Program Design for REMPI Jingming Long 08022010 Content

Program Design for REMPI Jingming Long 08/02/2010

Content ØDevice controlling program ØData processing program

Device controlling program Trigger Dye Laser(Scanmate) Excimer Laser Independent Computer Doubling crystal(Autotracker) Lecroy Oscilloscope Integration Tektronix ü

Scanmate module Trigger on or off Go to wavelength Set grating order Start /Stop scanning

Autotracker module Find maximum value Get intensity graph Set parameters Autotrack

Oscilloscope module Set mode of data record • One Byte for Y axis, 500 points for X About spectral resolution and data acquisition speed • Two Bytes for Y axis, 500 points for X • One Byte for Y axis, 10, 000 points for X ü • Two Bytes for Y axis, 10, 000 points for X Get experimental data Display in real time when adjust light

Resolution and speed (0, 65535) Y Oscilloscope window (9999, 65535) EXT trigger signal Mass spectra Delay time (9999, 0) (0, 0) (X, Y) is the position of oscilloscope window Why the maximum value of Y is 255 or 65535? Decided by bit-count of record and why the maximum value of X is 500 or 10000? Decided by sampling rate and memory X

Understand data structure =3 128 64 32 16 8 4 2 1 215 214 …. . …… 29 28 Binary: 1 0 0 0 0 27 2 6 2 5 2 4 2 3 2 2 2 1 2 0 0 0 0 1 1 High byte Low byte A bit alternatives 0 and 1 A byte is the smallest addressable unit of data and has 8 bits generally A word is the unit processed by machine code instructions In general, a word = 2, 4, 8 bytes according to operation system

Data save A folder as one experiment A. txt file as one wavelength step Each data file by named value of wavelength Like 20045. 1. txt, 20045. 2. txt…

For example, there are three experiments on HCl Scan range of wavelength as follow: 1. 20000~20050 cm-1 2. 20045~20080 cm-1 3. 20075~20100 cm-1 File a File b H + File c …… …… mass File 1 wavelength File 1000

Comparison: Old program: Three files will be saved. If we want to get a spectroscopy from 20000 cm-1 to 20100 cm-1, We have to match them with each other difficultly. New program: It’s easy to merge data of different experiment, because we Only choose one group of the overlapped data to plot a curve. Main devices are controlled by computer, It’s convenient to operate.

Data processing program Merge file as we want Auto mark the mass Plot 2 D spectroscopy

Thank you!