IDs
    #main       -> main SVG
    #background -> decorative SVG elements
    #atdSig     -> id for signals on ATD computer
    #carbonRef  -> Carbon reference dot
    #C12mark    -> Carbon reference marker
    #cRef       -> marker for C12


IDs of Object Manipulatives
    #vDial      -> Velocity selector
    #heaterSwitch   -> Switch on #heater
    #ioniserSwitch  -> Switch on #ioniser
    #datanalyser     -> Do data collection
    #vapourChamber  -> Vapour chamber
    #heater         -> heating element


IDs of Chemical species
    #moleculei  -> molecules 1 to 50 of vapourised species
    #electronsi -> 
    #MIi        -> Molecular ions shooting off into space


counters
    numMole -> count of vapour molecules (50)
    MICount -> count of molecular ions   (200)
    electronCount -> count of electrons  (25)


Classes
    electron 
    molecule
    ions


Functions
    onHeater()      ->Turn on #heater
    onIoniser()     ->Turn on #ioniser
    clearIons()     ->Clear Analyser 
    vDialAOR()      ->Obtain value of vDial knob
    carbonReference() ->Calculate diameter of carbon trajectory
    massRand()      -> probabilistic determination of mass of isotopes by relative abundances


variables
    Fixed
        B -> magnetic field strength
        numMole -> number of vapour molecules
        vMole -> speed of the vapour molecules

    manipulatives
        element-> selected element, in the form of eg mass_Cu
        velSel -> #vDial controlled    
        heating -> heater on
        ionising -> ioniser on
        acc -> acceleration of particle, constantly updated;
        theta -> angle of travel at instant


DOM Objects
    vDial       -> #vDial
    carbonRef   -> #carbonRef
    C12mark     -> #C12mark