# This script generates a 2D Gmsh geometry for the ANASEN detector's wire planes, including an optional hot needle and IC wires. The geometry is designed for adaptive meshing, with finer mesh near the wires and coarser mesh in empty space. The script takes a z-locus as a command-line argument to determine the interpolation between the two wire planes. import numpy as np import gmsh, sys # --- Configuration Flags --- include_ic_wires = True include_needle = True gmsh.initialize() gmsh.model.add("adaptive_mesh") gmsh.option.setNumber("General.NumThreads", 10) # gmsh.option.setNumber("Mesh.Adapt.MaxNumberOfElements", 200000) # gmsh.option.setNumber("Mesh.Adapt.MaxNumberOfNodes", 200000) # gmsh.option.setNumber("Mesh.Adapt.MaxIter",5) # gmsh.option.setNumber("Mesh.MeshSizeMin", 5e-3) # gmsh.option.setNumber("Mesh.MeshSizeMax", 10.0) gmsh.option.setNumber("Geometry.Tolerance", 4e-2) # gmsh.option.setNumber("Mesh.MeshSizeExtendFromBoundary", 0) lc = 0.04 # z_loc = -174.3 if len(sys.argv) < 2: print("Usage: python3 wires_gmsh2d_bc.py ") quit() z_loc = float(sys.argv[1]) wireShift = 4.0 k = 2 * np.pi / 24.0 kg = k/2.0 # Plane 1 Offsets (-zmax/2) # Anodes: -6*k (base) - 4*k (correction) = -10*k offset_a1 = -6 * k - 4 * k # Cathodes: -6*k (base) + 0.5*k (half-placement) offset_c1 = -6 * k + (k / 2.0) # Guard wires: aligned with cathodes offset_g1 = offset_c1 # Plane 2 Offsets (+zmax/2) with Twist offset_a2 = offset_a1 + (wireShift * k) offset_c2 = offset_c1 - (wireShift * k) offset_g2 = offset_c2 # 1 needle, 24 ic1, 24 ic2, 48 guard wires, 24 anodes, 24 cathodes # needle at plane 1 at -zmax/2 no rotation xarr_needle = np.array([0]) yarr_needle = np.array([0]) # ic1 wires, plane 1 at -zmax/2 no rotation xarr_i11 = np.array([23 * np.cos(k * i) for i in range(24)]) yarr_i11 = np.array([23 * np.sin(k * i) for i in range(24)]) # ic1 wires, plane 1 at -zmax/2 no rotation xarr_i21 = np.array([23 * np.cos(k * i + k / 2.0) for i in range(24)]) yarr_i21 = np.array([23 * np.sin(k * i + k / 2.0) for i in range(24)]) # --- Coordinate Arrays (Plane 1) --- # Anodes: -k*i (Left-handed twist direction) xarra_1 = np.array([37 * np.cos(-k * i + offset_a1) for i in range(24)]) yarra_1 = np.array([37 * np.sin(-k * i + offset_a1) for i in range(24)]) # Cathodes: +k*i (Right-handed twist direction) xarrc_1 = np.array([42 * np.cos(k * i + offset_c1) for i in range(24)]) yarrc_1 = np.array([42 * np.sin(k * i + offset_c1) for i in range(24)]) # Guard Wires (48 wires, use kg spacing) xarrg_1 = np.array([32 * np.cos(kg * i + offset_g1) for i in range(48)]) yarrg_1 = np.array([32 * np.sin(kg * i + offset_g1) for i in range(48)]) # needle at plane 2 at zmax/2 xarr_needle_2 = np.array([0]) yarr_needle_2 = np.array([0]) # #ic1 wires, plane 2 at zmax/2 xarr_i12 = np.array([23 * np.cos(k * i) for i in range(24)]) yarr_i12 = np.array([23 * np.sin(k * i) for i in range(24)]) # #ic2 wires, plane 2 at zmax/2 xarr_i22 = np.array([23 * np.cos(k * i + k / 2.0) for i in range(24)]) yarr_i22 = np.array([23 * np.sin(k * i + k / 2.0) for i in range(24)]) # --- Coordinate Arrays (Plane 2) --- xarra_2 = np.array([37 * np.cos(-k * i + offset_a2) for i in range(24)]) yarra_2 = np.array([37 * np.sin(-k * i + offset_a2) for i in range(24)]) xarrc_2 = np.array([42 * np.cos(k * i + offset_c2) for i in range(24)]) yarrc_2 = np.array([42 * np.sin(k * i + offset_c2) for i in range(24)]) xarrg_2 = np.array([32 * np.cos(kg * i + offset_g2) for i in range(48)]) yarrg_2 = np.array([32 * np.sin(kg * i + offset_g2) for i in range(48)]) direction_needle_x = xarr_needle_2 - xarr_needle direction_needle_y = yarr_needle_2 - yarr_needle direction_ic1_x = xarr_i12 - xarr_i11 direction_ic1_y = yarr_i12 - yarr_i11 direction_ic2_x = xarr_i22 - xarr_i21 direction_ic2_y = yarr_i22 - yarr_i21 direction_guard_x = xarrg_2 - xarrg_1 direction_guard_y = yarrg_2 - yarrg_1 direction_anodes_x = xarra_2 - xarra_1 direction_anodes_y = yarra_2 - yarra_1 direction_cathodes_x = xarrc_2 - xarrc_1 direction_cathodes_y = yarrc_2 - yarrc_1 t = (z_loc + 174.3) / (2 * 174.3) # z=-174.3 is 0, z=+174.3 is 1 xloc_needle = xarr_needle + t * direction_needle_x yloc_needle = yarr_needle + t * direction_needle_y xloc_i1 = xarr_i11 + t * direction_ic1_x yloc_i1 = yarr_i11 + t * direction_ic1_y xloc_i2 = xarr_i21 + t * direction_ic2_x yloc_i2 = yarr_i21 + t * direction_ic2_y xloc_g = xarrg_1 + t * direction_guard_x yloc_g = yarrg_1 + t * direction_guard_y xloc_a = xarra_1 + t * direction_anodes_x yloc_a = yarra_1 + t * direction_anodes_y xloc_c = xarrc_1 + t * direction_cathodes_x yloc_c = yarrc_1 + t * direction_cathodes_y # wire_radius_a = 0.018 #mm # wire_radius_c = 0.0762 #mm # wire_radius_g = 0.0762 #mm wire_radius = 0.254 # mm needle = [] ic1_wires = [] ic2_wires = [] guard_wires = [] anode_wires = [] cathode_wires = [] iw1_tags = [(3, i) for i in range(24)] iw2_tags = [(3, i + 24) for i in range(24)] gw_tags = [(3, i + 48) for i in range(48)] aw_tags = [(3, i) for i in range(24)] cw_tags = [(3, i + 24) for i in range(24)] # for i,[xa,ya,xc,yc] in enumerate(zip(xarra_1,yarra_1,xarrc_1,yarrc_1)): # create Hot Needle (1 total) for i, (xn, yn) in enumerate(zip(xloc_needle, yloc_needle)): if include_needle: ndisk = gmsh.model.occ.addDisk(xn, yn, 0, wire_radius, wire_radius) needle.append(ndisk) # create Guard Wires (48 total) for xg, yg in zip(xloc_g, yloc_g): gdisk = gmsh.model.occ.addDisk(xg, yg, 0, wire_radius, wire_radius) guard_wires.append(gdisk) # create Cathode Wires (24 total) for xc, yc in zip(xloc_c, yloc_c): cdisk = gmsh.model.occ.addDisk(xc, yc, 0, wire_radius, wire_radius) cathode_wires.append(cdisk) # create IC Anode and Cathode