The PHA distribution differs for the three hotspots.
| HS #1 | #2 | #3 | |
| 85% in channel 1 | peaks in channel 1; | peaks in chs. 2 or 3; | |
| 15% in channel 2 | then decreases with | close to zero for | |
| <1% in channel 3 | about 1/2 counts | ch. 5 and above | |
| in channels 4-10. |