The instructions of the drift section fall in 4 categories: - setting various parameters - calibration - display of drift behaviour - service instructions This is probably the most intensively used section of Garfield. Before loops and procedure calls became available, many requests for instructions that are variations on existing instructions were made. This has lead to a fair amount of duplication among the instructions. ------------------------------------------------------------------------ Setting parameters: ------------------------------------------------------------------------ AREA Sets the size and view of the drift area GRID Grid density for tables and contour plots INTEGRATION-PARAMETERS Accuracy of diffusion, Townsend integration LINES Number of drift lines used by x(t) etc. OPTIONS Debugging options SELECT Selection of sense wires TRACK Sets the particle trajectory TRAP Change-over point of integration algorithm ------------------------------------------------------------------------ Calibration: ------------------------------------------------------------------------ ARRIVAL-TIME-DISTRIBUTION x(t) Relations, detailed calculation MINIMISE Search for the minimum of a function TABLE Produces a drift time table TIMING Arrival time distributions for 2D areas XT-PLOT x(t) Relations, simple variant ------------------------------------------------------------------------ Display drift behaviour: ------------------------------------------------------------------------ CLUSTERING-HISTOGRAMS Makes histograms of the cluster statistics DRIFT Plots drift lines and isochrones GRAPHICS-INPUT Graphics menu driven drift line plotting LORENTZ Prints the Lorentz angle at a given point PLOT Plots drift related quantities SINGLE Graphs for a single drift line SPEED Prints the drift speed at a given point TIME Timing of drift line calculation ------------------------------------------------------------------------ Service instructions: ------------------------------------------------------------------------ PREPARE-TRACK Prepares a track of interpolation WRITE-ISOCHRONES Writes the set of isochrones to a file WRITE-TRACK Writes a prepared track to a file Note: There are procedures that perform drift related tasks: DRIFT_ELECTRON, DRIFT_MC_ELECTRON, DRIFT_ELECTRON_3, DRIFT_ION, DRIFT_MC_ION, DRIFT_ION_3, GET_DRIFT_LINE, PLOT_DRIFT_LINE, NEW_TRACK, GET_CLUSTER, PLOT_TRACK, PLOT_DRIFT_AREA and others. The FIT_GAUSSIAN procedure can be of use when studying the output of the ARRIVAL instruction.
Changes the area in which electrons and ions are allowed to drift. This is also the part of the chamber that is plotted. Formats: See &FIELD -> AREA
Computes the arrival time distribution of the n'th electron from a series of tracks, for each selected wire in the AREA currently set. A by-product of this calculation is the x(t) relation and an estimate of the arrival time spread. See also XT-PLOT for a comparison with this related command. This command overwrites the geometrical track information from the TRACK command, but respects the kind of track. Since the default track type (a fixed number of deposits at regular intervals) is not meaningful in the present context, it is important to set the track type before issuing the ARRIVAL comand. The PROGRESS-PRINT global option enables you to follow the progress of the calculations - which tend to be lengthy. Format: ARRIVAL-TIME-DISTRIBUTION ... [ELECTRON {electron | LAST | ONE-BUT-LAST | ... }] ... [THRESHOLD threshold] ... [NOAUTOSCALE-TIME-WINDOW | AUTOSCALE-TIME-WINDOW] ... [TIME-WINDOW tmin tmax ] ... [X-RANGE xmin xmax] [X-STEP-SIZE x_step] ... [Y-RANGE ymin ymax] [LINES lines] [ANGLE phi] ... [DIFFUSION | NODIFFUSION] ... [ATTACHMENT | NOATTACHMENT] ... [DATASET dsname [member]] [REMARK remark] ... [BINS bins] ... [ITERATIONS loops] ... [POLYNOMIAL-ORDER order] ... [NOKEEP-HISTOGRAMS | KEEP-HISTOGRAMS] ... [NOKEEP-RESULTS | KEEP-RESULTS] ... [NOPLOT-EACH-X-OVERALL | PLOT-EACH-X-OVERALL] ... [NOPLOT-EACH-X-SELECTED-ELECTRON | ... PLOT-EACH-X-SELECTED-ELECTRON] ... [NOPRINT-EACH-X-OVERALL | PRINT-EACH-X-OVERALL] ... [NOPRINT-EACH-X-SELECTED-ELECTRON | ... PRINT-EACH-X-SELECTED-ELECTRON] ... [PLOT-OVERVIEW | NOPLOT-OVERVIEW] If you don't manage to fit all this on a single line, remember that an instruction can be split over several lines by putting an ellipsis at the end of each line but the last. Example: TRACK EXPONENTIAL ARRIVAL ELECTRON 5 LAST DATASET "arrival/electron.5" THRESH 0.8 First, the track type is set to EXPONENTIAL, i.e. the mean number of clusters per cm and the cluster size distribution from the gas section are used. One could also ask for HEED. Then, the arrival time distribution of the 5th and of the last electron are computed. A file is written that contains the the time by which 80 % of these electrons have reached the wire.
