/// <summary>Calculate the average radiation effect to all habitats. returns true if successful.</summary>
public bool CalculateRadiationImpact()
{
if (radiation < 0)
{
radiation_impact = 1.0;
return(true);
}
if (habitatInfos == null)
{
BuildHabitatInfos();
}
if (habitatInfos == null)
{
return(false);
}
radiation_impact = 0.0;
int habitatCount = 0;
foreach (var hi in habitatInfos)
{
radiation_impact += Radiation.DistanceRadiation(1.0, hi.distance);
habitatCount++;
}
if (habitatCount > 1)
{
radiation_impact /= habitatCount;
}
return(true);
}
/// <summary>
/// get the total radiation emitted by nearby emitters (used for EVAs). only works for loaded vessels.
/// </summary>
public static double Nearby(Vessel v)
{
if (!v.loaded || !v.isEVA)
{
return(0.0);
}
var evaPosition = v.rootPart.transform.position;
double result = 0.0;
foreach (Vessel n in FlightGlobals.VesselsLoaded)
{
var vd = n.KerbalismData();
if (!vd.IsSimulated)
{
continue;
}
foreach (var emitter in Lib.FindModules <Emitter>(n))
{
if (emitter.part == null || emitter.part.transform == null)
{
continue;
}
if (emitter.radiation <= 0)
{
continue; // ignore shielding effects here
}
if (!emitter.running)
{
continue;
}
var emitterPosition = emitter.part.transform.position;
var vector = evaPosition - emitterPosition;
var distance = vector.magnitude;
result += Radiation.DistanceRadiation(emitter.radiation, distance);
}
}
return(result);
}
public double AverageHabitatRadiation(double radiation)
{
if (habitatShieldings.Count < 1)
{
return(radiation);
}
var result = 0.0;
foreach (var shieldingPartsList in habitatShieldings.Values)
{
var remainingRadiation = radiation;
foreach (var shieldingInfo in shieldingPartsList)
{
// for a 500 keV gamma ray, halfing thickness for aluminium is 3.05cm. But...
// Solar energetic particles (SEP) are high-energy particles coming from the Sun.
// They consist of protons, electrons and HZE ions with energy ranging from a few tens of keV
// to many GeV (the fastest particles can approach the speed of light, as in a
// "ground-level event"). This is why they are such a big problem for interplanetary space travel.
// Beer-Lambert law: Remaining radiation = radiation * e^-ux. Not exact for SEP, but close enough to loosely fit observed curves.
// linear attenuation coefficent u. Asssuming an average CME event energy Al shielding 10 ~= 30 g/cm^2.
// Averaged from NASA plots of large CME events vs Al shielding projections.
var linearAttenuation = 10;
// However, what you lose in particle radiation you gain in gamma radiation (Bremsstrahlung)
var incomingRadiation = remainingRadiation;
remainingRadiation *= Math.Exp(shieldingInfo.thickness * linearAttenuation * -1);
var bremsstrahlung = incomingRadiation - remainingRadiation;
result += Radiation.DistanceRadiation(bremsstrahlung, Math.Max(1, shieldingInfo.distance)) / 10; //Gamma radiation has 1/10 the quality factor of SEP
}
result += remainingRadiation;
}
return(result / habitatShieldings.Count);
}
public double AverageHabitatRadiation(double radiation)
{
if (habitatShieldings.Count < 1)
{
return(radiation);
}
var result = 0.0;
foreach (var shieldingPartsList in habitatShieldings.Values)
{
var remainingRadiation = radiation;
foreach (var shieldingInfo in shieldingPartsList)
{
// for a 500 keV gamma ray, halfing thickness for aluminium is 3.05cm. But...
// Solar energetic particles (SEP) are high-energy particles coming from the Sun.
// They consist of protons, electrons and HZE ions with energy ranging from a few tens of keV
// to many GeV (the fastest particles can approach the speed of light, as in a
// "ground-level event"). This is why they are such a big problem for interplanetary space travel.
// We just assume a big halfing thickness for that kind of ionized radiation.
var halfingThickness = 1.0;
// halfing factor h = part thickness / halfing thickness
// remaining radiation = radiation / (2^h)
// However, what you loose in particle radiation you gain in gamma radiation (Bremsstrahlung)
var bremsstrahlung = remainingRadiation / Math.Pow(2, shieldingInfo.thickness / halfingThickness);
remainingRadiation -= bremsstrahlung;
result += Radiation.DistanceRadiation(bremsstrahlung, shieldingInfo.distance);
}
result += remainingRadiation;
}
return(result / habitatShieldings.Count);
}