AIDT 온디바이스 STEM 뫼스바우어 분광(Mössbauer) 무반동 감마선 초미세 상호작용 서보 엔진

using System;
using System.Runtime.CompilerServices;

namespace ZeliDesk.Stem.Mossbauer
{
    public readonly ref struct MossbauerState
    {
        public readonly double TransducerVelocityMms; // 속도 v (mm/s)
        public readonly double EnergyShiftNmev;       // 도플러 에너지 변위 Delta E (neV)
        public readonly double IsomerShiftMms;        // 추출된 이성질체 이동 delta (mm/s)
        public readonly double QuadrupoleSplittingMms;// 사중극자 분열 Delta EQ (mm/s)
        public readonly double RecoillessFractionF;   // 무반동 분율 f
        public readonly double IronOxidationState;    // 추정 철 산화수 (2.0=Fe2+, 3.0=Fe3+)

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public MossbauerState(double vel, double dE, double isVal, double qsVal, double fVal, double ox)
        {
            TransducerVelocityMms = vel;
            EnergyShiftNmev = dE;
            IsomerShiftMms = isVal;
            QuadrupoleSplittingMms = qsVal;
            RecoillessFractionF = fVal;
            IronOxidationState = ox;
        }
    }

    public ref struct MossbauerVelocityEngine
    {
        private const double C = 299792458.0;         // m/s
        private const double EGammaEv = 14412.497;    // 14.4 keV gamma ray for Fe-57
        private const double ErEv = 0.001957;         // 1.96 meV recoil energy

        private readonly double _debyeTempK;          // 시료 드바이 온도 theta_D (K)
        private double _currentVelocityMms;           // 현재 속도 (mm/s)
        private double _driveVoltageV;                // 모터 구동 전압 (V)

        public MossbauerVelocityEngine(double debyeK = 400.0, double maxVelMms = 10.0)
        {
            _debyeTempK = debyeK;
            _currentVelocityMms = 0.0;
            _driveVoltageV = 0.0;
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public MossbauerState StepServo(double targetVelMms, double measuredVelMms, double peakLeftMms, double peakRightMms, double tempK, double dtSec)
        {
            // 1. 선형 속도 추종 P-I 서보 루프 (100us)
            double velError = targetVelMms - measuredVelMms;
            _driveVoltageV = Math.Clamp(_driveVoltageV + velError * 0.25, -12.0, 12.0);
            _currentVelocityMms = measuredVelMms;

            // 2. 도플러 에너지 변위 계산 Delta E = (v / c) * E_gamma (neV)
            double velMps = _currentVelocityMms * 1e-3;
            double energyShiftEv = (velMps / C) * EGammaEv;
            double energyShiftNmev = energyShiftEv * 1e9; // neV

            // 3. 드바이-월러 무반동 분율 f(T) 근사 계산
            double debyeRatio = tempK / _debyeTempK;
            double fRecoilless = Math.Exp(-1.5 * (ErEv / (8.617e-5 * _debyeTempK)) * (1.0 + 4.0 * debyeRatio * debyeRatio));
            fRecoilless = Math.Clamp(fRecoilless, 0.01, 0.95);

            // 4. 이중선 피크 대칭점으로부터 이성질체 이동(IS) 및 사중극자 분열(QS) 추출
            double isomerShift = 0.5 * (peakLeftMms + peakRightMms);
            double quadSplitting = Math.Abs(peakRightMms - peakLeftMms);

            // 5. IS 및 QS 값에 기반한 철 산화수/배위 상태 판정
            // 통상 Fe2+ 고스핀: IS ~ 1.0~1.3 mm/s, QS ~ 2.0~3.0 mm/s
            // 통상 Fe3+ 고스핀: IS ~ 0.3~0.5 mm/s, QS ~ 0.5~1.0 mm/s
            double ironOx = (isomerShift > 0.7) ? 2.0 : 3.0;

            return new MossbauerState(
                vel: _currentVelocityMms,
                dE: energyShiftNmev,
                isVal: isomerShift,
                qsVal: quadSplitting,
                fVal: fRecoilless,
                ox: ironOx
            );
        }
    }
}