Particles in a stream or river in China (7,3)

I believe the answer is:

cathode ray

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'particles in a stream' is the definition.
The definition suggests a singular noun which matches the answer.

'river in china' is the wordplay.
'river' becomes 'oder' (River Oder in central Europe).
'in' indicates putting letters inside.
'china' becomes 'Cathay' (historical name for China).
'oder' placed inside 'cathay' is 'CATHODE-RAY'.

'or' acts as a link.

Can you help me to learn more?

(Another definition for cathode ray that I've seen is " Stream that's charged".)

I've seen this clue in The Times and The Sunday Times.

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