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Makes a set of histograms that show some aspects of the cluster statistics: - distance between electrons and track - number of clusters on the track - number of electrons on the track - energy in each cluster (if available) - total energy loss over the track (if available) These histograms are of use mainly if Heed is used to generate tracks. Keep the following in mind in this respect: - Heed, internally, doesn't have a concept of clusters. Most electrons that are deposited in the gas stem from "virtual gammas" which ionise a gas molecule by liberating electrons that may (delta electrons) or may not have enough energy to ionise further gas molecules. When you use the NODELTA-ELECTRONS option of TRACK, then all electrons that stem from a single virtual photon are placed at the location where the virtual photon was absorbed, thus creating a cluster. Such a cluster will usually be located very close to the track. With this option, the cluster size distribution is of interest, but the distance between track and electrons is meaningless. When you use the DELTA-ELECTRON option of TRACK, the electrons generated by Heed are each considered a cluster, of size 1. The electrons will usually be located further from the track than the virtual photons. With this option, the cluster size distribution is of no interest, while the distribution between track and electrons reflects the range of delta electrons. - When using the MULTIPLE-SCATTERING option of TRACK, which is not default, then the distance between electrons and track is measured with respect to the average trajectory, i.e. the trajectory of the particle if there were no multiple scattering. Format: CLUSTERING-HISTOGRAMS ... [ITERATIONS iter] ... [BINS bins] ... [CLUSTER-SIZE-BINS bins] ... [CLUSTER-SIZE-RANGE {AUTOMATIC | min max}] ... [CLUSTER-COUNT-BINS bins] ... [CLUSTER-COUNT-RANGE {AUTOMATIC | min max}] ... [CLUSTER-ENERGY-BINS bins] ... [CLUSTER-ENERGY-RANGE {AUTOMATIC | min max}] ... [DELTA-RANGE-BINS bins] ... [DELTA-RANGE-RANGE {AUTOMATIC | min max}] ... [TRACK-RANGE-BINS bins] ... [TRACK-RANGE-RANGE {AUTOMATIC | min max}] ... [ENERGY-LOSS-BINS bins] ... [ENERGY-LOSS-RANGE {AUTOMATIC | min max}] ... [NOKEEP-HISTOGRAMS | KEEP-HISTOGRAMS] ... [PLOT-HISTOGRAMS | NOPLOT-HISTOGRAMS]
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This instruction makes plots of electron and ion drift lines and can also plot isochrones. The main choice is between the 4 possible starting points: the edges of the AREA, the surface of the SELECTed wires, the TRACK and the ZEROs of the electrostatic field. Each has a set of sub-options that should follow the EDGE, WIRE, TRACK or ZERO keyword. The other options should be placed at the end of the line. Format: DRIFT {EDGE [LEFT | NOTLEFT] ... [RIGHT | NOTRIGHT] ... [UP | NOTUP] ... [DOWN | NOTDOWN] ... [LINES lines] | ... TRACK [NOTIME-GRAPH | TIME-GRAPH] ... [NOVELOCITY-GRAPH | VELOCITY-GRAPH] ... [NODIFFUSION-GRAPH | DIFFUSION|GRAPH] ... [NOAVALANCHE-GRAPH | AVALANCHE-GRAPH] ... [NOFUNCTION-GRAPH | FUNCTION-GRAPH function] ... [MARKER | SOLID] | ... WIRE [LINES lines] | ... ZEROS } ... [RUNGE-KUTTA-DRIFT | MONTE-CARLO-DRIFT] ... [NOISOCHRONES | ISOCHRONESdelta_t] ... [LINE-PLOT | NOLINE-PLOT] ... [NOLINE-PRINT | LINE-PRINT] ... [ELECTRON | ION] ... [NEGATIVE | POSITIVE] If you don't manage to fit all this on one line, remember you are allowed to abbreviate. A line that ends on an ellipsis continues on the next line. Examples: DRIFT WIRE LINES=25 ISOCHRONES 0.1 NOL-PL DRIFT TRACK FUNCTION-GRAPH TIME+5*DIFFUSION NOL-PL L-PR DRIFT ZEROS (The first example will plot only a set of isochrones computed using 25 drift lines from each of the selected wires. The second example prints a table of drift times etc. and plots the drift time plus five times the diffusion. The last example shows the acceptance boundaries.)
