Contents

List of Tables

1.  Additions to the espace manual for the FPP

1.1  FPP options that can be set for ESPACE

In ESPACE one can set options in the kumac with the command file/option as a way to tell ESPACE you would like to do when scanning the data. An example line in a kumac is file/option 'ana_fpp_front on'. Below is a listing of possible options for FPP and the settings for the

option

settings description

ana_fpp_front

on/off Tells espace to do tracking in the front FPP planes. (default off).

ana_fpp_rear

on/off Tells espace to do tracking in the rear FPP If both ana_fpp_front and ana_fpp_rear are off then ESPACE doesn't do any of FPP part of code. (default off)

evdsp_fpp

on/off Write info on fpp track to file fort.30 which can be used in a track display program. (default off)

calibration

on/off Tells espace that you want to do either a calibration of the time offsets or gates on the demux spectra. Calibration of the demux gates is done when the option pulser_fpp is on. Otherwise calibration of the time offsets is done. (Default off)

icalib

n Used when calibration is on. For calibration of demux gates. n is the number of the wire that was pulsed during the run. For calibration of the time offsets n=0 means calibrate the crude time offsetsand n=2 means calibrate the reference time offsets. (Default 0)

alignment

on/off Tells ESPACE that you want to do a determination of the alignment parameters in Ed Brash's alignment method. (Default off)

ialign

n Used when alignment is on. n is a integer. n=0 means align the front chambers. n=1 means align the rear chambers. (Default 0)

debug_fpp

on/off Tells ESPACE that you want to look FPP information on an event-by-event basis. Info written to file fort.25 . (Default off)

pulser_fpp

on/off Tells ESPACE that data was taken with pulser so skip the tracking part of FPP code. (Default off)

init_param

No setting Tells ESPACE to read in parameter files fpp_toffset_crude.calib,fpp_toffset_ref.calib,fpp_demux_gates.dat, fpp_alignment_matrix_front.dat, fpp_alignment_matrix_rear.dat which are necessary for the FPP part of ESPACE.

1.2  Files needed for ESPACE to do FPP analysis

In addition to the standard database and header files that ESPACE needs, when running ESPACE one needs certain files in the directory where you are running ESPACE. Below is a list of the files

fpp_demux_cuts.dat

Contains the gates for the demux spectra. File format has 9 numbers per line (gates per wiregroup of plane) The file allocates 35 wiregroups per plane (so some planes have lots of zeroes) and the cuts are listed in physical order of planes as given in Table~1 .

fpp_toffset_crude.calib

The first order time offset to the drift time spectra. The file format is one line for each time offset of a wiregroup and 40 lines are given for each plane. The time offsets are listed in physical order of planes as given in Table~1.

fpp_toffset_ref.calib

Second order time offset to the drift time spectra. File has same format as fpp_toffset_crude.calib.

fpp_drift_dist_fits.dat

Coefficents for a fifth order polynomial which converts drift time to drift distance. File format is one line per plane with planes listed in their physical order.

fpp_alignment_matrix_front.dat

Coefficients for linear equations which correct x , y , f , q for front chambers.

fpp_alignment_matrix_rear.dat

Coefficients for linear equations which correct x , y , f , q for rear chambers.

1.3  Description of variables in FPP part of ESPACE

All variables for the FPP in ESPACE start with the name spec_h and then there are two types of variables: one type is calculated for each plane in the FPP and the other is calculated for the whole FPP package. Below are the variables calculated for the whole FPP package and they are referenced for histogrammimg as spec_h.fpp.var with a listing of the possible var to follow

ntothits

Total number of hits in front and rear FPP chambers

x_fa

X-position at the U1 plane of VDC calculated from front FPP track (cm)

x_diff_f

Difference between x-position at the U1 plane of VDC calculated by VDC minus front FPP (cm)

y_fa

Y-position at the U1 plane of VDC calculated from front FPP track (cm)

y_diff_f

Difference between y-position at the U1 plane of VDC calculated by VDC minus front FPP (cm)

th_f

Angle in the y-z plane ( atan(dy/dz) ) for front FPP track (deg)

