Run 9 BSMD Calibration

Parent page for BSMD Run 9 Calibration

01 Status of BSMDE,P at the end of pp 500 GeV run, April of 2009

Summary of BSMD performance on April 6. Input : 200K events tagged by L2W clust ET>13 GeV, days 85-94, ~all events, only ZS data are shown.


Attached PDFs shows zoom in spectra for individual modules. 1st page is summary, next I show 3 modules per row, 5 rows per page. Even pages shows zoom-in for low ADC<100, odd pages shows full ADC scale. Common maxZ=1000 is used for all plots , except page 1. 

02 offline QA of BSMD pp 500, ver1 (Willie+Jan)

 BSMD QA algorithm and results for pp 500, tune optimized for high energy  energy response

  1. QA method, details are given in Willie's blog
    Fig 1. Typical good/bad strips from the E-plane and with wide pedestals. 
    • Input: all available events from fills 10399, 10402, 10403, 10404, 10407, 10412, 10415 added together
    • evaluate shape of pedestal residua for  NZS data captured on-line by Willie's daq reader  (Blue filled histo)
    • evaluate yield in high energy range (ADC ~300,500,800) using ZS data from L2W triggered events (Magenta line-only)
    • ignored: satellite spikes around  pedestal at ADC ~32, those come from correlated noise and (most likely) such events will be discarded.
    • Example of such spectra for few strips is shown in fig 1.
    • Encoding of BSMD status bits extends existing convention to use LSB=1 for good strips and LSB=0 for bad strips. We used bits 1,2,3 to tag pedestal problems and bits 5,6,7 to tag yield problems. 
    • More plots with individual strips is in attachment A,B,C,D.
  2. Bad strip is defined as having : bad pedestal or god pedestal but no yield above it.

    Fig 2. Distribution of bad strips from both planes, details about each plane separately is in attachment E.
  3. The remaining issues:
    1. of tagging 'spiked' events (or modules?) needs to be investigated.
    2. study time dependence
  4. For the reference this directory contains PDF files with plots from all 120 BSMD modules.

 

Fig 3. # of bad strips per module.

 

03 correlated, small ADC spikes in BSMD (Jan)

Study of small ADC spikes in BSMD 

Input:

  •  all available events from fills 10399, 10402, 10403, 10404, 10407, 10412, 10415 added together
  • pedestal residua for  NZS data captured on-line by Willie's daq reader  (Blue filled histo)
  •  ZS data from L2W triggered events (Magenta line-only)

The following plots support those observation:

  1. spikes are symmetric on both sides of pedestals peak, separated by 2^N ADC counts, narrower than pedestal peak, (Fig1)
  2. spikes are correlated in even ID (or odd) strips the same plane, correlation is local, Fig 2 
  3. spikes are correlated between P-plane & E-plane strips, Fig 3
  4. energy deposit in BSMD increases probability of spikes, see peak/valley for blue vs. magenta in fig 1b.
  5. bands are visible at larger ADC, as shown by Oleg, not sure what data and how many events, fig 4 
  6. perhaps fig 1c shows yet another pathology, because it does not obey odd/even rule in fig 1a & 1b.

 

Fig 1a. Example of spikes delADC=16, in the vicinity of strip 1525-P, all strips from module 11 are shown in attachment A.

Fig 1b. Example of spikes delADC=32, in the vicinity of strip 1977-P, all strips from module 14 are shown in attachment B, module 22 looks similar.

Fig 1c. Example of spikes delADC=128, in the vicinity of strip 4562-P, all strips from module 31 are shown in attachment C, modules 51,52,57  look similar

Fig 2. Phi-Phi plane correlation of P-strip 1979 with (odd)  P-strips: 1977..1994. Attachment D contains correlation of P-strips [1977-80] with  24  strips in proximity. 

Fig 3. Phi-Eta plane correlation of P-strip 1979 with (odd)  E-strips: 1977..1994. Attachment E contains correlation of P-strips [1977-80] with  24  strips in proximity. 

 

Fig 4.Oleg observed this stripes in raw BSMD ADC spectrum, not sure what data.

2009 BSMD Relative Gains Information

The pdf posted here has a good overview of the computation of the slope for each strip, discussing the method and the various ways in which strips were marked as bad.  This page discusses the computation of the actual relative gains and statuses that went into the database.

The code used to compute the relative gains is archived at /star/institutions/mit/wleight/archive/bsmdRelGains2009/.

