Perhaps you should try some spelling variations:
"particle concentrations" » "particle concentration", "particle correlations", "particle penetration"
"particle accelerations" » "particle acceleration", "particles acceleration", "particelle acceleratori"
"particles accelerated" » "particles acceleration", "partially accelerated", "lattices accelerated"
"particle accelerator" » "particle acceleration"
"particle accelerators" » "particle accelerations", "particle acceleration", "particle accelerating"
"particle accelerated" » "particle acceleraton", "particle acceleration", "partially accelerated", "particle acceleratond", "particle accelerationd", "practice accelerated"
"particle accelerate" » "particle acceleraton", "particle acceleration", "practice accelerate"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (("particle accelerator") OR ((((((("particle accelerators") OR ("particle accelerated"))) OR ((("particle accelerate") OR ("particles accelerated"))))) OR ((("particle accelerations") OR ("particle concentrations")))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"particle accelerator\") or (((((((\"particle accelerators\") or (\"particle accelerated\"))) or (((\"particle accelerate\") OR (\"particles accelerated\"))))) or (((\"particle accelerations\") or (\"particle concentrations\"))))))".
• Removing quotes may allow a broader search: (( particle accelerator ) or ((((((( particle accelerators ) or ( particle accelerated ))) or ((( particle accelerate ) OR ( particles accelerated ))))) or ((( particle accelerations ) or ( particle concentrations )))))).
• Adding a wildcard symbol may retrieve word variants: (("particle accelerator") or ((((((("particle accelerators") or ("particle accelerated"))) or ((("particle accelerate") OR ("particles accelerated"))))) or ((("particle accelerations") or ("particle concentrations"))))))*.