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STB CIR events #17,19,20,22 are from period Dec 2007-Feb 2008 ( Bucik et al., AnGeo , 2009)

SIT-B 40-160 keV. STB CIR events #17,19,20,22 are from period Dec 2007-Feb 2008 ( Bucik et al., AnGeo , 2009) these two bursts periods show an excess in number of counts beyond 4He mass range compared to the CIR events

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STB CIR events #17,19,20,22 are from period Dec 2007-Feb 2008 ( Bucik et al., AnGeo , 2009)

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  1. SIT-B 40-160 keV • STB CIR events #17,19,20,22 are from period Dec 2007-Feb 2008 (Bucik et al., AnGeo, 2009) • these two bursts periods show an excess in number of counts beyond 4He mass range compared to the CIR events • the excess appears to be a bit larger in the magnetosphere (Feb 7-8) than in the solar wind (Mar 6-7) • is this a special ‘magnetosphere-related acceleration’ on solar wind which leads to the heavy ion enrichment ? • or other than solar wind population is accelerated ?

  2. SIT-B 80-160 keV • these additional counts during the bursts events are considerably reduced above 80 keV! • notice that in CIR histograms species like C, N, O and NeS are not resolved in this energy • range (or linear scale effect?)

  3. Fig.6 in Opitz et al., JGR, 2014; but G.M. Mason reports in the Aug 13, 2014 e-mail a contamination below 80 keV/n for NeS and Fe boxes.

  4. But these burst almost disappears above 80 keV !

  5. gray – counts from both bursts periods; red • – Dec 9 2007 CIR • count excess in 6-12 & 12-20 amu in slide 1 is • due to counts in 40-80 keV/n range; in CIRs there • are many counts in range 60-160 keV/n which masks • this excess in histograms on slide 1 • the shape of the 1st excess (6-12 amu) is due to • energy threshold and contains likely 4He ions • the 2nd excess (12-20 amu) should be due 16O • there is also small 3rdpeak due to NeS ions • since these bursts are low-energy phenomena • we luckily see O and NeS peaks! Therefore the • claiming in Opitz paper that enhancements in bursts • are seen in C-O range was correct. • for 40-80 keV/n the CIR and bursts histograms are • quite similar - implying common seed population • (solar wind)? • at higher energies (see last histogram which is • almost above the threshold energy for hydrogen ) • the H/He ratio in bursts is much different than in • the CIR – implying different acceleration processes ?

  6. previous CIR histograms in log scale 12C 16O 20Ne-32S no ‘so’ obvious peaks?

  7. BACKGROUND • ~20 min periodic bckg. feature, where: • 80-160 keV/n 4He counts shifted to higher amu (to C-O range) & • at higher energies (see 320-640 keV/n) when H counts start to appear, their counts also shifted to higher amu (like 3He) • such bckg. is not visible • above 20 amu and for 40-80 • keV/n – but not sure because counts are low (next slide checks this for a stronger event)

  8. now there are twoperiods • in the background • also this stronger event • shows that NeS, Fe & 40-80 • keV/n are not much affected by • this bckg.

  9. SIT-B bursts on top of CIR event 40-57 57-80 80-113 113-160 etc. 160-226 226-320 320-453 453-640 640-905 • why these bursts coincide with the periodic bckg. increases? But they are not bckg., • otherwise they appear always and it’s not the case! Would we see these bursts if SIT-B is • working without these periodic failures?

  10. … back to the G. Mason ‘s report on contamination < 80 keV/n • in this event, counts in gray area • (40-57 keV) behave differently than rest • energy ranges (especially at ~20-40 amu) • Fe peak is not well separated at • 40-57 but at 57-80 keV/n is separated • well

  11. 101-110 keV SEPT ions STEREO-A sunward pointing sensor anti-sunward pointing pattern similar to STB STEREO-B • the bursts pattern on STA until ~300Re (20 Jan) is similar to STB

  12. #1 #2 #3 #4 sunward pointing sensor anti-sunward pointing STA far (300 Re) from the bow shock ? STB almost at the bow-shock • STB shows more isotropic pattern while STA shows strong anisotropy spikes • in anti-sunward direction; strong simultaneous spikes #1,2,3,4 arrive from anti-sunward direction on STA but from sunward (or are more isotropic) on STB – placing their origin at the bow shock?

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