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Enters a graphics menu driven mini drift section. The edges of the AREA and the TRACK can very easily be changed by simply pointing to them. Typical calculations include a single drift line from a point indicated on the screen, drift lines from the TRACK and drift lines from a wire (and its periodic repetitions) selected on the screen. You have some control over the graphics input mode with the options listed below. Format: GRAPHICS-INPUT [CHOICE-PET chpet] [LOCATOR-PET locpet1 locpet2] ... [PICK-PET pickpet] [VALUATOR-PET valpet] ... [CHOICE-DEVICE chdev] [LOCATOR-DEVICE locdev] ... [PICK-DEVICE pickdev] [VALUATOR-DEVICE valdev] ... [WORK-STATION wkid] Example: GRA LOC-PET 1 4 Chooses rubber band for the second point.
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Chooses the x (or r) and y (or phi) density of the grid inside the AREA from which the TABLE instruction will calculate drift lines. The second arguments may be omitted in which case the first value will be used for both the x (or r) and the y (or phi) spacing. Format: GRID number_of_steps_in_x [number_of_steps_in_y] Example: GRID 10 20
Enables one to change the following: - the drift line integration accuracy; - the step size for Monte Carlo drifting; - the distance from a wire where a electron or ion is considered to be caught by the wire; - the distance at which the integration algorithm for transverse + longitudinal diffusion projects the cloud radially onto the wire; - the method by which the cloud is projected into the wire; - the maximum stack depth and the relative accuracy of the integration of the diffusion coefficient, the Townsend coefficient and the attachment coefficient; - conditions under which isochrone segments are joined; - appearance of isochrones. These parameters are used both in this section and in the signal section. Format: INTEGRATION-PARAMETERS ... [INTEGRATION-ACCURACY accuracy] ... [ MONTE-CARLO-TIME-INTERVAL tstep | ... MONTE-CARLO-DISTANCE-INTERVAL dstep | ... MONTE-CARLO-COLLISIONS nstep] ... [ CHECK-ATTRACTING-WIRES | ... CHECK-ALL-WIRES] ... [ REJECT-KINKS | ... NOREJECT-KINKS] ... [TRAP-RADIUS ntrap] ... [CLOUD-PROJECTION-DISTANCE ncloud] ... [CLOUD-PROJECTION-METHOD method] ... [DIFFUSION-ACCURACY eps_diff] ... [TOWNSEND-ACCURACY eps_Town] ... [ATTACHMENT-ACCURACY eps_att] ... [DIFFUSION-STACK-DEPTH stack_diff] ... [TOWNSEND-STACK-DEPTH stack_Town] ... [ATTACHMENT-STACK-DEPTH stack_att] ... [ DRAW-ISOCHRONES | ... MARK-ISOCHRONES] ... [ SORT-ISOCHRONES | ... NOSORT-ISOCHRONES] ... [ ISOCHRONE-CONNECTION-THRESHOLD iso_thr | ... NOISOCHRONE-CONNECTION-THRESHOLD] ... [ISOCHRONE-ASPECT-RATIO-SWITCH iso_aspect] ... [ISOCHRONE-LOOP-THRESHOLD iso_loop] ... [ CHECK-ISOCHRONE-CROSSINGS | ... NOCHECK-ISOCHRONE-CROSSINGS] Example: INT DIFF-ST 5, DIFF-ACC 1.0E-3 Will limit the number of subdivisions to 32 per drift line step (the default is usually 2**20) and asks for a relative precision per step of one permille.
