HCal MIP Calibration

MIP calibration constants have units [ADUp/Mip], where ADUp are ADC unit in physics mode and a Mip is defined by the most probable value of the spectrum recorded from the passage of a minimum ionizing particle at normal incidence. The constants are made available in the database in folder

/cd_calice/Hcal/mip_constants 

These calibration parameters are temperature dependent. The slopes dMip/dT for each channel are stored in the database folder

/cd_calice/Hcal/mip_slopes 

Every entry gets tagged to allow permanent reference. Users are encouraged to use tags rather than the HEAD, i.e. make sure they know which assumptions are valid on the constants they use.

Tag description: mip_constants

Tag

Time / HV Period

Description

ahc_mip_constants_001

2006 - 2009

Mip values at 0 degress centigrade extracted from linear fit to CERN 2007 measurements. Mip coefficients for linear fit extracted by Andrea.

ahc_mip_constants_002

C06

same as ahc_mip_constants_001

C07

mip values extracted by Andrea from runs 330254, 330255, 330256, 330257, 330258.

F08-1

Values from period F08-2 (valid for different voltage settings). Only commissioning data in this period.

F08-2

mip values extracted by Andrea from runs 500105, 500106, 500107

F08-3

mip values extracted by Andrea from runs 500278, 500279, 500285, 500286, 500293, 500300, 500305, 500306. Only one muon per event is used for calibration, additional muons are rejected.

F08-4

mip values extracted by Andrea from runs 530741, 530742, 530744, 530745, 530746, 530747, 530762, 530763, 530764, 530765, 530766, 530767, 530768, 530770. Value for hot cell (signal too high in online monitor; module 4, chip 2, channel 15) removed manually.

ahc_mip_constants_003

C06

same as ahc_mip_constants_001

C07

average of mip values extracted by Boris for runs 330254, 330255, 330256, 330257, 330258.

F08-1

Empty. Only commissioning data in this period.

F08-2

same as ahc_mip_constants_002

F08-3

same as ahc_mip_constants_002

F08-4

same as ahc_mip_constants_002

ahc_mip_constants_004

2006 - 2009

Copy of ahc_mip_constants_001, added default mip value to collection parameters (default = 100000)

ahc_mip_constants_005

2006 - 2009

Copy of ahc_mip_constants_002, added default mip value to collection parameters (default = 100000)

ahc_mip_constants_006

2006 - 2009

Copy of ahc_mip_constants_003, added default mip value to collection parameters (default = 100000)

ahc_mip_constants_007

C06

same as ahc_mip_constants_001

C07

mip values extracted by Boris with likelihood fit to merged histograms from runs 330254, 330255, 330256, 330257, 330258.

F08-1

-empty-

F08-2

mip values extracted by Boris with likelihood fit to merged histograms from runs 500105, 500106, 500107 (WARNING: low statisitcs, large errors!)

F08-3

mip values extracted by Boris with likelihood fit to merged histograms from runs 500278, 500279, 500285, 500286, 500293, 500300, 500305, 500306. Only one muon per event is used for calibration, additional muons are rejected.

F08-4

mip values extracted by Boris with likelihood fit to merged histograms from runs 530741, 530742, 530744, 530745, 530746, 530747, 530762, 530763, 530764, 530765, 530766, 530767, 530768, 530770

ahc_mip_constants_008

C06

same as ahc_mip_constants_001

C07

same as ahc_mip_constants_007

F08-1

Values from period F08-3 (valid for different voltage settings). Only commissioning data in this period.

F08-2

same as ahc_mip_constants_007

F08-3

same as ahc_mip_constants_007

F08-4

same as ahc_mip_constants_007

C10

Values from period C07 (same voltage settings)

ahc_mip_constants_009

C06

same as ahc_mip_constants_001

C07

same as ahc_mip_constants_007

F08-1

same as ahc_mip_constants_008

F08-2

same as ahc_mip_constants_007

F08-3

same as ahc_mip_constants_007

F08-4

same as ahc_mip_constants_007

F09

same as ahc_mip_constants_008

C10

mip values extracted by Andrea, Angela ...

C11

mip values from C07

ahc_mip_constants_010

C06

same as ahc_mip_constants_001

C07

same as ahc_mip_constants_007

F08-1

same as ahc_mip_constants_008

F08-2

same as ahc_mip_constants_007

F08-3

same as ahc_mip_constants_007

F08-4

same as ahc_mip_constants_007

F09

same as ahc_mip_constants_008

C10

same as ahc_mip_constants_009

C11

mip values updated with the testbeam muon runs by CERN group

ahc_mip_constants_011

C06

same as ahc_mip_constants_001

C07

mip constants value same as ahc_mip_constants_007, and reference temperature correction with median filter by Sergey, and AhcMedianFilterTempProvider will be used for the data to provide the corrected temperature at the same time

