Resonance VM200 User manual

615 –VM200 VUV Monochromator/ Spectrometer
Operating Manual
www.resonance.on.ca

TABLE OF CONTENTS
TABLE OF CONTENTS............................................................................................................................. 2
TABLE OF FIGURES ................................................................................................................................. 3
GENERAL INFORMATION...................................................................................................................... 4
SYSTEM OVERVIEW.................................................................................................................................. 4
PACKING LIST........................................................................................................................................... 5
SETUP........................................................................................................................................................... 6
SYSTEM OPERATION .............................................................................................................................. 7
OPERATING IN MONOCHROMATOR MODE............................................................................................... 7
PERFORMING A SCAN................................................................................................................................ 8
OPERATING IN SPECTROMETER MODE .................................................................................................... 9
OBTAINING SPECTRA................................................................................................................................ 9
MOUNTING AND OPERATING WITH A LAMP.................................................................................11
CALIBRATING THE MONOCHROMATOR........................................................................................12
FOCUSING THE VM200...........................................................................................................................13
IN MONOCHROMATOR MODE..................................................................................................................13
IN SPECTROMETER MODE........................................................................................................................14
ADD-ON OPTIONS....................................................................................................................................15
APPENDIX:.................................................................................................................................................16
SYSTEM COMPONENTS ............................................................................................................................16
Monochromator ..................................................................................................................................16
Photodiode Detector............................................................................................................................17
CCD.....................................................................................................................................................17
Adjustable Slits....................................................................................................................................18
NIST CALIBRATION.................................................................................................................................19

TABLE OF FIGURES
FIGURE 1: CUTAWAY VIEW OF VM200 ........................................................................................................... 4
FIGURE 2: MOTOR DRIVE CONTROLLER BOX.................................................................................................. 7
FIGURE 3: DETECTOR CONNECTIONS .............................................................................................................. 7
FIGURE 4: PHOTODIODE INDICATOR LIGHTS &ZERO BUTTON........................................................................ 8
FIGURE 5: SLIT WIDTH ADJUSTMENT MICROMETER ....................................................................................... 8
FIGURE 6: CCD USB PORT ............................................................................................................................. 9
FIGURE 7: CCD INDICATOR LIGHTS &ZERO BUTTON .................................................................................... 9
FIGURE 8: SLIT WIDTH ADJUSTMENT MICROMETER ......................................................................................10
FIGURE 9: EXAMPLE OF CCD SIGNAL LEVEL NON-LINEAR EFFECT.................................................................10
FIGURE 10: EXIT SLIT FOCUSING COLLAR AND FASTENING SET-SCREW..........................................................13
FIGURE 11: CCD FOCUSING COLLAR AND FASTENING SET-SCREW.................................................................14
FIGURE 12: GRATING EFFICIENCY CURVE.......................................................................................................16
FIGURE 13: TYPICAL RESPONSE CURVE OF THE AXUV PHOTODIODE.............................................................17
FIGURE 14: TYPICAL RESPONSE CURVE OF THE HAMAMATSU S9840 CCD ....................................................18
FIGURE 15: NIST STANDARD CALIBRATION CURVE......................................................................................19
FIGURE 16: NIST CALIBRATION MEASUREMENTS .........................................................................................19
FIGURE 17: NIST TRACEABLE QUANTUM EFFICIENCY CHART ......................................................................20

GENERAL INFORMATION
SYSTEM OVERVIEW
The Resonance Ltd. monochromator/spectrometer is designed for laboratory applications
yet is rugged enough for field use. The system is hermetically sealed and can be used in the
vacuum ultraviolet region (wavelengths below 190 nm) with a nitrogen or helium purge, or
by connecting to a vacuum system either through the slits or through a 2.75" Conflat® style
flange on its base. The compact size of the unit results in a small internal volume (only 2
litres), allowing for a rapid pumping time.
A single grating is used to maximize throughput in the vacuum ultraviolet region and to
minimize scattered light. The standard grating is a 45mm square f/4.2 concave
holographic grating with an aluminum/MgF2 overcoat. The reflective properties of this
or any grating can be severely damaged by mechanical contact with any solid, liquid or
vapor. Never blow on the surface of the grating or onto the slit openings.
Figure 1: Cutaway view of VM200
Concave Holographic
Grating
Entrance Slit
Exit Slit
2 ¾” CF Flange
pumping port

PACKING LIST
Below is a list of all the components shipped with the VM200. If you find any of these
items to be missing, please contact Resonance Ltd. to arrange to have it delivered.
Item Quantity
VM200 Monochromator 1
Motor Drive Electonics Box 1
EUV Si Diode 1
CCD Array 1
18 VDC Power Supply 1
5 VDC Power Supply 1
Software Disc 1
LabJack 1
USB Cable 1
BNC Cable 1
2 ¾” Viton Gasket 1
2 ¾” Copper Gasket 1
018 Viton O-rings 3
¼ - 28 x 1” SS socket head bolts 6