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Sets the default number of drift lines for a couple of commands such as track preparation. The parameter also governs in part the accuracy of the x(t) calculation in sets the number of drift lines used for the initial crude search for the optimal point in y for each x. Please note that LINES has no effect anymore on the DRIFT command. For DRIFT TRACK, use the TRACK command itself to set the number of lines. For DRIFT WIRE and DRIFT EDGE, use the LINES option of the DRIFT command. Format: LINES lines Example: LINES 50
Prints the Lorentz-angle, i.e. the angle between the drift vector and the electric field, at the point (x,y,z). Format: LORENTZ-ANGLE x y z Example: LORENTZ 0.5 0.5 1
Searches for the minimum of e.g. the drift time over a curve. Format: MINIMISE f_min [SELECTION-FUNCTION f_select] ... ON f_curve RANGE t_min t_max N n ... [ELECTRON | ION] [NEGATIVE | POSITIVE] ... [FUNCTION-PRECISION eps_f] ... [POSITIONAL-RESOLUTION eps_pos] ... [ITERATE-LIMIT itermax] ... [PRINT | NOPRINT] ... [DATASET dataset [member] [REMARK remark]] Example: MINIMISE TIME ON '5*COS(T), 5*SIN(T)' RANGE {PI/4,3*PI/4} This instruction asks for a minimisation of the drift time over an arc with radius 5 and in the angular range pi/4 to 3 pi/4. Note that quotes are used to specify the curve: a comma has to be placed between the two coordinates, but since the comma is a separator and since ON expects only one element, the expression is placed in quotes. RANGE on the other hand expects two elements and quotes should therefore not be used !
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Determines whether the drift lines produced by other commands than the DRIFT instruction are plotted or printed. Commands affected by these options include ARRIVAL, PREPARE-TRACK etc. Format: OPTIONS [DRIFT-PRINT | NODRIFT-PRINT] ... [DRIFT-PLOT | NO-DRIFT-PLOT] ... [KEY | NOKEY] ... [CONTOUR-ALL-MEDIA | CONTOUR-DRIFT-MEDIUM] Example: OPT DR-PL NODR-PR
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This instruction plots the quantities related to drifting of electrons and ions in a variety of ways, such as contours, a surface plot, a graph, a histogram. Similar instructions exist in the field and signal sections. Please note that the parameter V has a different meaning in the field section (where stands for the potential) than in the drift section (where it stands for the electron velocity). CPU time can be saved if several plots are combined in a single command. Format: PLOT-FIELD [CONTOUR [f1] [RANGE {cmin cmax | AUTOMATIC}] ... [N n] ... [LABELS | NOLABELS]] ... [GRAPH [f2] [ON f_curve] ... [N n]] ... [SCALE min max] ... [NOPRINT | PRINT] ... [HISTOGRAM [f3] [RANGE {hmin hmax | AUTOMATIC}] ... [BINS nbin]] ... [SURFACE [f4] [ANGLES phi theta]] ... [VECTOR [f5 f6]] ... [ELECTRON | ION] ... [POSITIVE | NEGATIVE] If you don't manage to fit all this on a single line, remember that lines that end on an ellipsis are continued on the next. Examples: PLOT HIST DIFFUSION VECTOR VDX, VDY SURF CONT PLOT CONTOUR TIME RANGE 0.1 0.3 (The first example makes most of the plots using default functions and ranges - useful as a first call. The second example makes a more detailed contour plot.)
