# -*- coding: utf-8 -*-
"""
Created on Fri Aug 27 15:14:48 2021

@author: Joschka
"""
from src import physical_constants as cs
import numpy as np


mu = 9.9* cs.mu_B/8

Grad_Bz = cs.m_Dy_164 * 9.81/(8*mu)

print("For levitation:")
print(f"dBz/dz = {Grad_Bz*1e4*1e-2:.4f} G/cm")
print("")

T = 1e-6
dt = 10e-3
sigma = np.sqrt(cs.k_B*T/cs.m_Dy_164) * dt

dz = 2 * sigma
print(f"cloud size: {sigma*1e3:.3f} mm")

#dz = 250e-6


Grad_Bz = 2 * dz * cs.m_Dy_164/(dt**2 * mu)


print(" ")
print("For Stern-Gerlach separation:")
print(f"dBz/dz = {Grad_Bz*1e4*1e-2:.4f} G/cm")
print(" ")

def cloud_pos(mF, dt = 10e-3):
    a = mF*mu*Grad_Bz/cs.m_Dy_164 - 9.81
    s = 0.5 * a *dt**2
    return s
a8 = -8*mu*Grad_Bz/cs.m_Dy_164 - 9.81
a8_neg = 8*mu*Grad_Bz/cs.m_Dy_164 - 9.81
a7 = -7*mu*Grad_Bz/cs.m_Dy_164 - 9.81
s8 = 0.5 * a8 * dt**2
s8_neg = 0.5 * a8_neg * dt**2
s7 = 0.5 * a7 * dt**2

for mF in np.arange(-8,9,1):
    print(f"for mF = {mF}: pos = {cloud_pos(mF) * 1e3} mm")


print(f"Total fall for m8 for acceleration due to magnetic field in same direction than gravity = {s8 * 1e3}mm")
print(f"Total lift for m8 for acceleration due to magnetic field in other direction than gravity = {s8_neg * 1e3}mm")
print(f"Fall without magnetic field = {-0.5 * 9.81 * dt**2 *1e3} mm")


print(f"s7 = {s7 * 1e3}mm")
print(f"diff = {(s8 - s7) * 1e3} mm")