DELETE - Run 9 BSMD Status Update 3 (4/24)

After looking more closely at the crate 1 channels I was forced to make serious revisions to status bit 2 from the previous update.  The new status bit 2 test is as follows:

First, I scan through the strip ADC distribution looking for peaks.  A peak is defined as a channel that is greater than or equal to the four or two channels to either side (if the sigma of the fit to the strip ADC distribution is greater than or less than six, respectively), has a content that is greater than 5% of the maximum of the strip ADC distribution, and has a depth greater than 5% of the maximum of the strip ADC distribution.  The depth is calculated by first calculating the difference between the peak content and the channel content for each of the four or two channels on either side of the peak.  The maximum of these differences is obtained for the left and right sides separately, and the depth is then equal to the lesser of these two maxima.

If the strip has more than one peak and the maximum of the depths is greater than 20% of the maximum of the strip ADC distribution, then the strip is given bad status 2.  If the strip has only one peak (which is then necessarily the maximum of the entire distribution) but the distance between that peak and the peak obtained from the gaussian fit is greater than 75% of the sigma from the gaussian fit, the strip is given bad status 2 as well.  Attached is a pdf that has only the pedestal plots for all channels from crate 1.

Edit: I forgot that the BSMD crates don't increase with module number: what is labeled as crate 1 is actually crate 2, as that is the crate that has the first 15 modules, and the attachment labeled as crate 2 is the 2nd 15 modules and so actually crate 1.

2nd edit: This is now out of date, please see the new update.

DELETE - Run 9 BSMD Status Update 4 (4/27)

After further investigations -- specifically looking at strips that had a significant secondary peak, entirely separated from the main peak, with a max of ~40, which were not being caught by my cuts -- I have again revised my criteria for status bit 2.  Again, I begin by looking for peaks.  If a peak candidate is less than three sigma from the peak of the strip ADC distribution (strip and peak both taken from the gaussian fit), the same cuts are imposed: the candidate must be greater than the four (if sigma>6) or two (if sigma<6) channels on on either side of it, it's content must be greater than 5% of the maximum of the strip ADC distribution, and the depth must be at least 5% of the maximum of the strip ADC distribution.  If the strip has two such peaks with the maximum of the depths greater than 20% of the maximum of the strip ADC distribution, or has only one peak but that peak is at least one sigma away from gaussian fit peak, it is given bad status 2.  Note the only change here is that the previously a strip with only one peak could be marked bad if it was 75% of sigma away from the gaussian fit peak.

Most of the changes have to do with candidates that are at least three sigma from the gaussian fit peak.  In this case the cuts are relaxed: the bin content need only be .5% of the max, not 5%, though it still must be at least 10, and the peak depth is required to only be at least 5% of the peak itself, not of the max.  A more than three-sigma peak has the same requirements for the number of channels it must be greater than: however, none of those channels can have value 0.  Any strip with a candidate that passes these criteria is automatically given bad status 2. 

Pdfs for crates 1 and 2 are attached (but note that the crate 1 and crate 2 pdfs contain the first and second 15 modules, respectively, and therefore crate 1 should actually be labeled crate 2 and crate 2 is really crate 4).

DELETE - Run 9 BSMD Status Update 5 (4/30)

Edited on 5/1 to reflecte new status bit assigments for bits 3 and 4.

The current BSMD status bits are as follows:

Bit 2: Bad pedestal peak/multiple pedestal peaks.  This is described in more detail here.  Examples can be found in crate2_ped.pdf pp 207 and 314 and crate4_ped.pdf p 133.

Bit 3: Pedestal peak has bad sigma, sigma<1 or sigma >15

Bit 4: Chi squared value from gaussian fit is greater than 1000 (i.e., pedestal has a funny shape)

Bit 5: Strip is exactly identical to the previous strip

Bit 6: The ratio of the integral of channels 300-500 to the total integral does not fall between .0001 and .02

Bit 7: The ratio of the integral of channels 500-800 to the total integral does not fall between .00004 and .02

Bit 8: The ratio of the integral of channels greater than 800 to the total integral does not fall between .00005 and .02

Note that this means that dead channels have status 111xxxx0->448 (or greater).

The attached pdfs crate2 and crate4.pdf have the pedestal distributions, taken from NZS data, and the overall distributions, taken from ZS L2W data, overlayed; crate2_ped and crate4_ped.pdf have only the pedestal distributions.  The NZS data used was taken from my monitoring for fills 10415-10489.  The L2W data came from fills 10383-10507.  Additionally, at the beginning of each module is a summary page that has plotted the distributions for the ratios used to determine bad status bits 6, 7, and 8, and the overal distribution of status vs. strip for eta and phi.

