CONTENTS Emission Measurements Samples Preparation Fluorescence spectra Difficulties and limits...

NASIR KHAN

SBL Meeting 2014, Nov 21st

Measurement of Primary Emission Spectrum of Mixed LS

CONTENTS

• Emission Measurements

• Samples Preparation

• Fluorescence spectra

• Difficulties and limits

• Results and conclusions

• APPARATUS– Agilent Technology Cary Eclipse Spectrophotometer

• METHODS

EMISSION MEASUREMENTS

– Diluted PPO in Cyclohexane.

– Diluted bisMSB in Cyclohexane.

– LAB-LS (3g/L PPO + 30mg/L bisMSB)

– Ultima Gold-F (UGF)

– UGF-LS (LAB-LS + UG-F in 9:1 by weight)

SAMPLE PREPARATION

PPO Back Face samples excited at 300nm• Different concentrations• Low concentration gives the expected primary emission using Back Face geometry • More concentration; more stokes shift• Self absorption

PPO Front Face

Concentration makes small difference

PPO Front Face & Back FaceEven concentrated sample gave primary spectrum

bisMSB Front Face & Back Face

Method makes valuable changes

LAB-LS Front Face and Back Face We expect Front Face LAB-LS should show spectrum of PPO as primary emission, But it does not show, as the light can be absorbed by bisMSB also.Front Face of a liquid gives detail of its constituents depending upon the excitation range, LAB-LS shows all components.

Continue.…Using the same Front Face method we tried to find the primary emission of Ultima Gold-F.But unfortunately we found no fruitful results as we don’t know its constituents.

UGF

Back Face

Front Face

LS-UGFGreen, Back Face, will reach to detector.

CONCLUSION Method

– Self-absorption & Re-emission problem in Back Face setup.

– Front Face geometry adopted.

– We expect primary emission of LAB-LS will be more like PPO.

Spectroscopy

– We can not find Primary emission of LAB-LS or bisMSB or UG-F with

photo spectrometer.

– Using X-Ray spectroscopy we may find primary emission of LAB-LS

and may also of Ultima Gold-F.

Thank you forattention….!

bisMSB Back Face Excited at 340nm

– Low concentration is giving the expected Primary emission.– High concentration shows stoke shift.

Front Face bisMSB Different concentration = same expected Emission.