HFI-bottom up

Like all experiments, Planck/HFI had a number of "issues" which it needed to track and verify were not compromising the data. While these are discussed in appropriate sections, here we gather them together to give brief summaries of the issues and refer the reader to the appropriate section for more details.

• Cosmic Rays - Unprotected by the atmosphere and more sensitive than previous bolometric experiment, HFI was subjected to many more cosmic ray hits than previous experiments. These were detected, the worst parts of the data flagged as unusable, and "tails" were modeled and removed.
• Elephants
• 1.6 K Stage Fluctuations
• 4 K Stage Fluctuations
• Popcorn Noise
• Jumps
• 4 K Cooler-Induced EM Noise
• 4 K Cooler-Induced Microphonics
• Pointing-Change Microphonics
• Compression
• Noise Correlations
• Electrical Cross-Talk

• Pointing
• Focal Plane Geometry
• Main Beam
• Ruze Envelope
• Dimpling
• Far Sidelobes
• Planet Fluxes
• Point Source Fluxes

• Time Constants
• ADC Correction
• Gain changes with Temperature Changes
• Optical Cross-Talk
• Bandpass
• Saturation