
Chapter 1 Introducing the Voyager™ Biospectrometry™ Workstations
1-22 PerSeptive Biosystems
1
Parts of the mass
spectrometer
The Voyager-DE and Voyager-DE PRO mass spectrometers
include:
• Laser, attenuator, and prism—A nitrogen laser that
operates at 337 nm and ionizes sample. It produces
3-nanosecond-wide pulses (factory set to 3 Hz). Laser
rate is not user-settable.
The laser attenuator varies the intensity of the laser beam
reaching the sample.
The prism deflects the laser beam into the ion source.
• Ion Source—A high voltage region used to accelerate
ions. Includes:
• Sample plate and sample stage—An area
supplied with voltage (0 to 25,000 V) for
acceleration of ions into the flight tube.
• Variable-voltage grid—A grid supplied with
additional voltage to fine-tune ion acceleration.
• Ground grid—Ground surface for formation of
potential gradient.
• Grounded aperture—Entrance to flight tube.
For more information on the ion source and voltages, see
Section 5.4.4.2, Setting Accelerating Voltage, and
Section 5.4.3.5, Optimizing Grid Voltage%.
• Video camera—A camera that displays a real-time
sample image (25 times magnification) on the video
monitor.
• Vacuum system—A pumping system and sealed
enclosure that creates and maintains a high-vacuum
environment for unobstructed ion drift. Refer to
Section 1.5.3, Vacuum System, for more information.
• Flight tube and beam guide wire—A field-free region
(no additional accelerating forces are present) in which
ions drift at a velocity inversely proportional to the square
root of their masses. The voltage applied to the beam
guide wire overcomes the dispersion effect from the ion
source and refocuses ions on the detector.
Kommentare zu diesen Handbüchern