| k. Gas Ionization Detector | » Back to a |
| A gas ionization detector analyzes the ions emerging
from the last bending magnet. In this final device, particles are
identified by their energy loss due to the fact that the stopping
power for particles in matter is dependent on the number of protons
in the ion's nucleus. By adjusting the gas pressure in the detector,
the 14C ions are "selected". The ionization-charge
pulses they generate in the gas are proportional to their energy.
These individual charge pulses are collected and counted in the AMS
detector electronics.
The raw result of the AMS analysis is the ratio of 14C particles per second detected in the ionization chamber to the particle currents measured in the Faraday cups (h). This ratio is compared with frequently measured ratios of known "standards" to arrive at the final AMS result. |
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