th_diff_f

Difference between angle in the y-z plane (atan(dy/dz)) for VDC and front FPP track (deg)

ph_f

Angle in the x-z plane ( atan(dx/dz) ) for front FPP track (deg)

ph_diff_f

Difference between angle in the x-z plane ( atan(dx/dz) ) for VDC minus front FPP track (deg)

x_r

X-position at z=350cm from the U1 plane of VDC calculated from rear FPP track (cm)

x_fb

X-position at z=350cm from the U1 plane of VDC calculated from front FPP track (cm)

x_diff_r

Difference between x-position at z=350cm from the U1 plane of VDC calculated by rear minus front FPP (cm)

y_r

Y-position at z=350cm from the U1 plane of VDC calculated from rear FPP track (cm)

y_fb

Y-position at z=350cm from the U1 plane of VDC calculated from front FPP track (cm)

y_diff_r

Difference between y-position at z=350cm from the U1 plane of VDC calculated by rear minus front FPP (cm)

th_r

Angle in the y-z plane ( atan(dy/dz) ) for rear FPP track (deg)

th_diff_r

Difference between angle in the y-z plane ( atan(dy/dz) ) for rear minus front FPP track (deg)

ph_r

Angle in the x-z plane ( atan(dx/dz) ) for front FPP track (deg)

ph_diff_r

Difference between  angle in the x-z plane ( atan(dx/dz) ) for rear  minus front FPP track (deg)

th_sc

Angle between the z-axis and the projection of the scattered track on the x-z plane. (deg)

ph_sc

Angle between the z-axis and the projection of the scattered track on the z-y plane. (deg)

th_az

The polar angle q. (deg)

ph_az

The polar angle f. Zero f is along the positive y-axis and f increases as it moves towards positive x-axis. (deg)

zclose

The distance along the z-axis of closest approach between the front FPP track and the read FPP track. (cm)

sclose

The distance between the front and read tracks at zclose. (cm)

ntrackfu

Number of front U tracks per event. Right now no multiple tracking in the code so only values are 0 or 1.

ntrackfv

Number of front V tracks per event

ntrackru

Number of rear U tracks per event

ntrackrv

Number of rear V tracks per event

conetest

Values are 1 if cone test was passed and -1 if conetest was failed.

The variables for each plane are referenced as spec_h.plane.var . ESPACE has both scaler and array variables. The readout of the FPP chambers is multiplexed in groups of 8 wires called wiregroups. It is natural to make arrays of variables for each plane so that one can look at the individual wiregroup. For the front chambers the V planes have 20 wiregroups and the U planes have 22 wiregroups. For the rear chamber 3 the U and V planes have 30 wiregroups and the X planes have 31 wiregroups. For the rear chamber 4 the U and V planes have 34 wiregroups. In ESPACE to histogram an individual member of an array then it is referenced as spec_h.plane.var [wg;wg] . If the array variable is referenced without a [wg;wg] then all wiregroups within the plane are included in the histogram. FPP variables are also divided into those which are calculated for all raw hits and those that are calculated for GOOD hits. A list of the variable names for raw hits follows

nhits

Number of hits per plane (scaler).

wiregroup

Wiregroup number for all hits (array)

straw_raw

Straw number for all hits (array)

lete_raw

Leading edge - trailing edge for all hits (ns) (array)

ltdc

Leading edge time for all hits (0.5ns) (array)

straw

Straw number for GOOD hits (array)

dist

Drift distance for GOOD hits (array)

ltdc_cor

Leading edge time (corrected for time offset) for GOOD hits (ns) (array)

letediff

Leading edge - trailing edge for GOOD hits (ns) (array)

resid

Difference between measured position and a position calculated by the track (cm) (array)

strwgood

Straw number for straws hit by the fitted track and also had detected a hit in the straw. Used for straw by straw efficiency. (array)

strwbad

Straw number for straws hit by the fitted track but did not have a hit in the straw in that plane. Used for straw by straw efficiency. (array)

nghits

Number of GOOD hits per planes (array)