Finally, there are a couple of possible new problems.  Page 18 in crate4_ped.pdf has several examples of pedestal distributions that have shoulders.  Page 20 has a few examples of pedestal distributions with a small, skinny peak perched on top of a large, broad distribution.  At the moment I have no bad status bit for either of these, and any peak with either of these features would almost certainly not be marked bad (even though I did manage to catch one of the ones on page 20).

Edit: Scott suggested during the phone meeting today that perhaps the problem of a small peak on a broad distribution was due to time variation of the pedestal width, and in the plot below you can see that he was correct: the strip initially has an extremely wide pedestal which then shrinks down suddenly.  Futhermore, looking at one of the strips that had a sort of shoulder to it, you can see that this is just a less-pronounced version of the double peak problem seen before: the pedestal goes up by 10 for a much shorter time frame, thus producing a shoulder rather than a second peak.  This suggests that, as Scott said, these channels should still be usable, and that once we begin breaking status down by time these funny shapes should be less of a problem.

DELETE - Run 9 BSMD Status Update 6 (5/4)

As Matt says that the maximum status is 255, I have dropped the old status bit 5 as (it was unused).  Also, I have loosened the dead strip cuts based on looking at module 55 (see pages 203 or 205 in the attached crate1.pdf, for instance).  The status bits are now as follows:

Bit 2: Bad pedestal peak/multiple pedestal peaks.

Bit 3: Pedestal peak has bad sigma, sigma<1 or sigma >15

Bit 4: Chi squared value from gaussian fit is greater than 1000 (this applies only for strips that do not have bad status 2 already)

Bit 5: The ratio of the integral of channels 300-500 to the total integral does not fall between .0005 and .02

Bit 6: The ratio of the integral of channels 500-800 to the total integral does not fall between .0002 and .02

Bit 7: The ratio of the integral of channels greater than 800 to the total integral does not fall between .0002 and .02

Below is a plot of status vs. eta and phi for BSMDE and BSMDP strips.  Note that strips with all three of bits 5, 6, 7 bad (generally, dead strips) are given the value 8 in this plot to distinguish them from strips that may have just one of those bits bad.  As some strips may have more than one bad status bit, for clarity I ranked the potential bad statuses in the order 2, 8, 7, 6, 5, 4, 3 (i.e., approximately in order of importance) and plotted for each strip only the highest-ranked status.

 

Additionally, I found a problem I had not seen before.  On page 207 of the attached crate1.pdf you can see that in the L2W data some strips have a large peak out in the tail of the ADC distribution.  However, as all these strips are caught by my code it's not a serious problem.

Final Run 9 200 GeV BSMD Status

In essence, the 200 GeV status tables were calculated the same way as the 500 GeV tables were.  Please see here for details.

Final Run 9 500 GeV BSMD Status - Willie Leight

BSMD Pedestals and Status for Run 9 pp 500 Data (June 2009, uploaded to offline DB)

The BSMD status analysis for the 500 GeV data proceeds as follows:

  1. Each strip is assigned a status for the whole run from an analysis of fills 10399, 10402, 10403, 10404, 10407, 10412, and 10415.  Pedestals are analyzed using NZS data taken by the BSMD online monitoring, which reads NZS data from evp and subtracts off pedestals which are updated each time a new BSMD pedestal run is taken.  Because NZS data is essentially minbias, high energy tails are analyzed using L2W-triggered data.  Status bits are described in detail here. 
  2. Once each strip has an assigned status, those strips that are not marked as bad move on to the second step.  Here the strips are examined fill-by-fill: for each fill the strip pedestal is QAed by re-applying the pedestal cuts (but not the tail cuts due to lack of statistics), and a new status for that fill is determined.
  3. Next, a pedestal correction is calculated.  The pedestal correction is just the MPV of the pedestal residua if the MPV is greater than the RMS of the pedestal residua. 
  4. Finally, we upload a number of tables to the database: for each BSMD plane there is one that contains a universal status for every strip, one for each fill containing a status for every strip, and one for each fill containing the RMS and pedestal correction for every strip. 

Attached is a pdf that presents the results of this study, including examples.

All code and root files are archived at /star/institutions/mit/wleight/archive/2009-pp500-bsmdStatus/.

