The Test and Analysis on Pulse Signal Detection Abilities of the X-ray Detector MCP for Pulsar Navigation

摘要

The Micro-Channel Plate detector (MCP) is an X-ray detecting system with a mature technology, which is suitable for space observation and navigation application of X-ray pulsar. For analyzing the X-ray pulse signal observation capability of MCP detector, a long-time experiment of MCP detector with different radiation flux and different background noise were carried out by the ground testing system. Meanwhile, a set of evaluation methods of the pulse observation capability of X-ray detector was established, those expressions of the signal-to-noise ratio (SNR), the correlation of pulse profile (R), the accuracy of pulse time of arrival {σ_(TOA)), the minimum detectable power (P_(nun)) are derived from the photon counting model of the ground testing system. In the whole testing experiment which took almost a week, 8 groups of 10000 s X-ray photon TOAs dataset were received by the 20 cm~2 MCP detectors, the best periods were searched and gained, the observable pulse profiles were replicated, those characteristic parameters of pulse profile were estimated. The result of this experiment shows that the MCP detector has a good,capability of X-ray pulse signal observation and reconstruction, the SNR, R, σ_(TOA) of the observed pulse profile at the low pulse signal flux (f_p = 0.05ph/cm~2/s) are (35.73, 88.38%, 51.53 μs) and are (35.73, 88.38%, 51.53 (is) at strong background noise (B = 16), so, the MCP detector has a good observation ability of a certain faint X ray pulsar. The result also has revealed that the minimum detectable power (P_(ram)) of MCP detector is closely related to the power intensity of the X-ray pulsar simulator, is less correlation with the intensity of background noise. The P_(min) has the minimal value which is also called the minimum detectable cutoff power. When the X-ray pulse signal received by MCP detector is weak, P_(ram) is close to its minimal value (1 × 10~(-14) W).