AIDT 온디바이스 STEM 스핀 교환 광학 펌핑(SEOP) 과편극 제논-129 핵스핀 서보 엔진

using System;
using System.Runtime.CompilerServices;

namespace ZeliDesk.Stem.QuantumOptics
{
    public readonly ref struct HyperpolarizationState
    {
        public readonly float XenonPolarizationPercent;
        public readonly float RubidiumPolarizationPercent;
        public readonly float SpinExchangeRateHz;
        public readonly float NmrGainMultiplier;

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public HyperpolarizationState(float pXe, float pRb, float gammaSE, float gain)
        {
            XenonPolarizationPercent = pXe;
            RubidiumPolarizationPercent = pRb;
            SpinExchangeRateHz = gammaSE;
            NmrGainMultiplier = gain;
        }
    }

    public ref struct SeopHyperpolarizedXenonServo
    {
        private const float GammaXeRelaxSec = 0.00035f; // T1 relaxation rate (T1 ~ 45 min)
        private const float BoltzmannBasePol = 3.2e-6f;  // At 3 Tesla 300K

        private float _runningPXe;
        private float _runningPRb;

        public SeopHyperpolarizedXenonServo(float initialPXe = 0.05f)
        {
            _runningPXe = initialPXe;
            _runningPRb = 0.95f;
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public HyperpolarizationState UpdateServo(float laserPowerWatts, float ovenTempC, float dt = 0.0001f)
        {
            // Rubidium vapor density [Rb] vs temperature (Killian formula proxy)
            float tempK = ovenTempC + 273.15f;
            float rbDensityM3 = MathF.Exp(26.4f - 4040.0f / tempK) * 1.0e14f;

            // Optical pumping rate R_opt ~ Laser Power
            float rOpt = laserPowerWatts * 125.0f; // s^-1
            float gammaSD = 40.0f + (rbDensityM3 * 1e-19f) * 15.0f;
            float targetPRb = rOpt / (rOpt + gammaSD);
            _runningPRb += (targetPRb - _runningPRb) * (dt * 150.0f);

            // Spin exchange rate gamma_SE = k_SE * [Rb]
            float gammaSE = 2.2e-21f * rbDensityM3; // ~ 0.02 - 0.15 s^-1

            // Dynamic Xenon polarization evolution
            float dPXe = gammaSE * (_runningPRb - _runningPXe) - GammaXeRelaxSec * _runningPXe;
            _runningPXe += dPXe * (dt * 60.0f); // scaled integration
            _runningPXe = MathF.Clamp(_runningPXe, 0.0f, 0.95f);

            float gain = _runningPXe / BoltzmannBasePol;

            return new HyperpolarizationState(_runningPXe * 100.0f, _runningPRb * 100.0f, gammaSE, gain);
        }
    }
}