Table 1: Pedestal correction, RMS, and status vs. fill for each module (Crates 1-4 are the West Barrel)

Cr 1 Mod 46 Mod 47 Mod 48 Mod 49 Mod 50 Mod 51 Mod 52 Mod 53 Mod 54 Mod 55 Mod 56 Mod 57 Mod 58 Mod 59 Mod 60
Cr 2 Mod 1 Mod 2 Mod 3 Mod 4 Mod 5 Mod 6 Mod 7 Mod 8 Mod 9 Mod 10 Mod 11 Mod 12 Mod 13 Mod 14 Mod 15
Cr 3 Mod 31 Mod 32 Mod 33 Mod 34 Mod 35 Mod 36 Mod 37 Mod 38 Mod 39 Mod 40 Mod 41 Mod 42 Mod 43 Mod 44 Mod 45
Cr 4 Mod 16 Mod 17 Mod 18 Mod 19 Mod 20 Mod 21 Mod 22 Mod 23 Mod 24 Mod 25 Mod 26 Mod 27 Mod 28 Mod 29 Mod 30
Cr 5 Mod 61 Mod 62 Mod 63 Mod 64 Mod 65 Mod 66 Mod 67 Mod 68 Mod 69 Mod 70 Mod 71 Mod 72 Mod 73 Mod 74 Mod 75
Cr 6 Mod 76 Mod 77 Mod 78 Mod 79 Mod 80 Mod 81 Mod 82 Mod 83 Mod 84 Mod 85 Mod 86 Mod 87 Mod 88 Mod 89 Mod 90
Cr 7 Mod 91 Mod 92 Mod 93 Mod 94 Mod 95 Mod 96 Mod 97 Mod 98 Mod 99 Mod 100 Mod 101 Mod 102 Mod 103 Mod 104 Mod 105
Cr 8 Mod 106 Mod 107 Mod 108 Mod 109 Mod 110 Mod 111 Mod 112 Mod 113 Mod 114 Mod 115 Mod 116 Mod 117 Mod 118 Mod 119 Mod 120

 

Table 2: BSMD spectra for 150 eta and 150 phi strips used for status determination for each module (for fills listed above).  Bad strips are identified with the status (in hex): strips with red status are marked bad, strips with green failed a cut but are not necessarily bad.  Note that these spectra are shifted up by 100 on the X-axis so that the pedestal is centered around 100 rather than 0.

Cr 1 Mod 46 Mod 47 Mod 48 Mod 49 Mod 50 Mod 51 Mod 52 Mod 53 Mod 54 Mod 55 Mod 56 Mod 57 Mod 58 Mod 59 Mod 60
Cr 2 Mod 1 Mod 2 Mod 3 Mod 4 Mod 5 Mod 6 Mod 7 Mod 8 Mod 9 Mod 10 Mod 11 Mod 12 Mod 13 Mod 14 Mod 15
Cr 3 Mod 31 Mod 32 Mod 33 Mod 34 Mod 35 Mod 36 Mod 37 Mod 38 Mod 39 Mod 40 Mod 41 Mod 42 Mod 43 Mod 44 Mod 45
Cr 4 Mod 16 Mod 17 Mod 18 Mod 19 Mod 20 Mod 21 Mod 22 Mod 23 Mod 24 Mod 25 Mod 26 Mod 27 Mod 28 Mod 29 Mod 30
Cr 5 Mod 61 Mod 62 Mod 63 Mod 64 Mod 65 Mod 66 Mod 67 Mod 68 Mod 69 Mod 70 Mod 71 Mod 72 Mod 73 Mod 74 Mod 75
Cr 6 Mod 76 Mod 77 Mod 78 Mod 79 Mod 80 Mod 81 Mod 82 Mod 83 Mod 84 Mod 85 Mod 86 Mod 87 Mod 88 Mod 89 Mod 90
Cr 7 Mod 91 Mod 92 Mod 93 Mod 94 Mod 95 Mod 96 Mod 97 Mod 98 Mod 99 Mod 100 Mod 101 Mod 102 Mod 103 Mod 104 Mod 105
Cr 8 Mod 106 Mod 107 Mod 108 Mod 109 Mod 110 Mod 111 Mod 112 Mod 113 Mod 114 Mod 115 Mod 116 Mod 117 Mod 118 Mod 119 Mod 120

 

Table 3: Fills used in this study.

