Pp. Manning et al., A FAST AND FLEXIBLE MULTICHANNEL ELECTRON DETECTOR WITH PARALLEL READOUT FOR PHOTOELECTRON-SPECTROSCOPY, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 392(1-3), 1997, pp. 345-348
To satisfy end user requirements for higher throughput and reliability
in photoelectron spectroscopy, a new multichannel electron detector w
ith discrete electronics has been designed and commissioned at Daresbu
ry Laboratory. Count rate performance has been enhanced by the use of
low resistance microchannel plates which amplify the electron pulses i
ncident on the anode array. The low resistance microchannel plates are
linear to 2.5 x 10(4) s(-1)mm(-2) for a bias voltage of 900 V per pla
te, providing more than an order of magnitude improvement in count rat
e performance over high resistance microchannel plates, microchannel p
late outgassing in the ultra-high vacuum environment limits the scale
of this improvement. A novel anode design maximizes the collection eff
iciency, while minimising crosstalk between channels (< 0.6% after dis
crimination) and provides up to 40 parallel channels on a 1 mm pitch.
The collection efficiency is increased from 50% to 70% (for the presen
t geometry) by applying a 50 V bias between the guard rail and electro
des on the anode. Each data collection channel comprises a fast curren
t amplifier and discriminator, capable of a throughput of 2.5 x 10(7)
s(-1), and a 24 bit scaler. The integral non-linearity for flat-field
illumination is better than 10% with no correction. The fast multichan
nel detection system gives a throughput enhancement of 10-20 on single
-channel detection systems. It has also proved to be significantly bet
ter than previous multichannel detection systems with discrete electro
nics due to its high throughput, modular design and flexible structure
.