LEED Auger Electronics Model AES-1
[available 3Q 2003]
This analog controller is intended for use with the PRI or PHI Model 11-020 LEED Electronics, and provides the additional voltages and control features needed to perform retarding field Auger analysis with any PRI or PHI LEED optics. A 3 1/2" high rack-mounted enclosure contains the control electronics and the high-voltage supplies. A lock-in amplifier and a plotter must be furnished by the user. A separate shielded box is provided to house the decoupling components between the lock-in amp and the collector. The unit includes:
- A beam voltage supply connecting to the External Beam Voltage input of the 11-020, with voltages of -1kV, -2kV, or -3kV, and a positive bias supply for the collector screen.
- A grid voltage supply that can be swept from zero volts to -2kV. The calibrated sweep rate is adjustable over a wide range, and the upper and lower limits of the sweep voltage are adjustable.
- A large 4 1/2 digit LED panel meter to display grid voltage.
- Three sweep modes: Single, Repetitive, and External. Controls allow the sweep to be stopped and/or restarted at any point. In External mode the sweep voltage can controlled by applying a +10VDC full-scale voltage from an external source (such as a PC-controlled DAC) to the External Input jack.
- A low-distortion audio oscillator and grid modulation transformer. Modulation frequencies from 250Hz to 5kHz at amplitudes from one to 20 volts peak to peak are available.
- Calibrated X-axis scale and offset controls for the output to the plotter and oscilloscope, enabling expanded scale examination of the Auger peaks. Scale can be expanded up to 10V/V, and the X axis zero point can be offset the equivalent of the full sweep voltage. A pen lift output raises the plotter pen at the end of a sweep and during setup.
- Outputs for oscilloscope monitoring of the Auger peaks at the higher sweep rates for easier set-up of the lock-in amplifier.
- A decoupling network in a shielded box for the collector output to the lock-in amplifier.
- Three cables with MHV plugs to connect the unit to the grids of the LEED, to the 11-020 controller, and to connect the decoupling box to the optics. A BNC cable is provided to connect the collector bias voltage to the decoupling box.
- An instruction manual and AC power cord.