F08-1

same as ahc_mip_constants_008

F08-2

same as ahc_mip_constants_007

F08-3

same as ahc_mip_constants_007

F08-4

same as ahc_mip_constants_007

F09

same as ahc_mip_constants_008

C10

same as ahc_mip_constants_009

C11

mip values updated with the testbeam muon runs by CERN group

Tag description: mip_slopes

Tag

Time / HV Period

Description

ahc_mip_slopes_001

2006 - 2009

Absolute slopes extracted from linear fit to CERN 2007 measurements. mip coefficients for linear fit extracted by Andrea.

ahc_mip_slopes_002

C06

same as ahc_mip_slopes_001

C07

For each channel: slope = -3.8%/K (average relative dependence) * mip constant (from ahc_mip_constants_002)

F08-1

F08-2

F08-3

F08-4

ahc_mip_slopes_003

2006 - 2009

Copy of ahc_mip_slopes_001, added default slope to collection parameters (default = 0)

ahc_mip_slopes_004

2006 - 2009

Copy of ahc_mip_slopes_002, added default slope to collection parameters (default = 0)

ahc_mip_slopes_005

C06

same as ahc_mip_slopes_001

C07

For each channel: slope = -3.7%/K (average relative dependence) * mip constant (from ahc_mip_constants_007)

F08-1

- empty -

F08-2

For each channel: slope = -2.4%/K (average relative dependence) * mip constant (from ahc_mip_constants_007)

F08-3

For each channel: slope = -2.4%/K (average relative dependence) * mip constant (from ahc_mip_constants_007)

F08-4

For each channel: slope = -2.4%/K (average relative dependence) * mip constant (from ahc_mip_constants_007)

ahc_mip_slopes_006

C06

same as ahc_mip_slopes_001

C07

For each channel: slope = -3.7%/K (average relative dependence) * mip constant (from ahc_mip_constants_008)

F08-1

Values from period F08-3 (valid for different voltage settings). Only commissioning data in this period.

F08-2

For each channel: slope = -3.1%/K (average relative dependence) * mip constant (from ahc_mip_constants_008)

F08-3

For each channel: slope = -3.1%/K (average relative dependence) * mip constant (from ahc_mip_constants_008)

F08-4

For each channel: slope = -2.3%/K (average relative dependence) * mip constant (from ahc_mip_constants_008)

C10

Values from period C07 (same voltage settings)

ahc_mip_slopes_007

C06

same as ahc_mip_slopes_001

C07

same as ahc_mip_slopes_006

F08-1

same as ahc_mip_slopes_006

F08-2

same as ahc_mip_slopes_006

F08-3

same as ahc_mip_slopes_006

F08-4

For each channel: slope = -3.4%/K (average relative dependence) * mip constant (from ahc_mip_constants_009)

F09

For each channel: slope = -3.4%/K (average relative dependence) * mip constant (from ahc_mip_constants_009)

C10

For each channel: slope = -3.7%/K (average relative dependence) * mip constant (from ahc_mip_constants_009)

C11

value from C07

ahc_mip_slopes_008

C06

same as ahc_mip_slopes_001

C07

same as ahc_mip_slopes_006

F08-1

same as ahc_mip_slopes_006

F08-2

same as ahc_mip_slopes_006

F08-3

same as ahc_mip_slopes_006

F08-4

same as ahc_mip_slopes_007

F09

same as ahc_mip_slopes_007

C10

same as ahc_mip_slopes_007

C11

TODO: get the information from the provider?

outdated MIP calibration folders

The tags of some outdated MIP calibration folders are still listed here.

How to obtain a MIP calibration

Individual MIP calibration constants for each SiPM, can be obtained using muon runs taken at the test beam area. Two Marlin processors and a fitting procedure are needed to obtain the MIP values.

A summary of the muon runs collected in CERN 2007, FNAL 2008 and FNAL 2009 can be found here HCAL MuonRuns.

Reconstruction of the muon track

TrackFinder is a Marlin processor which identifies mip-like tracks using muon runs. It finds all muon tracks in the event if a tower of at least N entries is found. N is a steering parameter. The discrimination of signal hits to noise hits uses a 0.5 MIP cut. Therefore, initial MIP values like initialMips.txt have to be provided.

This processor returns a collection of calorimeter tracks. Each calorimeter track is build by hits where information on "module, chip, channel" and "amplitude" in units of [ADC] is stored.

A steering example for processing 2007 and 2008 muon data, you can find here muonTrack2007.txt, muonTrack2008.txt.

Creation of Histograms

Histograms are created with the CellAnalysisProcessor, it takes as input the calorimeter track collection defined by the TrackFinderProcessor. The binning and the intervals required to define the histograms are steering parameters. A root file containing 7608 histograms is produced. A steering example can be found here cellAnalysis.txt

Fitting Procedure

The last step involves the fitting of the histograms. A convolution of Gaussian and Landau distribution is used to fit the MIP spectra.

HCAL MIP (last edited 2013-09-13 08:32:13 by ShaojunLu)