Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userMuon capture reaction on $^{100}Mo$ to study nuclear responses for double beta decays and astro-neutrinos
224
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
The negative-muon capture reaction (MCR) on the enriched $^{100}Mo$ isotope was studied for the first time to investigate neutrino nuclear response for neutrino-less double beta decays and supernova neutrino nuclear interactions. MCR on $^{100}Mo$ proceeds mainly as $^{100}Mo(mu,xn)^{100-x}Nb$ with $x$ being the number of neutrons emitted from MCR. The Nb isotope mass distribution was obtained by measuring delayed gamma-rays from radioactive $^{100-x}Nb$. By using the neutron emission model after MCR, the neutrino response (the strength distribution) for MCR was derived. Giant resonance (GR)-like distribution at the peak energy around 11-14 MeV, suggests concentration of the MCR strength at the muon capture GR region.
rate research
Read More
The isotope $ {}^{99} rm{Mo} $, the generator of $ {}^{99m} rm{Tc} $ used for diagnostic imaging, is supplied by extracting from fission fragments of highly enriched uranium in reactors. However, a reactor-free production method of $ {}^{99} rm{Mo} $ is searched over the world from the point of view of nuclear proliferation. Recently, $ {}^{99} rm{Mo} $ production through a muon capture reaction was proposed and it was found that about $ 50 , % $ of $ {}^{100} rm{Mo} $ turned into $ {}^{99} rm{Mo} $ through $ {}^{100} rm{Mo} left( mu^-, n right) $ reaction [arXiv:1908.08166]. However, the detailed physical process of the muon capture reaction is not completely understood. We, therefore, study the muon capture reaction of $ ^{100} rm{Mo} $ by a theoretical approach. We used the proton-neutron QRPA to calculate the muon capture rate. The muon wave function is calculated with considering the electronic distribution of the atom and the nuclear charge distribution. The particle evaporation process from the daughter nucleus is calculated by a statistical model. From the model calculation, about $ 38 , % $ of $ {}^{100} rm{Mo} $ is converted to $ {}^{99} rm{Mo} $ through the muon capture reaction, which is in a reasonable agreement with the experimental data. It is revealed that negative parity states, especially $ 1^- $ state, play an important role in $ {}^{100} rm{Mo} left( mu^-, n right) {}^{99} rm{Nb} $. The feasibility of $ {}^{99} rm{Mo} $ production by the muon capture reaction is also discussed. Isotope production by the muon capture reaction strongly depends on the nuclear structure.
We present a measurement of the electron-capture branch of $^{100}$Tc. Our value, $B(text{EC}) = (2.6 pm 0.4) times 10^{-5}$, implies that the $^{100}$Mo neutrino absorption cross section to the ground state of $^{100}$Tc is roughly one third larger than previously thought. Compared to previous measurements, our value of $B(text{EC})$ prevents a smaller disagreement with QRPA calculations relevant to double-$beta$ decay matrix elements.
The CUPID-Mo experiment at the Laboratoire Souterrain de Modane (France) is a demonstrator for CUPID, the next-generation ton-scale cryogenic $0 ubetabeta$ experiment. It consists of a 4.2 kg array of 20 enriched Li$_{2}$$^{100}$MoO$_4$ scintillating bolometers to search for the lepton number violating process of $0 ubetabeta$ decay in $^{100}$Mo. With more than one year of operation (2.16 kg$times$yr of physics data), no event in the region of interest and hence no evidence for $0 ubetabeta$ is observed. We report a new limit on the half-life of $0 ubetabeta$ decay in $^{100}$Mo of $T_{1/2} > 1.5 times 10^{24},$yr at 90 % C.I. The limit corresponds to an effective Majorana neutrino mass $langle m_{betabeta} rangle$ $<$ (0.31--0.54)$,$eV, dependent on the nuclear matrix element in the light Majorana neutrino exchange interpretation.
Muon capture isotope production (MuCIP) using negative ordinary muon capture reactions (OMC) is used to efficiently produce various kinds of nuclear isotopes for both fundamental and applied science studies. The large capture probability of muon into a nucleus, together with the high intensity muon beam, make it possible to produce nuclear isotopes in the order of 10^{9-10} per second depending on the muon beam intensity. Radioactive isotopes (RIs) produced by MuCIP are complementary to those produced by photon and neutron capture reactions and are used for various science and technology applications. MuCIP on ^{Nat}Mo by using the RCNP MuSIC muon beam is presented to demonstrate the feasibility of MuCIP. Nuclear isotopes produced by MuCIP are evaluated by using a pre-equilibrium (PEQ) and equilibrium (EQ) proton neutron emission model. Radioactive $^{99}$Mo isotopes and the metastable ^{99m}Tc isotopes, which are used extensively in medical science, are produced by MuCIP on ^{Nat}Mo and ^{100}Mo.
Energy resolution, alpha/beta ratio, pulse-shape discrimination for gamma rays and alpha particles, temperature dependence of scintillation properties, and radioactive contamination were studied with CaMoO4 crystal scintillators. A high sensitivity experiment to search for neutrinoless double beta decay of 100-Mo by using CaMoO4 scintillators is discussed.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
