# September 9, 2011

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## summary what was been done

Run # Beam Dump magnet Collimator Radiator 10 um Al Target Comments
2339 Up 2 mm In Open Up 2 mm No R(upstream) = 2648/35092 = 0.075 e+/pulse,
R(downstream) = 3191/35092 = 0.091 e+/pulse
2341 Up 2 mm In Open Out No R(upstream) = 1088/35494 = 0.031 e+/pulse,
R(downstream) = 1328/35494 = 0.037 e+/pulse.

About 59% of photons are coming from the radiator. Bad

2342 Down 2 mm In Open Out No R(upstream) = 1586/36678 = 0.043 e+/pulse,
R(downstream) = 1888/36678 = 0.051 e+/pulse.
2343 Down 2 mm In Open Down 2 mm No R(upstream) = 2232/35488 = 0.063 e+/pulse.

About 32% of photons are coming from the radiator. Bad

2344 Centered In Open Centered No R(upstream) = 2683/35095 = 0.076 e+/pulse.
2345 Centered In Open Out No R(upstream) = 1039/35094 = 0.029 e+/pulse.

About 62% of photons are coming from the radiator. Bad

2346 Centered In Open Out No R(upstream) = 1286/35885 = 0.036 e+/pulse.

Improved shielding around dump.

Based on the previous results the beam is total crap, so beam tuned up.
2349 Centered In Open Out No R(upstream) = 404/35489 = 0.011 e+/pulse.
2350 Centered In Open Out No R(upstream) = 428/35093 = 0.012 e+/pulse.

Additional shielding around the vacuum window of the beam pipe.

2351 Centered In Open Centered No R(upstream) = 1314/35094 = 0.037 e+/pulse.

About 68% of photons are coming from the radiator. Still bad. Additional shielding around the vacuum window of the beam pipe is removed.

2352 Up 2 mm In Open Up 2 mm D2O bottle Production run.
2353 Up 2 mm In Open Out D2O bottle background check

threshold @A22 lowered to -100 mV

2354 Up 2 mm In Open Up 2 mm DU plate R(upstream) = 4228/188008 = 0.022 e+/pulse,
R(downstream) = 5169/188008 = 0.027 e+/pulse

Production run.

2355 Up 2 mm In Open Out DU plate R(upstream) = 766/44747 = 0.017 e+/pulse,
R(downstream) = 962/44747 = 0.021 e+/pulse

background check: about the same as w/ radiator in. Bad.
Threshold @A20 lowered to -100 mV

## Beam Realignment

Screen shot using Phosphorous screen


Electron beam on glass


12pm upstream view screen


12pm downstream view screen