2 coinc idence with the chemical potential of the metal. As a resu lt, the state of the system suffer strong degeneracy, and t he density of states on the energy of the NS sample exper iences resonance spikes [9]. This contributes signif- icant ly to the magnetic moment and causes a reentrant effect. Note that in [9] the calculation was performed for orbita l susceptibility. In [6] the explanation involves the spin ( Pauli) susceptibility of the system. In this study we calculated the free energy of the NS struct ure and its magnetic moment (current of magneti- zatio n) in the magnetic field. An approximate analytical calcu lation was supplemented with a numerical one based on th e exact spectrum of Andreev levels [12] in the NS conta ct. Our approach is not based on application of the Eilen berger equation. We calculate the thermodynamic poten tial to obtain the magnetic moment. Co nsider a superconducting cylinder with the radius R wh ich is concentrically embedded with a thin layer d of a pure normal metal. The structure is placed in a magn etic field ⃗ H (0 , 0 , H) oriented along the symmetry axis o f the structure. It is assumed that the field is weak to the extent that the effect of twisting of quasiparticle trajec tories becomes negligible. It actually reduces to the Ahar onov-Bohm effect [11], i.e., allows for the increment in th e phase of the wave function of the quasiparticle mov ing along its trajectory in the vector potential field. II. THEORY AND RESULTS A. Spectrum of Quasiparticles of the NS Structure FIG. 1: Two classes of trajectories in the normal metal of the NS structure in a magnetic field: trajectories forming the Andreev levels (a): trajectories colliding only with the dielectric boundary (b ). This figure has been taken from [9]. We proceed with a simplified model of NS structure in which the order parameter magnitude changes stepwise at th e NS boundary ( Δ ( x ) = Θ ( − x ), Im (Δ) = 0, a bulk superconductor in the region x < 0 and a normal metal layer in the region 0 ≤ x ≤ d ). It is also assumed that the magnetic field does not penetrate into the su- perconductor. The coherent properties observed in the pure normal metal can be attributed to its large ”coher- ence” length ξ$_{N}$ ( T ) = ℏ · v$_{F}$ π · k$_{B}$T ( v$_{F}$ is the Fermi velocity, k$_{B}$ is the Boltzmann constant) at very low temperatures ( ξ$_{N}$ ( T ) ≫ d ). Besides, the spectrum of quasiparticles was obtained assuming a negligible curvature of the NS boundary. thickness is equal to the field penetration depth δ . Si- multaneously, the Aharonov-Bohm effect generates per- sistent current (through the mechanism of the Andreev scattering of quasiparticles) in the normal layer near the NS boundary. If N and S metals are separated by a di- electric layer destroying the Andreev scattering, the addi- tional current disappears, and the Meissner effect returns to its usual form. The levels with energies no more than Δ (2Δ is the gap of the superconductor) appear inside the normal metal bounded by the dielectric (vacuum) on one side and the superconductor on the other side. Be- cause of the Aharonov-Bohm effect [11], the spectrum of the NS structure in a weak field is a function of the mag- netic flux. The specific feature of the Andreev quantum levels of the structure is that by varying field H (or tem- perature T ) each level in the well periodically comes into One can easily distinguish two classes of trajectories, inside the normal metal. One of them includes the trajec- tories which collide in succession with the dielectric and NS boundaries ( Fig.1 ). The quasiparticles moving along these trajectories have energies | E | < Δ and are local- ized inside the potential well bounded by a high dielectric barrier ( ≃ 1 eV ) on one side and by the superconducting gap Δ on the other side (Δ = 3 . 56 · k$_{B}$T$_{c}$/ 2, Δ(Nb) ≈ 1 . 42 meV). On its collisions, the quasiparticle is reflected specularly from the dielectric and experiences the An- dreev scattering at the NS boundary [12]. We introduce an angle α at which the quasiparticle hits the dielectric boundary. The angle is measured in the positive direc-