Difference between revisions of "CDC q vs n"
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− | Run 11559 cosmics April 20. | + | <h2>Run 11559</h2> cosmics April 20. |
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|[[Image:cdc_run11559_qn.png|thumb|x200px|MPV of Landau fitted to DCDCHit->q for each straw, low gain straws (from hvb I22) in red]] | |[[Image:cdc_run11559_qn.png|thumb|x200px|MPV of Landau fitted to DCDCHit->q for each straw, low gain straws (from hvb I22) in red]] | ||
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− | Run 10496 | + | <h2>Run 10496</h2> |
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|[[Image:cdc_run10496_qn.png|thumb|x175px|Run 10496 30nA beam on diamond Feb 24]] | |[[Image:cdc_run10496_qn.png|thumb|x175px|Run 10496 30nA beam on diamond Feb 24]] | ||
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+ | {| border="0" cellpadding="2" | ||
+ | |[[Image:cdc_run10496tfit.png|thumb|x70px|drift time fit, max drift time 656ns]] | ||
+ | |} | ||
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+ | <h2>Run 10777</h2> | ||
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|[[Image:cdc_run10777_qn.png|thumb|x260px|Run 10777 100nA beam on diamond Mar 6]] | |[[Image:cdc_run10777_qn.png|thumb|x260px|Run 10777 100nA beam on diamond Mar 6]] | ||
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+ | <h2>Run 11667</h2> | ||
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|[[Image:cdc_run11667_qn.png|thumb|x190px|Run 11667 112nA beam on diamond April 25 after increasing low-gain preamp LV]] | |[[Image:cdc_run11667_qn.png|thumb|x190px|Run 11667 112nA beam on diamond April 25 after increasing low-gain preamp LV]] | ||
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+ | {| border="0" cellpadding="2" | ||
+ | |[[Image:cdc_run11667tfit.png|thumb|x70px|drift time fit, max drift time 672ns]] | ||
+ | |} | ||
Low gain straws were n=3064 to 3070, 3270 to 3277, 3479 to 3277 | Low gain straws were n=3064 to 3070, 3270 to 3277, 3479 to 3277 |
Revision as of 14:58, 9 May 2016
Contents
Run 11559
cosmics April 20.The above plot is the MPV of a Landau fitted to q for each straw vs straw number; straw numbers start with 1 in the innermost ring, beam left, and increase clockwise around the ring and then out to the next ring, etc. The low gain straws (red) are near the bottom of the CDC.
- The slight upward trend in q vs n (straw number) can also be seen in the plots of amplitude and q for rings 1 and 28.
- The oscillations may be an artefact of the fitted Landau MPV moving with the data count in the histogram.
- The troughs in the hit count correspond to troughs in the fitted MPV for q. ???
- The pedestal and amplitude vs n plots do not show huge oscillations, except in number of hits.
- There is a clear oscillation in the hit count vs straw number, which peaks at the sides of the CDC. This is because the mostly vertical cosmic ray tracks pass through many straws at the sides, but only a few above and below. The oscillations should not be present with beam data (but the data probably includes some cosmics).
To-do:
- Repeat with more data
- Use track info - ignore untracked hits
- Pick cosmics out of beam data?
- Beam data oscillations are more sawtooth than sine, why?
- Look at drift times
Run 10496
Run 10777
Run 11667
Low gain straws were n=3064 to 3070, 3270 to 3277, 3479 to 3277