. Neutrinoless double b-decay, if it exists, requires neutrinos to be Majorana particles (neutrinos are identical with antineutrinos), the lepton number conservation law to be violated, and also requires that at least a neutrino of one type has a mass.
The first evidence for neutrinoless double b-decay of 76Ge and for nonzero neutrino mass has appeared now (H.V. Klapdor-Kleingrothaus et al., Modern Physics Letters A, Vol.16, No. 37 (2001) 2409-2420). The search for 2b0n-decay by the track method using 150Nd isotopes becomes more actual.
At present time a new generation universal detector for double b-decay search has put into operation at the Institute for Theoretical and Experimental Physics (ITEP). The main part of the setup is the Time Projection Chamber (TPC) of volume 13m3 placed in magnetic field (the solenoidal magnet is 5.5 m in diameter). Up to 10 kg of isotopes to be investigated can be put into the TPC as a source and they can be both in the gas and in the solid states. The discovery potential of neutrinoless double b-decay experiments depends on a special class of isotopes for which the cascades of regular b-decays are forbidden by conservation laws. There are only 35 isotopes, candidates for 2b-decay search. Among them the rare-earth isotope 150Nd is the most advantageous, it has a high transition energy and high Coulomb factor. To reduce background a 150Nd-sample maximally enriched is needed for double b-decay experiments, while the natural abundance of this isotope is 5.6%.
A group of weapon scientists from the Russian Research Centre "Kurchatov Institute" (RRC KI) develops the technology of laser isotope separation, which is capable also for separation of neodymium isotopes. The main advantage of this technology vs. traditional isotope separation methods is it does not employ the gas phase of working materials. Rare earth elements are not found in the gas phase under normal conditions.
The laser isotope separation technology was originally proposed in the USSR for fissile isotope separation. The best results has been obtained to date in Lawrence Livermore National Laboratory (USA), where a large-scale setup is used for uranium enrichment.
16 weapon scientists and engineers from RRC KI will participate in this project and spend 272 person-months to fulfill it.
Industrial and commercial potential applications of the laser isotope separation technology include producing large amount of stable isotopes for medicine, industry, and reactor fuel reprocessing. A very important application of this technology is production of 157Gd isotope, which is used as a burning component of reactor fuel at nuclear power stations. Being admixed to fuel, 157Gd increases the lifetime by a factor 1.5-2.0 and permits to change fuel not so often, which in its turn decreases the probability of an accident and radiation damage during fuel replacement and also decreases the produced energy cost.