Coordinate raw_diffxy sum of TDC channel values 1&2 minus sum of 3&4
(uncalibrated)
Coordinate sumx,sumy,sumw,sumxyw same as raw_sum… but calibrated in ns and shifted (parameter
values)
example: sumx = x1 +x2 + pOSum
Coordinate diffxy same as raw_diffxy but calibrated in ns and shifted (parameter
values)
Coordinate PosX,PosY calibrated position coordinates after shift/rotation
(parameter values)
example: PosX = x1 - x2 + pOPx, and possibly rotated
(for Hexanode: Xuv + pOPx and Yvw + pOPy)
*
Coordinate r,phi calibrated position coordinates in R/Phi coordinate system
Coordinate Xuv,Yuv,Xuw,Yuw,Xvw,Yvw only for Hexanode: calibrated position coordinates retrieved
from the respective two layers
Coordinate dX,dY control coordinates: difference between Xuv/Xvw and
Yuv/Yvw
Coordinate reflection_in_MCP control coordinate: time between second and first hit in TDC
channel 8 (MCP) in ns.
Coordinate reflection_in_x1,reflection_in_x2 control coordinates: time between hit on one delay-line
contact and
Coordinate reflection_in_y1,reflection_in_y2 second hit on the other contact of the same delay-line, for all
layers and
Coordinate reflection_in_z1,reflection_in_z2 all ends (the latter two only for Hexanode
Coordinate Const1,Const2,Const3,Const4,Const5,Const6,Const7,Const8 internal coordinates for the
constants 1 to 8
CoordinateSet n_matrix_y,T1Ch01n,T1Ch02n,T1Ch03n,T1Ch04n,T1Ch05n,T1Ch06n,T1Ch07n,T1Ch08n
CoordinateSet n_matrix_x,Const1,Const2,Const3,Const4,Const5,Const6,Const7,Const8
The keyword "CoordinateSet" combines several coordinates in a group. In the example above the coordinates T1Ch01n to
T1Ch08n are combined in a group with the name "n_matrix_y". In the histogram definitions these group names can be used
as if they were normal coordinates. Thus the command
define2 0.,9.,1.,n_matrix_x,channel number,0.,8.,1.,n_matrix_y,counts,none,always,hit statistics
results in a 2D-histogram which is filled at the following 8 bin positions:
x=Const1 / y=T1Ch01n, x=Const2 / y=T1Ch02n, x=Const3 / y=T1Ch03n, x=Const4 / y=T1Ch04n
x=Const5 / y=T1Ch05n, x=Const6 / y=T1Ch06n, x=Const7 / y=T1Ch07n, x=Const8 / y=T1Ch08n
Spectra and condition definition commands
The final purpose of the data acquisition is to display and analyze the acquired data. For this purpose it is possible to define
spectra for displaying all defined coordinates. A spectrum is a histogram with a fixed bin width either with a one- or two
dimensional array of “bins”. For a one-dimensional spectrum (for example a time spectrum) this array is a row along the
ordinate (X-axis) of a graph, the bins correspond to the values of the corresponding coordinate. When data is acquired or read
from a list-mode file, the value of the coordinate for each event will be attributed to the closest bin’s value and the histogram
content in this bin will be incremented by one unit (along the Y-axis of the graph). For example such a histogram (spectrum)
could show the distribution of time of flight values for a number of acquired events.
Likewise it is possible to display two-dimensional spectra, i.e. the coincident occurrence of values in two coordinates within the
corresponding bin widths (for example the 2d position distribution of detected particles). To visualize such a histogram the two
coordinates span a plane (X/Y), the value in each bin (Z) is displayed as gray or color scale, also contour lines or scatter plots
can be used for the display. The range of the displayed spectra in X, Y (and Z), the bin size and the “unit” of incrementing can
be defined for optimal visualization and manipulation.
To analyze higher dimensional coordinate correlations it is possible to “gate” the sorting process into a histogram (spectrum)
by defining a condition for this spectrum. Such a condition can be a “window” (or “region of interest”) on the occurrence of a
certain range of values in a third coordinate for the events. For example: if one needs to visualize the (2d) position spectra of
particles as function of their time-of-flight (TOF) one can define several conditions (gates) on the TOF coordinate (e.g. time
sum peaks) and several 2d position spectra with the different conditions. It is possible to couple different conditions (e.g. by
an “AND”) to allow the analysis of even higher dimensional coordinate correlations.
*
In order to get an optimal image from a Hexanode it is important to calibrate the layers accurately using add-on software
MCP Delay Line Detector Manual (11.0.1304.1) Page 65 of 83
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