All,

While working on the final processing of the observed CRaTER Flux vs. LET data, I have found an interesting artifact.

I have been looking at the Flux vs. LET vs Time data for the entire mission so far.

• For the smallest LET values, there seems to be a 6-month periodicity in the observed flux, see the ‘wavy’ red edge in Figure 1 below.
• When I divide everything by the flux observed in August 2009, I get the flux ratio shown in Figures 2 and 3 below. When looking at the flux ratio, the 6 month periodicity becomes very clear.
• One interesting thing I also notice is that it seems like there is an anti-correlation between the flux in lowest LET bins (< 0.25 keV/micron) and the slightly higher LET bins  (> 0.25 keV/micron).

Has anyone else observed this yet? Any thoughts about what is causing this?

Thanks,

Wouter

Figure 1: Flux vs. LET vs. Time

Figure 2: Flux Ratio vs. LET vs. Time (3-Dimensioal)

Figure 3: Flux Ratio vs. LET vs. Time (2-Dimensioal)