branch was recorded and the maximum current at the first Fiske step branch I F c was defined as the current at which the junction voltage became greater then V$_{1}$ + V I$_{c}$ (see Fig.2). The amplitude of the first Fiske step was determined by substracting the quasiparticle current at Fiske step voltage I$_{q}$ from the switching current at Fiske branch I F c . Both Josephson critical current and amplitude of the first Fiske step for a given value of parallel magnetic field B$_{‖}$ were obtained. The I$_{c}$ ( B$_{‖}$ ) and I (1) F ( B$_{‖}$ ) dependencies were measured for both polarities of the bias current. The experimental cycle for the evaluation of the influence of Abrikosov vortices on the Fiske step amplitude consisted of the following steps: 1) The sample was heated to T > T$_{c}$ ; 2) A magnetic field B$_{⊥}$ of fixed value was applied; 3) The junction was cooled in the field B$_{⊥}$ up to T = 4 . 2 K , i.e. immersed in the liquid helium at normal pressure; 4) The magnetic field B$_{⊥}$ was turned off; 5) The amplitude of the first Fiske step was maximized by the parallel magnetic field B$_{‖}$ and the I − V curve with the first Fiske step branch was measured in order to obtain the voltage position of the first Fiske step; 6) The I$_{c}$ ( B$_{‖}$ ) curve was measured; 8) Both the Josephson critical current and the amplitude of the first Fiske step, were sup- pressed by a suitable parallel magnetic field B$_{‖}$ and the I − V curve was recorded in order to measure the quasiparticle current at V = V$_{1}$ . After the field cooling process the Abrikosov vortex density n$_{A}$ can be estimated as The measurements of the I$_{c}$ ( B$_{‖}$ ) dependence without trapped Abrikosov vortices were performed at T = 4 . 2 K (Fig.3, open circles). The Josephson penetration depth λ$_{j}$ was A. Junction Parameters VI. EXPERIMENTAL RESULTS AND DISCUSSION 10 n$_{A}$ ≃ B$_{⊥}$ Φ$_{0}$ . (12) 7) The I F 1 c ( B$_{‖}$ ) curve was measured;