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Calculates and stores the relevant drift line information for regularly spaced points on the track. This data can optionally be used in the actual signal simulation so as to save CPU time. The difference in speed can be dramatic if the simulation is repeated many times. The loss in accuracy is usually negligible. The track thus prepared, can be saved in a dataset from where it can be retrieved in subsequent runs. Format: PREPARE-TRACK ... [ATTACHMENT-COEFFICIENT | NOATTACHMENT-COEFFICIENT] ... [DIFFUSION-COEFFICIENT | NODIFFUSION-COEFFICIENT] ... [TOWNSEND-COEFFICIENT | NOTOWNSEND-COEFFICIENT] ... [LINES n] Example: PREP-TR (Accept all defaults, usually adequate.)
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Selects and groups the sense-wires. The grouping is of no importance in this section. The selection determines which wires are used by DRIFT WIRE and XT-PLOT. The argument string consists of wire-codes and/or wire-numbers. Format: SELECT wire_selection Example: SEL (1 S) 2 F (Put wire 1 together with all S wires in one group, make wire 2 a group of its own and do the same for each of the F wires.)
An instruction that will print and plot details about a single drift line from (x,y). The information can be presented as a table of the position, the integrated drift time and a user specified function, but also as a graph of one function against another. Format: SINGLE FROM x y ... [PLOT f1 VS f2 | NOPLOT] ... [PRINT f3 | NOPRINT] ... [NEGATIVE | POSITIVE] ... [ELECTRON | ION] Examples: SINGLE FROM 0.5 0.3 PLOT DIFFUSION VS PATH SINGLE FROM 0.1 0.2 PRINT VDX
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A debugging instruction that will evaluate the drift speed at a given point (x,y,z). The POSITIVE or NEGATIVE keyword should, if used, be last on the line. Format: SPEED x y z [ELECTRON|ION] [NEGATIVE|POSITIVE] Example: SPEED 0.5 1.5 0
Prints a table of drift times for electrons or ions starting from GRID by GRID regularly spaced points inside the AREA. This command is highly CPU time consuming. The POSITIVE or NEGATIVE keyword should, if used, be last on the line. Format: TABLE [TABLE | NOTABLE] ... [NOCONTOUR | CONTOUR] ... [ELECTRON | ION] ... [NEGATIVE | POSITIVE] This command must be entered on a single line ! Example: TABLE (Only produce the table, no contours.)
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Times n drift line calculations [default: 10]. Format: TIME [n] Example: TIME 5
Computes the arrival time distribution of the n'th electron over a given area. Unlike the ARRIVAL instruction, TIMING does not produce calibration curves, but merely timing distributions. This instruction overwrites the geometrical part of the data entered with TRACK, but uses the clustering type entered via the TRACK statement. Format: TIMING [ELECTRONS {electron | LAST | ONE-BUT-LAST | ... }] ... [TIME-WINDOW tmin tmax ] ... [X-RANGE xmin xmax] [Y-RANGE ymin ymax] ... [ANGLE-RANGE phimin phimax] ... [BINS bins] ... [ITERATIONS loops] ... [RUNGE-KUTTA-DRIFT | MONTE-CARLO-DRIFT] ... [NOATTACHMENT | ATTACHMENT] ... [WEIGHTING-FUNCTION weight] ... [NOKEEP-HISTOGRAMS | KEEP-HISTOGRAMS] ... [NOPLOT-OVERALL | PLOT-OVERALL] ... [NOPLOT-SELECTED-ELECTRON | PLOT-SELECTED-ELECTRON] ... [NOPRINT-OVERALL | PRINT-OVERALL] ... [NOPRINT-SELECTED-ELECTRON | PRINT-SELECTED-ELECTRON] If you don't manage to fit all this on a single line, remember that lines that end on an ellipsis are continued on the next. The PROGRESS-PRINT global option enables you to follow the progress of the computations. Example: TRACK MUON ENERGY 20 GeV TIMING ELECTRON 3 LAST Y-RANGE -0.3 +0.3 Computes the arrival time distribution of the 3rd and the last electron for random vertical Heed-generated tracks of 20 GeV muons in the y range [-0.3, +0.3]. The x-range is default, i.e. the x-portion of the AREA.
