{"knowledge_schema": {"broad_category": "Physics \u2192 Quantum Mechanics \u2192 Scattering Theory", "refinement": "This problem involves the analysis of phase shifts in elastic scattering experiments, specifically focusing on the relationship between phase shifts and the scattering amplitude.", "specific_scope": "The task is to calculate the imaginary part of the scattering amplitude based on the given phase shifts for a specific energy of incident electrons.", "goal": "Determine the imaginary part of the scattering amplitude in the direction of the incident beam using the provided phase shifts."}, "summary": "This problem pertains to quantum mechanics and scattering theory, where the phase shifts from an elastic scattering experiment are used to calculate the scattering amplitude. The specific focus is on determining the imaginary part of the scattering amplitude based on the measured phase shifts of the system. The goal is to apply the relevant formulas and concepts to arrive at the correct value, which in this case is 251.271 fm."}