1 Designing of a Simple, High performance Nitrogen laser for Laser Induced Florescence (LIF) studiesN Shafudah, and S Singh University of Namibia, Physics Department, Main campus, Namibia 340 Mandume Ndemufayo Avenue, Private Bag 13301, Pionierspark, Windhoek Thursday, October 27

2 CONTENTS Background Research Objectives Methodology Discussion Conclusion and Recommendations References Acknowledgements

3 Coherence, high directionality, intensity and monochromaticity are special properties that makes a laser light an imperial tool for such applications. Laser light form part of electromagnetic spectrum from Infra-red, X-ray, UV and Visible light. The most common types of lasers are found in Visible light.

4 Various types of lasers have been designed in the past for different purposes.These includes, TEA CO2 laser, Nd:YAG laser, Dye laser, Femtosecond laser, etc. Laser based research are in two forms; Development of laser sources and pulsed laser output and the use of lasers to study light induced phenomena. The optical emission spectroscopy for Laser Induced Plasmas (LIPs) emission is very important tool for laser material interaction. We propose a design of a design of a simple, high performance Nitrogen laser for LIF or LIPs studies.

5 Background Research Problem Research Objectives Justification of the study Methodology Results and Discussions Conclusions & Recommendations Acknowledgements References Vegetation produce their own food through photosynthesis and subsequently release fluorescence radiation. Various stress factor affects plants growth. Why the need for studying and recording vegetation's fluorescence spectra? Fluorescence spectra study is a tool to investigate plant effects on stress factors such as UV, water and minerals

6 The purpose of this study is to design a Nitrogen laser for LIFBackground Research Problem Research Objectives Justification of the study Methodology Results and Discussions Conclusions & Recommendations Acknowledgements References PRIMARY OBJECTIVE The purpose of this study is to design a Nitrogen laser for LIF

7 To design a good Nitrogen laser for LIF studies.Background Research Problem Research Objectives Justification of the study Methodology Results and Discussions Conclusions & Recommendations Acknowledgements References SPECIFIC OBJECTIVE To design a good Nitrogen laser for LIF studies.

8 BLUMEIN CIRCUIT Background Research Problem Research ObjectivesMethodology Results and Discussions Conclusions & Recommendations Acknowledgements References BLUMEIN CIRCUIT

9 MATERIALS AND METHODS The N2 laser consist of plasma tube, spark gap, blumein circuit, two plate capacitors, high voltage power supply, trigger circuit and gas flow supply. Fast high voltage (10 kV) was required for volumetric discharge. Spark gap were treated as main switches. Upper plate capacitors were separated by 5mm gap and 15mm from the dielectric. The capacitance of each capacitors was found to be 6ns. Thickness sheet of 0.1mm with dielectric and electrode was made from tungsten.

10 SPECTRO-FLUORIMETER leaf Nitrogen laser read out Recorder FilterBackground Research Problem Research Objectives Justification of the study Methodology Results and Discussions Conclusions & Recommendations Acknowledgements References SPECTRO-FLUORIMETER leaf Nitrogen laser read out Recorder Filter Telescope Monochromator Pm-tube

11 Background Research Problem Research Objectives Justification of the study Methodology Results and Discussions Conclusions & Recommendations Acknowledgements References RECOMMENDATION The annual effective dose in basic school playing ground was found to be below the recommended dose limit per year. However, there is a need to follow up on predicted future annual effective dose in order to validate the model used. Children’s background exposure such as dietary intake, inhalation of dust at home were not accounted for in this study. Therefore this should be considered to enable calculation of overall risk to children. Scientific community should consider sampling at monthly to yearly interval in order to observe the seasonal trend of potentially toxic trace elements in the soils of schools playgrounds. Researchers should also consider other part of Greater Accra especially Ga West which was not covered in this study.

12 Background Research Problem Research Objectives Justification of the study Methodology Conclusions & Recommendations Acknowledgements References Basic school managements should consider proper constructions of their play grounds. This involves introducing grass playing fields in order to avoid dust inhalable by children during their games at schools. Regulatory bodies of Ghana should use results from this study for authorities’ regulation purposes.