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Defines the track used by the DRIFT TRACK, TIMING, SIGNAL and various other instructions. A track in this context should be understood as the trajectory of a particle through the chamber. Tracks have two main aspects which also determine the format of the command: * location of the track: - For high energy particles, and sometimes also for graphical purposes, this would simply be a start and an end point. - Lower energy particles undergo multiple scattering and may also be stopped in the gas. It is therefore more appropriate to describe these by a starting point and an initial direction. If an end-point is specified when not appropriate, then it is used to compute the initial direction. - One may also, for some applications, request a point-track, i.e. a track of which start and end point coincide. This can sometimes be used as a poor approximation of a photon. * interaction with the gas: various models are proposed to describe the interactions of the particle with the gas: - FIXED-NUMBER: deposition of an electron or ion at regularly spaced intervals. This model has no physical meaning, but can be used to obtain a graphical representation of the drift field in the chamber. - EQUAL-SPACING: deposition of the mean number of clusters as specified in the gas section, at regularly spaced points along the track. The model has no physical meaning, but can be used to estimate the impact of cluster interval fluctuations. - EXPONENTIAL-SPACING: deposition of clusters of electrons at random locations along the track, respecting the information from the gas section. This model can be accurate, given good quality gas data. - WEIGHTED-DISTRIBUTION: deposition of an electron or ion over the track such that the positions are distributed according to a user specified function. - SINGLE-CLUSTER: a single cluster of electrons is generated per track at a random location along it. This model could be used as a rough approximation of a photon. - HEED: a simulation of the interactions between the particle and the gas using the Heed program. - further models can be added on request. Tracks are 3-dimensional objects. You may omit the z-component of the track, to indicate that the track is located in the (x,y) plane. However, multiple scattering may cause the track to leave this plane and delta electrons, Auger electrons and photons are generated irrespective of whether you specify a track located in the (x,y) plane or not. The model to be used is determined by the last keyword that is found on the line. If you set parameters for several models, then you can, to avoid ambiguity, type one of the keywords FIXED-NUMBER, EQUAL-SPACING etc at the end of the line. Otherwise, there is no need not type them since they are implied by the other keywords. Format: TRACK [ x0 y0 | x0 y0 x1 y1 | ... x0 y0 z0 | x0 y0 z0 x1 y1 z1 | ... FROM x0 y0 [z0] | ... { TO x1 y1 [z1] | DIRECTION dx dy [dz] RANGE range } ] ... [ FIXED-NUMBER ] ... [ LINES nline ] | ... [ EQUAL-SPACING ] | ... [ EXPONENTIAL-SPACING ] | ... [ SINGLE-CLUSTER ] | ... [ WEIGHTED-DISTRIBUTION ] ... [ WEIGHTING-FUNCTION { f | weight vs coordinate } ] ... [ SAMPLES nsample ] | ... [ HEED ] [ DELTA-ELECTRONS | NODELTA-ELECTRONS ] ... [ TRACE-DELTA-ELECTRONS | NOTRACE-DELTA-ELECTRONS ] ... [ MULTIPLE-SCATTERING | NOMULTIPLE-SCATTERING ] ... [ particle | MASS mass ENERGY energy CHARGE charge ] Examples: TRACK * * * 5 (Keep all old values except the y coordinate of the end point.) TRACK 1 1 1 2 2 2 (Defines a track from (1,1,1) to (2,2,2).) TRACK FROM 1 1 1 DIRECTION 0 0 1 RANGE 5 TRACK MU+ ENERGY 1000 LINES 10 MULTIPLE-SCATTERING NODELTA TRACK FIXED DRIFT TRACK TRACK HEED DRIFT TRACK (In a first TRACK statement, the location of the track is described. The length of the track projected onto the DIRECTION is limited to 5 cm. The second TRACK statement provides HEED with a description of the particle, indicates that multiple scattering should be taken into account, but not delta electrons. The same line changes the default number of deposits for the FIXED-NUMBER model to 10. The third TRACK statement selects the model to be used, a plot is made with this model, the model is then changed to HEED and another plot is produced.)
