SLAC, HiRes T-461:“FLASH” part 1

Justin Findlay

App

arat

us

Data: ntuple

• Run• Event• Type: event type• Ne-: number of electrons

• n: blind north PMT• N: signal north PMT• s: blind south PMT• S: signal south PMT• Pressure• Temperature• hV: high voltage

• Flow: gas flow• Mixture: gas mixture• Quality: event quality• NL: signal PMTs’• SL, nearest LED event• Np: each PMT’s• Np, nearest pedestal• sp• Sp

Data: runs

Cuts: high voltage

before after

Cuts: LED

before

Cuts: LED

afterSbar

LE

D

Nbar

LE

D

Data Reconstruction

• Subtract pedestal

• Correct PMT gain wander

• Extrapolate from LED events to all events

• Convert blind PMT gain to signal PMT gain

• Subtract backgroundmeasured by blind PMT

pedbackgroundcorrectedsubtracted

ped

HCcorrectedbackground

pedpedLED

LEDpedLEDcorrected

pedLED

LEDLEDpedLEDLEDLED

ped

ssμSS

ss

Sμ

SSSS

SSSCS

SS

SC,SSCS

SS

42

Cuts: signal PMT correlation

Blue: non-ethylene data

Black: ethylene data

Cuts: Ne- per linearity, air

Cuts: Ne- per linearity, N2

Yield

Yield: function

Y: yield

C: constant

0 ∙ and p’: represent wavelength specific constants

p: pressure

pp

CY1

'

1

0

Yield: fit, air

Yield: fit, N2

Yield

• Still need to incorporate errors propagated

• 2 / Ndf too large for result to be reliable

• Try for the principal

lines

6or3

0

0

1

'

1i

i

ii

pp

CY

Systematic Error

• Account for systematic biases and failings

- PMT Gains

- Pedestals / Data Acquisition System

- Beam Monitor

- Temperature

- Pressure

The End