RoentDek DLD120, Manual

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MCP Delay Line (Version 6.2.90.5) Page 45 of 80
this value also to 0 and the program will automatically enter
the right number.
Parameter 107 Hit number to be analyzed. Usually the position is calculated
from the first hit in the TDC channels (default value: 1). If
you want to get position and time sum calculations with the
standard “TDC8 Standard.ccf” for a different hit number you
have enter the hit value here. Note, that it can happen that
the registered
channel numbers
do not necessarily correspond to
the real particle hit if reflections on the raw amplifier
signals produce “false” additional hits in a certain TDC
channel number, or if hits are “lost” due to low signal
height/high threshold settings.
Parameter 110 pTPCalX
Time to Position calibration factor for x (1/v
⊥
in mm/ns)
DLD40: 0.76, DLD80: 1.02, DLD120: 1.26
For Hexanode: … for u (1/v
⊥
in mm/ns), 1.3565 for HEX80.
Parameter 111 pTPCalY
Time to Position calibration factor for y (1/v
⊥
in mm/ns)
DLD40: 0.70, DLD80: 0.96, DLD120: 1.20
For Hexanode: … for u (1/v
⊥
in mm/ns), 1.4164 for HEX80.
These two parameters define the value of position to time
calibration, the effective signal propagation speed across the
delay-line. It depends on the size and geometry of the delay-
line used. The suggested values are only accurate within few
percent for a given delay-line. If a higher precision is needed
one needs to make a position calibration with a test mask in
front of the detector. If the detector shows an oval shape
please exchange the values for X and Y (only for DLD) and try
again to sort the data, possibly the physical dimensions of the
anode have been exchanged during mounting
.
Parameter 112 pTPCalW
Time to Position calibration factor for w (1/v
⊥
in mm/ns),
only for Hexanode: 1.4620 for HEX80
Parameter 120 pCOx Rotation Offset Center for PosX
Parameter 121 pCOy Rotation Offset Center for PosY
These parameters define the center point for an online detector
image rotation and also the center point in the X/Y plane for a
coordinate transformation into R/Phi representation. Note that
a R/Phi transformation will only give good results if the
position unit is mm (see parameter 100).
Parameter 122 pRotA Rotation Angle mathematical direction
Rotation angle (counter clock wise) for an online detector
image rotation
(value to be supplied in RAD or DEG depending on parameter 103)
Parameter 125 TDC channel number p of the MCP signal (default 0). If the MCP
timing signal is not used for the common start or common stop,
the x1,x2,y1,y2,z1 and z2 coordinate definitions are modified:
The raw values CmH1 are reduced by the raw value in the TDC
channel p (CpH1) of the MCP signal in this TDC channel number p
before further computation according to parameters 14 and 21
are eventually performed. p = 0 means: no substraction. The MCP
timing signals must then be connected to TDC channel p.
Parameter 135 pOPx Offset for PosX
Parameter 136 pOPy Offset for PosY
These two parameters are offset (additive) constants for
shifting the detector image in the X/Y plane. Note, that in
case of the Hexanode these values define the offsets for the
calculated x and y and not for the raw u and v values.