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Original file (SVG file, nominally 600 × 600 pixels, file size: 47 KB)
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Summary
| Description |
English: Magnetic field of four coils creating a quadrupole field. This field configuration is used for strong focusing accelerator physics for instance. |
| Date | |
| Source | Own work |
| Author | Geek3 |
| Other versions | VFPt quadrupole coils 2.svg |
| SVG development |  This plot was created with VectorFieldPlot. |
| Source code | Python code# paste this code at the end of VectorFieldPlot 1.1
doc = FieldplotDocument('VFPt_quadrupole_coils_1',
width=600, height=600, unit=100, commons=True)
R = 1.2
rs = 0.5
ls = 0.4
field = Field({'coils':[
[-R, R, -pi/4, rs, ls, -1.0], [R, R, pi/4, rs, ls, -1.0],
[R, -R, -pi/4, rs, ls, 1.0], [-R, -R, pi/4, rs, ls, 1.0]]})
r0 = op.brentq(lambda r: field.F([0, r])[0], 0.1 * R, 2.0 * R)
Fs = ig.quad(lambda r: field.F([0, r])[0], 0.0, r0)[0]
n = 4
for i in range(n):
a = (i + 0.5) / n
r = op.brentq(lambda r: ig.quad(
lambda r1: field.F([0, r1])[0], 0.0, r)[0] - a * Fs, 0.0, r0)
for phi in range(4):
line = FieldLine(field, rot([r, 0], phi * pi / 2.0), directions='both')
doc.draw_line(line, arrows_style={'dist':1.3, 'offsets':[0.0, 0.5, 0.5, 1.0]})
for phi in range(4):
xy = rot([R, R], phi * pi / 2.0)
for d in (-1, 1):
xy1 = xy + d * rot([0.427, 0], (phi-0.5) * pi / 2.0)
line = FieldLine(field, xy1, directions='both')
doc.draw_line(line, arrows_style={'dist':1.3})
# draw coils
windings = 9
b = ls / (windings - 1.0)
coil_defs = doc.draw_object('defs', {})
grad_back = doc.draw_object('linearGradient', {'id':'grad_back',
'x1':'0', 'x2':'0', 'y1':str(-rs-b), 'y2':str(rs+b),
'gradientUnits':'userSpaceOnUse'}, group=coil_defs)
for of, col in ((0.00, '#ac7d6b'), (0.15, '#220e0b'), (0.35, '#8a634f'),
(0.60, '#ffffff'), (0.80, '#8a634f'), (0.90, '#371f18'), (1.00, '#a37e6b')):
doc.draw_object('stop', {'offset':str(of), 'stop-color':col}, group=grad_back)
grad_front = doc.draw_object('linearGradient', {'id':'grad_front',
'x1':str(-b), 'x2':str(b), 'y1':'0', 'y2':'0',
'gradientUnits':'userSpaceOnUse'}, group=coil_defs)
for of, col, opa in ((0.00, '#ad7d63', 0.90), (0.48, '#ad8169', 0.31),
(0.65, '#8f6050', 0.14), (0.83, '#844038', 0.42), (1.00, '#2d1412', 1.00)):
doc.draw_object('stop', {'offset':str(of), 'stop-color':col, 'stop-opacity':str(opa)}, group=grad_front)
wire = doc.draw_object('g', {'id':'wire'}, group=coil_defs)
wire_string = 'M -{0},{1} L -{0},-{1} A {0},{0} 0 1 1 {0},-{1} L {0},{1} A {0},{0} 0 1 1 -{0},{1} Z'.format(b, rs)
wire_back = doc.draw_object('path', {'d':wire_string, 'stroke':'none',
'fill':'url(#grad_back)'}, group=wire)
wire_front = doc.draw_object('path', {'d':wire_string, 'stroke':'#000000',
'stroke-width':'0.01', 'fill':'url(#grad_front)'}, group=wire)
coil = doc.draw_object('g', {'id':'coil'}, group=coil_defs)
for i in range(windings):
doc.draw_object('use', {'{http://www.w3.org/1999/xlink}href':'#wire',
'x':str(b * (2 * i + 1 - windings))}, group=coil)
doc.draw_object('use', {'{http://www.w3.org/1999/xlink}href':'#coil',
'transform':'translate(-{0},{0}) scale(-1,1) rotate(45)'.format(R)})
doc.draw_object('use', {'{http://www.w3.org/1999/xlink}href':'#coil',
'transform':'translate({0},{0}) rotate(45)'.format(R)})
doc.draw_object('use', {'{http://www.w3.org/1999/xlink}href':'#coil',
'transform':'translate({0},-{0}) scale(-1,1) rotate(45)'.format(R)})
doc.draw_object('use', {'{http://www.w3.org/1999/xlink}href':'#coil',
'transform':'translate(-{0},-{0}) rotate(45)'.format(R)})
doc.write()
|
Licensing
I, the copyright holder of this work, hereby publish it under the following licenses:
|
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License. |
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
- You are free:
- to share – to copy, distribute and transmit the work
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- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
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File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 22:24, 7 August 2010 | | 600 × 600 (47 KB) | Geek3 | VFPt_quadrupole_coils_1 |
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