#      Fill        Date          Begin run      End run   LT/pb
1 F10383 2009-03-18 R10076134 R10076161 0.00
2 F10398 2009-03-20 R10078076 R10079017 0.08
3 F10399 2009-03-20 R10079027 R10079086 0.22
4 F10402 2009-03-21 R10079129 R10079139 0.04
5 F10403 2009-03-21 R10080019 R10080022 0.01
6 F10404 2009-03-22 R10080039 R10080081 0.09
7 F10407 2009-03-22 R10081007 R10081056 0.05
8 F10412 2009-03-23 R10081096 R10082095 0.23
9 F10415 2009-03-24 R10083013 R10083058 0.24
10 F10426 2009-03-25 R10084005 R10084024 0.11
11 F10434 2009-03-26 R10085016 R10085039 0.18
12 F10439 2009-03-27 R10085096 R10086046 0.26
13 F10448 2009-03-28 R10087001 R10087041 0.29
14 F10449 2009-03-28 R10087051 R10087097 0.32
15 F10450 2009-03-29 R10087110 R10088036 0.29*
16 F10454 2009-03-29 R10088058 R10088085 0.15*
17 F10455 2009-03-30 R10088096 R10089023 0.29*
18 F10463 2009-03-31 R10089079 R10090027 0.20*
19 F10464 2009-03-31 R10090037 R10090047 0.08*
20 F10465 2009-03-31 R10090071 R10090112 0.13*
21 F10471 2009-04-02 R10091089 R10092050 0.30
22 F10476 2009-04-03 R10092084 R10093036 0.28
23 F10478 2009-04-03 R10093057 R10093085 0.08
24 F10482 2009-04-04 R10093110 R10094024 0.55
25 F10486 2009-04-05 R10094063 R10094099 0.52
26 F10490 2009-04-05 R10095019 R10095057 0.40
27 F10494 2009-04-06 R10095120 R10096027 0.61
28 F10505 2009-04-07 R10096139 R10097045 0.39
29 F10507 2009-04-08 R10097086 R10097153 0.29
30 F10508 2009-04-08 R10098029 R10098046 0.17
31 F10517 2009-04-09 R10099020 R10099078 0.32**
32 F10525 2009-04-10 R10099185 R10100032 0.68
33 F10526 2009-04-10 R10100049 R10100098 0.37
34 F10527 2009-04-11 R10100164 R10101020 0.82
35 F10528 2009-04-11 R10101028 R10101040 0.31
36 F10531 2009-04-12 R10101059 R10102003 0.86
37 F10532 2009-04-12 R10102031 R10102070 0.76
38 F10535 2009-04-13 R10102094 R10103018 0.86
39 F10536 2009-04-13 R10103027 R10103046 0.43

* Crate 2 was off for this fill

** This fill had no BSMD data

Final Run 9 BSMD Absolute Calibration

The Run 9 BSMD absolute calibration was made using few-GeV TPC-identified electrons from pp500 running, and has two pieces.  The first is a new CALIBRATION table in the database which will be used in the EMC slow simulator to improve the agreement of of MC ADC with data.  This table starts by combining the previously-determined strip-by-strip relative gains with the existing values in the table.  This is then multiplied by the ratio of the slope of a linear fit to the mean cluster ADC distribution from few-GeV isolated data electrons to the same slope in simulated electrons, where the slope is calculated in four different eta bins.  The second piece is a new GAIN table in the database which allows ADC values to be converted to energy deposited in the BSMD.  This table was determined by combining the strip-by-strip relative gains with a similar ratio as above, but using mean cluster energy deposited in the BSMD instead of reconstructed ADC values (the electron samples used for data and MC were the same) and it is calculated in ten eta bins instead of four.  Both tables are currently in the database with flavor "Wbose2": it is hoped that eventually the CALIBRATION table will migrate to flavor "ofl", but the GAIN table will have to remain "Wbose2" because it is currently used (with values all equal to 1) in some codes to determine the change in the BSMD calibration over time.  While producing two tables which are in some ways overlapping and one of which can never be flavor "ofl" is not an ideal solution, it allows us to avoid making any modifications to currently existing code (in particular the StEmcSimulator) and allows people who prefer to think of reconstructed energy from BSMD ADCs as being the full particle energy instead of the energy deposited in the BSMD to continue as they were with no change.  For more details, please see:

1. Overview of the method

2. Final cut list and data-MC comparison

3. Overall Summary

Additionally, a link to the 2009 BSMD Calibration note will be added here once it is completed.

See also a brief presentation on why we chose not to include the BSMD gas pressure in our analysis.

Run 9 BSMD Status Update 1 (4/19)

I use two datasets to QA BSMD channels: zero-suppressed data from L2W events (fills 10383-10507) and non-zero-suppressed data from online monitoring (fills 10436-10507) (note that at the moment I am not examining the time dependence of BSMD status).  NZS data is used to QA the pedestal peak of a channel, while high-energy ZS data is used to QA the tail.

Next, the ZS data are compared to the ZS data from the previous channel to check for copycat channels.  Then three quantities are calculated: the ratios of the integrals from 300-500, 500-800, and 800-the end of the spectrum to the total integral of the channel.  Each of these quantities must then fall within the following cuts: .0001-.02, .00004-.02, and .00005-.02 respectively.  Here is a sample distribution:

Also, the spectra for the strips in module 3, with status, are attached.  I have not had a chance to look closely at any other modules yet.