L.I. Ponomarev

The new methods of description of mesic atom collisions

Two new methods are presented: (1) the adiabatic hyperspherical approach (AHSA) as applied to description of the low energy (S-wave) scattering of the mesic atoms in the ground states and (2) adiabatic complex plane method (ACPM) as applied to the description of the hydrogen isotope mesic atom scattering in the excited states.

Review of the μCF Theory after EXAT-98

A review of the Muon Catalyzed Fusion theory after the International Symposium EXAT-98 is presented. The main results obtained are discussed. Special attention is paid to the unsolved problems of the μCF phenomenon and its applications.

THE LOCAL CHARACTERISTICS OF THE BOUND STATES OF MUONIC MOLECULES

The sticking probabilitiesΩJv,G- andγ-factors for all bound states of mesic molecules ppµ, pdµ, ptµ, ddµ, dtµ, and ttµ withJ=0 andv=0, 1 have been calculated in the adiabatic hyperspherical approach (AHSA).

A 14-MeV Intense Neutron Source Based on Muon-Catalyzed Fusion - I: An Advanced Design

The results of the design study of an advanced scheme for the 14-MeV intense neutron source based on muon-catalyzed fusion (μCF) are presented. A pion production target (liquid lithium) and a synthesizer [liquid deuterium-tritium (D-T) mixture] are considered. Negative pions are produced inside a 17/7 T magnetic field by an intense (2-GeV,12-mA) deuteron beam interacting with the 150-cm-long, 0.75-cm-radius lithium target. Muons from the pion decay are collected in the backward direction and stopped in the D-T mixture of the synthesizer. The synthesizer has the shape of a 10-cm-radius sphere surrounded by two 0.03-cm-thick titanium shells. At 100 μCF events/muon, it can produce up to 1017n/s of 14-MeV neutrons. A quasi-isotropic neutron flux up to 1014 n/cm2·s-1 can be achieved in the test volume of ~2.5 l with an irradiated surface of ~350 cm2. The thermophysical and thermomechanical analyses show that the technological limits are not exceeded.

Final results on the mu He-3-capture experiment and perspectives for mu p-capture studies

Muon capture on hydrogen gives a unique possibility for a measurement of the pseudo-scalar form factor gp(qc2 = -0.88 mμ2) of the nucleonic weak current, thus providing a sensitive test of the QCD chiral symmetry perturbation theory which predicts the value of this form factor with a precision of Δgp/gp≃ 2%. For adequate comparison with theory, the muon capture rate Λc should be measured with a precision of ΔΛc/Λc ≤ 1%, that is an order of magnitude better than the precision of the present world data. We report on the project of an experiment designed to provide the required precision. Also, we present the final result of our previous experiment on a high precision measurement of the μ3He capture rate and compare this result with the PCAC prediction.

Nuclear fusion rates from resonant states of 3Hedμ molecular ion

We present new theoretical calculations of nuclear fusion rates λfJ from the resonant states of the muonic molecular ion 3Hedμ++ with total angular momenta J=0,1. As a byproduct, new very accurate variational wave functions for these states have been obtained. Using these wave functions, the probability density |Ψ(R=0)|2 in a fusion region has been calculated by extrapolating the variational solution to small internuclear distances by means of the multi-channel adiabatic solution. Calculated fusion rates for the states J=0 and J=1 are: λf0=1.9·105s-1 and λf1=0.65·103s-1, respectively.

μCF based 14 MeV intense neutron source

Results of a design study for an advanced scheme of a μCF based 14 MeV intense neutron source for test material irradiation including the liquid lithium primary target and a low temperature liquid deuterium-tritium (D–T) mixture as a secondary target are presented. According to this scheme negative pions are produced inside a 150-cm-long 0.75-cm-radius lithium target. Pions and muons resulting from the pion decay in flight are collected in the backward direction and stopped in the D–T mixture. The fusion chamber has the shape of a 10-cm-radius sphere surrounded by two 0.03-cm-thickness titanium shells. Assuming 100 fusions per muon in this scheme one can produce 14-MeV neutrons with a source strength up to 1017 n/s. A neutron flux of up to 1014 n/cm2/s can be achieved in a test volume of about 2.5 l and on the surface of about 350 cm2. The results of the thermophysical and thermomechanical analysis show that the technological limits are not exceeded. This source has the advantage of producing the original 14 MeV fusion spectrum without tails, isotropically into a 4π solid angle, contrary to the d-Li stripping neutron source.

Reduced adiabatic hyperspherical basis in the Coulomb three-body bound state problem

A new version of the adiabatic hyperspherical approach (AHSA) is suggested which has significant advantages for the calculation of three-body states with total angular momentumJ> 0. The binding energies of all bound states of mesic molecules with normal parity are calculated by the suggested method. Comparison with results of variational calculations and the fast convergence of the method confirm its high efficiency.

Calculation of equilibrium composition and establishing time in a mixture of three hydrogen isotopes

A mathematical model describing the kinetics of establishing equilibrium is developed. Equilibrium concentrations of isotopic molecules for gas mixtures used in muon catalyzed fusion research are calculated.

Muon transfer rates in collisions of hydrogen isotope mesic atoms on “bare” nuclei. Multichannel adiabatic approach

A numerical scheme for solving the problem of slow collisions in the three-body adiabatic approach is applied for calculation of muon transfer rates in collisions of hydrogen isotope atoms on bare nuclei. It is demonstrated that the multichannel adiabatic approach allows to reach high accuracy results (∼3%) estimating the cross sections of charge transfer processes which are the best ones up to the present time. The method is applicable in a wide range of energies (0.001–50 eV) which is of interest for analysis of muon catalysed fusion experiments.