Possible Clues:

• Ruin note about elementary particle
• One in rut possibly: it's very small and difficult to detect
• Particle of fresh lime, perhaps, Ken picked up
• Alan flitting between both sides in ring for particular object
• Ruin note about subatomic particle
• It's not charged
• Arranged tour in north-east — it's free of charge
• Rumour of recent threesome — name's taken but one's not charged
• Urine not flowing? It's definitely not a big thing!
• Tiny particle