beam heigth

[Stefan Thomas]

Dear community,
in the below quoted example I see a very small collision between the beam and the natural sign.
Is there a way to alter the maximum beam-heigth generally?
Here the example:

\version "2.13.3"

{ 
  #(set-accidental-style 'neo-modern)
  \clef "treble_8" << {fis' 16  dis' d''     dis' 
       
        \repeat "unfold" 2 {  fis' dis' d'' dis'   }
      
    \context Voice << {   \repeat "unfold" 4 { f' e'' b' }} {s2 }>> f'' 16 b a, b  fis' c' f'' b  } \\ 
  
  {r4  r16 e, 8  g 16 ~ g a, \< g fis  f' 8 \> gis ~ \! | %47
        gis 8[  d ]   es[ d 16 gis 16 ] ~ gis 8[ a, ~ ] a, 16 c' 8. } >> }