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MCA-1K Morpho Data Server Reference |
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MCA-1KUSB driverData structuresARM Data structuresAPI |
MCA-1K Data Structure: arm_histogram, arm_bck, arm_diffSummaryThere are two memory banks for MCA data, ie containing statistics from which to compute elapsed time and count rate and, of course, the histogram data. Both banks are identical and have 1040 entries, 16 statistics and 1024 histogram words; all are 32-bit wide. A user may simply acquire a histogram in bank_0 and read data from there. This is the foreground or sample histogram, where the word sample indicates a piece of material whose radioactivity you want to measure. In this case you read from arm_histogram. Alternatively, one can first acquire a natural background spectrum into bank_1 for a while. Then the user would place a sample in front of the detector and acquire the sample or foreground spectrum. In this case, use arm_bck to read back the background spectrum, and use arm_diff to read the background-subtracted fore-ground spectrum. Note that the acquisition times for the foreground and background spectrum are allowed to be different. All three data structures have (almost) exactly the same format. The structure arm_diff uses signed integers, because the foreground-background spectrum may have negative entries, due to shielding by the sample and counting statistics. MCA structuresFor arm_histogram, arm_bck, and arm_diff there are 1040 data in use. All register data are 32-bit integers; arm_histogram, arm_bck use uint32 while arm_diff uses int32 (signed).
These are the higher-level 'user' dictionary entry for arm_histogram.
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