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Produces an x(t) plot: the relation between the position of a track and the drift time. This is a calibration curve used by the track reconstruction program. The XT-PLOT algorithm works as follows: 1. From around the selected wires (see SELECT), a number of drift lines are computed (see LINES) drifting them backwards from the wire. 2. The crossing points of these drift lines are determined with a series of lines at an angle to the y-axis (see the ANGLE parameter) and crossing the x-axis at regular intervals (see the X-RANGE and X-STEP parameters). The lines will be referred to as 'minimisation lines'. For each of the crossing points, the drift time is interpolated on the drift line. 3. On a subset (see the JUMP parameter) of the minimisation lines the 3 smallest drift times are kept, drift lines from the corresponding crossing points are computed to enhance the accuracy of the time estimate, and these 3 points are then used as start for a parabolic minimisation procedure with a limited number of iterations (see the ITERATIONS parameter) and which is declared to converge if the minimum drift time doesn't change much (see the EPSILON parameter). 4. The results are printed (see the PRINT-XT-RELATION parameter), plotted (see the PLOT-XT-RELATION and SCALE parameters) and output to a dataset (see the DATASET parameter). Note that there is another instruction in Garfield, ARRIVAL, that serves approximately the same purpose. The differences between XT-PLOT and ARRIVAL are summarised in the table below. As can be seen from the table, ARRIVAL provides more detail than XT-PLOT, which in return is faster. ----------------------------------------------------------------------- Aspect ARRIVAL XT-PLOT ----------------------------------------------------------------------- input complete gas tables, drift velocity and optionally clustering properties diffusion and Lorentz angle (spacing, cluster size) tables method Monte Carlo generation of parabolic minimisation of the tracks with clusters drift time over lines included drift velocity, Lorentz drift velocity, Lorentz angle, angle, diffusion, attachment, optionally also diffusion cluster spacing and size over the fastest drift line output mean, median and RMS of minimum drift time, diffusion selected electrons over the fastest drift line ----------------------------------------------------------------------- Format: XT-PLOT [DATASET dsname [member] [REMARK remark] ... [ANGLE angle] ... [X-RANGE xmin xmax] [X-STEP xstep] [JUMP jump] ... [ITERATIONS {YES|NO|itermax}] [PRECISION eps] ... [LEFT-ANGLE-RANGE lmin lmax] [RIGHT-ANGLE-RANGE rmin rmax] ... [PRINT-XT-RELATION | NOPRINT-XT-RELATION] ... [PLOT-XT-RELATION | NOPLOT-XT-RELATION] ... [SCALE min max] Examples: XT-PLOT XT DATASET lib.dat xt1 PRECISION 1E-2 (The second example will produce fairly quickly a crude x(t).)
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Use this command to write out the coordinates of the points used for the isochrones as a result of the last DRIFT command. This statement should be issued after the DRIFT command. Format: WRITE-ISOCHRONES DATASET dsname [member] [REMARK remark] Example: WR-ISO 'test data b' (Writes the isochrones to the VM/CMS dataset TEST DATA on the users B disk.)
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Writes the prepared track, see PREPARE-TRACK, right away to a dataset. It can later on be retrieved by GET-TRACK. This statememt should be issued after the PREPARE-TRACK command. Format: WRITE-TRACK DATASET dsname [member] [REMARK remark] Example: WR-TR 'disk$scratch:[pubzh.work.garfield]track.dat'
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