简介:InthisLetter,wepresentapossiblemethodologytodirectly'read'theforceonanatomviathephotonsemittedfromtheatom.Inthismethodology,themeanradiativeforceonanatomexertedbyexternalfieldscanbeexpressedasafunctionoftheaveragenumberofemittedphotonshNianditsderivativesviathegeneratingfunctionapproachdevelopedbyusrecently.
简介:AchargedspacecraftissubjecttotheLorentzforcewhenitorbitsacentralbodywithamagneticfield.TheinducedLorentzforceprovidesanewmeanofpropellantlesselectromagneticpropulsionfororbitalcontrol.ModelingtheEarthmagneticfieldasatilteddipolethatco-rotateswiththeEarth,thispaperdevelopsanonlineardynamicalmodelthatdescribestherelativemotionoftheLorentzspacecraftaboutanarbitraryreferenceorbit.Basedontheproposeddynamicalmodel,feasibilityofLorentz-propelledrendezvouswithnorestrictionsontheinitialstatesisinvestigated.Therendezvousproblemisthenformulatedasanoptimalcontrolproblem,andsolvedwiththeGausspseudospectralmethod(GPM).Numericalsimulationssubstantiatethevalidityofproposedmodelandmethod,andresultsshowthatthepropellantlessrendezvousisachievedatbothfixedandfreefinaltime.