Wires (24 total each) for i, (xa, ya) in enumerate(zip(xloc_a, yloc_a)): adisk = gmsh.model.occ.addDisk(xa, ya, 0, wire_radius, wire_radius) anode_wires.append(adisk) # Place IC wires only if flag is True if include_ic_wires: i1disk = gmsh.model.occ.addDisk( xloc_i1[i], yloc_i1[i], 0, wire_radius, wire_radius ) i2disk = gmsh.model.occ.addDisk( xloc_i2[i], yloc_i2[i], 0, wire_radius, wire_radius ) ic1_wires.append(i1disk) ic2_wires.append(i2disk) anasen_barrel = gmsh.model.occ.addDisk(0, 0, 0, 500, 500) # gmsh.model.occ.synchronize() # gmsh.model.mesh.embed(1,anode_wires+cathode_wires,2,anasen_barrel) gmsh.option.setNumber("Geometry.Tolerance", 1e-6) gmsh.option.setNumber("Geometry.OCCFixDegenerated", 1) gmsh.model.occ.synchronize() # --- Surface Extraction --- def get_surfs(disks): surfs = [] for d in disks: surfs += [ s[1] for s in gmsh.model.getBoundary([(2, d)], oriented=False) if s[0] == 1 ] return surfs needle_surfs = get_surfs(needle) if include_needle else [] gwire_surfs = get_surfs(guard_wires) awire_surfs = get_surfs(anode_wires) cwire_surfs = get_surfs(cathode_wires) i1wire_surfs = get_surfs(ic1_wires) if include_ic_wires else [] i2wire_surfs = get_surfs(ic2_wires) if include_ic_wires else [] all_active_wire_surfs = ( needle_surfs + gwire_surfs + awire_surfs + cwire_surfs + i1wire_surfs + i2wire_surfs ) gmsh.model.mesh.embed(1, all_active_wire_surfs, 2, anasen_barrel) f1 = gmsh.model.mesh.field.add("Distance") gmsh.model.mesh.field.setNumbers(f1, "CurvesList", all_active_wire_surfs) f2 = gmsh.model.mesh.field.add("Threshold") gmsh.model.mesh.field.setNumber(f2, "InField", f1) gmsh.model.mesh.field.setNumber(f2, "SizeMin", 0.05) # Fine mesh near wires gmsh.model.mesh.field.setNumber(f2, "SizeMax", 5.0) # Large mesh in empty space gmsh.model.mesh.field.setNumber(f2, "DistMin", 0.5) # Apply SizeMin within 1mm gmsh.model.mesh.field.setNumber(f2, "DistMax", 15.0) # Transition to SizeMax by 20mm gmsh.model.mesh.field.setAsBackgroundMesh(f2) # --- Physical Groups --- # Needle if include_needle: gmsh.model.addPhysicalGroup(1, needle_surfs, tag=1, name="hot_needle") # IC Wires if include_ic_wires: gmsh.model.addPhysicalGroup(1, i1wire_surfs, tag=2, name="ic_wire_1") gmsh.model.addPhysicalGroup(1, i2wire_surfs, tag=3, name="ic_wire_2") # Proportional Counter Wires gmsh.model.addPhysicalGroup(1, gwire_surfs, tag=10, name="guard_wires") gmsh.model.addPhysicalGroup(1, awire_surfs, tag=20, name="anode_wires") gmsh.model.addPhysicalGroup(1, cwire_surfs, tag=30, name="cathode_wires") # Gas Volume (2D) gmsh.model.addPhysicalGroup(2, [anasen_barrel], tag=13, name="gas") gmsh.option.setNumber("Mesh.Algorithm", 6) gmsh.model.mesh.generate(dim=2) # gmsh.model.mesh.refine() # gmsh.model.mesh.refine() gmsh.model.mesh.setOrder(2) gmsh.write("wires2d.msh") # gmsh.fltk.run() gmsh.finalize()