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Echelle
Spectra Analyzer ESA
Compact Echelle Spectrometer with extraordinary high spectral
resolution for different applications in atomic spectroscopy, for active and
passive coupling with different radiation sources.
Echelle Spectra Analyzer ESA 3000, Electronic and optical
module
Functionality
The Echelle Spectra Analyzer ESA 3000 was developed
for measurements of complex spectra with a high spectral resolution. The
entire UV and visible wavelength range is detected simultaneously with a
resolution of few pm.
ESA 3000 is used in atomic spectroscopy, detecting simultaneously all
spectral lines with high resolution, relevant for analysis of material,
avoiding the overlay of lines. The optional use of an image intensifier
permits time-resolved measurement (decay measurements)with
a temporal resolution of few nanoseconds. The control of external radiation sources , e.g. laser, and the well-defined time-correlated
measurement of the radiation predestines ESA 3000 for Laser Induced Breakdown
Spectroscopy (kurz LIBS), for applications for
simultaneously multi-element analysis.
The system consist of an Echelle
spectrometer aand the electronic control unit. The
electronic unit contains the voltage supplies, the ADC, framegrabber
and fastpulse generator board besides the
industrial PC, all located in a 19" rack. The fastpulse
generator board is able to perform the time-control of the entire experiment
or to synchronize the system to an external signal.
Inside the spectrometer an intensified CCD-camera is integrated, consisting
of an image intensifier and CCD sensor array of high pixel density. The
camera is placed in the image plane of the spectrometer. The MCP (Micro
Channel Plate)-image intensifier is controlled (open-close) by electric
signals and permits the time-resolved measurment of
weak signals respectively of dynamic processes.
The time-resolved simultaneous detection of the entire relevant wavelength
range permits the optimalö selection of
spectral lines according to the application and an optimization of the S/N
ratio.
For fast spectra processing non-relevant spectral can be summarized and
discarded at an early stage of data processing. A bit pattern,stored in a memory (RAM) provides an orientation
for the summarization of selected lines on the detector array.(Line-Binning).
During read-out of lines selected parts of a line can be summarized
(Column-Binning). Using the binning feature the spectra processing can be
accelerated up to one order of magnitude.
Offered as an OEM-version, ESA 3000 is easy to integrate into existing
systems and plants. The patented optical setup does not have any moving
parts. The compact construction guarantees a high stability of the wavelength
calibration and proves the industrial use of the device.
Optical Setup
Optical
Setup
An Echelle grating, which is positioned under a flat angle
of incidence, produces up to 100 diffraction orders. An additional quartz
prism in front of the grating separates the overlapping orders by splitting
them vertically to the direction of the spectrum. In that way the compact
spectrograph covers a total spectrum length of over one meter on a one square
inch focal plane. The optical parameters of the entire setup fit the relevant
spectral range to the sensitive range of the camera of 25 mm x 25 mm. The linear
dispersion is fitted to the pixel size of the camera.
Echelle Spectra(entire
camera picture)
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Wavelength
spectrum, calculated from the Echelle picture;
Cr-line group at 285 nm
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CN-CN-molecul spectrum with cyanband
head at 388.34nm
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For system control
and data processing a control and analytical software featuring various
analytical tools is provided (see software ESAWIN).
The following pictures provide a first impression on the different
possibilities for data visualization.
Visualization of data
Spectra
visualization of a steel sample, upper left camera picture, upper right
selection of particular lines, lower spectrum sector
Wavelength
respectively element analysis program – Echelle
recording of a tool steel
Technical specification
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Echelle Spectrometer
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Standard
version 3000 EV/i
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UV-Version
3000 EV/i
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Spectral range for simultaneous detection
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200 - 780 nm
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190 - 400 nm
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Linear dispersion per pixel (24 µm)
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0.005 nm at 200 nm
0.015 nm at 600 nm
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0.0027 nm at 190 nm
0.0051 nm at 350 nm
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Spectral resolution(l/Dl) FWHM
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20000
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30000
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Spectral orders
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30 - 120
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110 - 205
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Focal length
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25 cm
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Image plane
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25 x 25 mm
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Dimensions
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300 x 200 x 500 mm
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Weight
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13,5 kg
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Option
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Fiber
optical input, water-cooling unit
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ICCD-camera:
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Kodak KAF-1001
(1024x1024 pixels);
dark current 25 pA/cm2 at 20°C;
saturation charge 500.000 electrons
with gateable image intensifier(MCP); temporal
resolution approximately 20 ns; on-chip-integration time up to 3 min,
double correlated sampling, stabilization of temperature, closed
water-cooling circuit.
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New!!
Now avaible with
Back-thinned CCD-camera:
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Hamamatsu S7171 (512 x 512 pixles);
dark current 110 pA/cm2 at 25°C;
saturation charge 300.000 electrons;
one-stage TE-cooled;
closed water-cooling circuit;
enabled spectral range detection up to 1100 nm
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Electronic unit
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Fast-pulse-generator:
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Control
of image intensifier of ICCD camera, open time adjustable 20 ns - 6 ms;
control of pulsed radiation surces (laser)and
synchronization with external trigger signal (master- and slave mode - 2
TTL-signal outputs);programmable TTL-pulse generation ; Cw-option
permits measurement of long-time plasma
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Controller:
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Prozessor AMD K6-3, 550 MHz; hard disk min. 20 GB;
128 MB RAM, CDRW-burner, 2 MB Video-RAM with 16 Bit ADC / 500 (1000) kHz
conversion rate, WINDOWS 2000; keyboard
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Interfaces:
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serial
RS-232, Ethernet, USB, VGA-monitor, printer, I/O-ports for process control
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Voltage
supply:
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230
V, 4 A, 50 / 60 Hz (optional 110/120 V, 60 Hz)
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Software
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Control
and analytical software ESAWIN
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- Dialog controlled operation, on-line help
- Setting of measuring parameter, Method-specific
control of the measurement (start, stop with time r pulse selection,
manual stop, externally triggered)
- Selection of spectra display, line selection,
display of line groups of detected elements
- Automatic qualitative multi-element-analysis
- Setting of output parameters
- Data storage (Archive functions, use of standard
and atom database, data import and export)
- Calibration according to different models for
quantitative multi-element-analysis using calibration samples,
calculation of concentration
- Special tools for LIBS-measurements
- Plasma temperature calculation
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ESAWIN-Temperature module:
This modul permits the determination of the
excitation temperatures of different atomes and
ions in plasma using the Boltzmann-Plot-Method. The
excitation conditions may vary between the singular laser pulses due to the
interactions between laser and sample surface, performing LIBS measurements.
The meaurement of the laser power characterizes the
energy provided by the laser, but the energy used for the creation of the
plasma is not determined. The plasma temperature can be used as an additional
criterion for the description of the stability of the excitation parameters.
Depending on the matrix and the measuring parameters the excitation
temperatures of different atoms and ions may vary.
The T-module is provded as dll-file
“t_module.dll”. Additionally, spectral line data are provided as text files
for almost al elements. The data represent an extract from the Kurucz-23-line
data (online version of Kurucz-database: 1995
Atomic Line Data (R.L. Kurucz and B. Bell) Kurucz CD-ROM No.23, Cambridge, Mass.:
Smithsonian Astrophysical Observatory). They fit the ROI-Files of LLA.
Demo software
The new demo version of ESAWIN software (Version 3.12) is available on CD.
Order your copy free of charge here
and do not forget your mail address. ESAWIN is used for control of
measurement and spectra processing at ESA 3000 and LIPAN.
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