SETUP
The VM200 is supplied with either an exit slit, to allow use of the system as a
monochromator, or a CCD for spectrometer operation or both.
In monochromator mode, a detector can be mounted at the exit slit either by a 2 ¾” CF
flange or a 1”-20 thread with a shoulder to hold and compress the o-ring (if vacuum
operation is required). In spectrometer mode, the CCD module is mounted in the place of
the exit slit using 4 4-40 x 1 ½” stainless steel socket head cap screws.
The VM200 spectrometer can be fixed in any orientation and attached to a VUV light
source that attaches to a CF flange or a 1”-20 thread with a shoulder to hold and
compress the o-ring for vacuum operation. If purged operation is desired, an adaptor
flange can be used to allow purge gas to enter the spectrometer through the flange at the
bottom of the spectrometer and exit the entrance slit. Vacuum or purged operation is
necessary only when observing wavelengths less than 190 nm. Keep in mind that the
VUV properties can be easily damaged by organic contaminants therefore use only oil-
free purge gas.
For mounting to a purge system, light source, or detector a standard CF flange that
screws directly onto the 1”-20 at the base has been supplied (see Figure 1). If a CF flange
is not compatible with the system, any counter-bored flange design (NW, ASA, etc) with
a female 1”-20 tpi thread adaptor with a shoulder to hold and compress the o-ring can be
used. Since the design of the interface to a lamp will depend on the lamp design, we have
supplied one 2.75” CF type flange, which screws directly onto the 1”-20 flange to allow
maximum adaptability.
Note: if while mounting the threads bind, do not force any further. The piece may
be loosened by applying a small amount of isopropyl alcohol to the bottom of the
thread. After capillary action has drawn the liquid up into the thread the piece may
be unscrewed.

SYSTEM OPERATION
OPERATING IN MONOCHROMATOR MODE
1. Plug the motor cable into the motor drive controller box
Figure 2: Motor Drive Controller Box
2. Plug in the driver box power supply
3. Plug in the USB cable
4. Plug in the LabJack USB cable
5. Connect the detector BNC cable from the detector signal output to the LabJack
6. Plug in the detector power supply
Figure 3: Detector Connections

7. Start the Program
8. Make sure the ‘Stepper’ and ‘Photodiode’ indicator lights both turn green
9. Click on the ‘Zero’ button
Figure 4: Photodiode Indicator Lights & Zero Button
1. You are now ready to obtain spectra
PERFORMING A SCAN
1. Set the slits to the desired width for the ideal signal vs resolution. Note: There is
backlash in the micrometer dial, so it is best to completely close the slits (to
approximately 10 micron below zero) and then open them to the desired
width, otherwise the set slit width may not match the actual width.
Figure 5: Slit Width Adjustment Micrometer
2. Enter the desired starting wavelength for the scan in the box
3. Enter the desired ending wavelength for the scan in the box
4. Set the scan speed/step resolution by moving the sliding bar to the desired step
increment
5. Click on the button
Indicator lights

OPERATING IN SPECTROMETER MODE
1. Repeat steps 1-3 from monochromator mode
2. Plug in the CCD USB cable
Figure 6: CCD USB Port
3. Start the program
4. Make sure the ‘Stepper’ and ‘CCD’ indicator lights both turn green
5. Click on the ‘Zero’ button
Figure 7: CCD Indicator Lights & Zero Button
6. You are now ready to obtain spectra
OBTAINING SPECTRA
1. Set the entrance slit to the desired width for the ideal signal vs resolution. Note:
There is backlash in the micrometer dial, so it is best to completely close the
slits (to approximately 10 micron below zero) and then open them to the
desired width, otherwise the set slit width may not match the actual width.
Indicator lights

Figure 8: Slit Width Adjustment Micrometer
2. Set the integration time and the number of averages to the desired levels. (Note:
at higher signal levels [>2000 counts] the CCD begins to respond non-
linearly, resulting in the appearance of loss of resolution and a rounded peak,
therefore it is idea to adjust the integration time to keep the signal to a
reasonable level).
Figure 9: Example of CCD signal level non-linear effect
3. Enter the desired center wavelength in the box at the bottom of the
screen and click the button
4. If it appears that the actual center wavelength does not match the wavelength
entered, there is a CCD centre offset function in the settings tab
() that allows the user to compensate for this. Due to some non-
linear effects within the system, this offset may need to be adjusted based on the
centre wavelength setting.
5. To remove the dark spectrum from the measured signal, turn off the light source
and click on to store it to memory and on to subtract
it from the displayed signal.
6. Turn the light source back on
Rounded peak &
appearance of
loss of resolution
due to CCD non-
linear effect