Difference between revisions of "Resolutions"

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* 90/10 worse because shorter drift times.
 
* 90/10 worse because shorter drift times.
 
* Model contains:
 
* Model contains:
−
** Timing resolution
+
** Timing resolution (0.75 length of time sample)
−
** accuracy
+
** accuracy  
−
** diffusion
+
** diffusion (Garfield)
  
 +
 +
* Table with resolutions for straw 7 and different clock settings:
 +
** high: with hit removed from tracking
 +
** low: with hit included
 
{| border="1"  
 
{| border="1"  
 +
|-
 
| Distance from wire [mm]
 
| Distance from wire [mm]
−
|| Resolution (low) [um]
+
!colspan="2"| Resolution (low) [um]  
−
|| Resolution (high [um]
+
!colspan="2"| Resolution (high [um]
 
|-
 
|-
 
|  
 
|  
Line 54: Line 59:
 
| 125 MHz
 
| 125 MHz
 
| 200 MHz
 
| 200 MHz
 +
|-
 +
| 0-1
 +
| 388
 +
| 394
 +
| 404
 +
| 396
 +
|-
 +
| 1-2
 +
| 346
 +
| 292
 +
| 346
 +
| 205
 +
|-
 +
| 2-3
 +
| 209
 +
| 191
 +
| 222
 +
| 210
 +
|-
 +
| 3-4
 +
| 142
 +
| 135
 +
| 166
 +
| 165
 +
|-
 +
| 4-5
 +
| 118
 +
| 96
 +
| 164
 +
| 151
 +
|-
 +
| 5-6
 +
| 85
 +
| 88
 +
| 148
 +
| 164
 +
|-
 +
| 6-7
 +
| 67
 +
| 70
 +
| 165
 +
| 174
 +
|-
 +
| 7-8
 +
| 65
 +
| 63
 +
| 158
 +
| 169
 +
|}
 +
 +
 +
* The difference between high and low is largest for 1-3 mm driftdistances but overall the difference is not that big.
 +
* Gas mixture has a big impact
 +
* We might not have a big enough lever arm:
 +
{| border="1" cellpadding="2"
 +
|-
 +
|width="415pt"|[[Image:endplate.jpg|thumb|none|400px|Drawing of the end plate of the small prototype.]]
 +
|-
 +
|}
 +
 +
 +
= GARFIELD - DATA =
 +
 +
Below 70/30 gas mixture ch 7: left MC, right data
 +
 +
{| border="1" cellpadding="2"
 +
|-
 +
|width="415pt"|[[Image:res7mc.jpg|thumb|none|400px|Resolutions as a function of drift distance (MC).]]
 +
|width="415pt"|[[Image:res7data.jpg|thumb|none|400px|Resolutions as a function of drift distance (data).]]
 +
|-
 
|}
 
|}
  
 +
= To do =
  
−
  [2|| This is a table with a single cell on the first line  ||
+
* There is a full simulation of the chamber and results are on there way
−
  ||  two cells          || on this line                    ||
+
* We are testing 80/20 gas right now
−
  ||  two cells on      || this line too                  ||
+
* We want to test the same gas mixture as FDC uses
−
  |||> and one centred cell on this line                    |]
+
* We also want to try and add ethane
 +
* Try different timing algorithms
 +
* Find a way to extract the timing resolution directly

Latest revision as of 15:55, 23 July 2009

Prelude

  • Two gases are used: 70/30 and 90/10 Ar/CO2
  • Two fADC clock settings are used: 125 and 200 MHz
  • Drift time spectra (DCOG method is used):
90/10 Ar/CO2 drift time spectra.
70/30 Ar/CO2 drift time spectra.
  • Red line is fit to get absolute minimal drift time
    • Best tracking results if extracted minimal drift time + 1 time sample
  • Samples per rising edge - 2 extra samples 125 -> 200 MHz
Samples/rising edge - 70/30 Ar/CO2 - 125~MHz clock.
Samples/rising edge - 70/30 Ar/CO2 - 200~MHz clock.
  • Time-2-distance relation:
    • GARFIELD is used. To get best resolutions out of it:
      • 68/32 Ar/CO2 is put in GARFIELD for 70/30 gas
      • 89/11 Ar/CO2 is put in GARFIELD for 90/10 gas
      • +-6% CO2 can give 100~ns difference


Resolutions

  • Difference in gases - blue line is a model prediction:
Resolutions (in um) as a function of distance to the wire (in mm) for 70/30.
Resolutions (in um) as a function of distance to the wire (in mm) for 90/10.
  • 90/10 worse because shorter drift times.
  • Model contains:
    • Timing resolution (0.75 length of time sample)
    • accuracy
    • diffusion (Garfield)


  • Table with resolutions for straw 7 and different clock settings:
    • high: with hit removed from tracking
    • low: with hit included
Distance from wire [mm] Resolution (low) [um] Resolution (high [um]
125 MHz 200 MHz 125 MHz 200 MHz
0-1 388 394 404 396
1-2 346 292 346 205
2-3 209 191 222 210
3-4 142 135 166 165
4-5 118 96 164 151
5-6 85 88 148 164
6-7 67 70 165 174
7-8 65 63 158 169


  • The difference between high and low is largest for 1-3 mm driftdistances but overall the difference is not that big.
  • Gas mixture has a big impact
  • We might not have a big enough lever arm:
Drawing of the end plate of the small prototype.


GARFIELD - DATA

Below 70/30 gas mixture ch 7: left MC, right data

Resolutions as a function of drift distance (MC).
Resolutions as a function of drift distance (data).

To do

  • There is a full simulation of the chamber and results are on there way
  • We are testing 80/20 gas right now
  • We want to test the same gas mixture as FDC uses
  • We also want to try and add ethane
  • Try different timing algorithms
  • Find a way to extract the timing resolution directly
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