PHENIX Status, 2/22/11Takao Sakaguchi

Integrated events• Events in data files named “PHYSICS”

RPC Background investigationHit Rates Tunnel Scalers vs RPC Rates

- RHIC store 15172.

Yellow beam dumped, only blue beam left in ring- (blue runs from south to north through PHENIX IR)

Run 331180Yellow beam dumped

Injection

Yellow beam dumpedOrbit correction test

Orbit correction test

Run 331180

3/11

Run 331176

Hit Rates Tunnel Scalers vs RPC Rates480k clock trigger events.

run 331180

Blue beam only

RPC3S

RPC3N

4/11

We see large backgroundFrom Blue beam

Hit Rates Tunnel Scalers vs RPC Rates

clock trigger events.

Before yellow dump, both beams are on

run 331176 We see large backgroundFrom Both beam

Note, Vertical scale is different from the previous.

Hit Rates Tunnel Scalers vs RPC Rates - Same run as before, but extracted collision-related timing.

run 331176 RPC3S

RPC3N

6/11

Even for collision events,We see background in center region

-location of tunnel scalers south

RPC3South

South Muon arm structure

7/11

Special runs next couple days

backup

Hit Rates Tunnel Scalers vs RPC Rates - Cosmics. run 331346. 260k clock trigger events.

run 331346

Cosmicsno beam

RPC3S

RPC3N

10/11