Superconducting Magnet Victory

Point out news stories, on the net or in mainstream media, related to polywell fusion.

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WizWom
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Post by WizWom »

Tom Ligon wrote:Are you using a stock HTSC? Silver tape HTSC sandwich? We toyed with a sample but could never get Dr. Bussard interested enough to try building a magnet. Maybe history would be different now. I did manage to get a piece of it to levitate above a rare earth magnet, so I'm confident we had it in the superconducting range.
I think Bussard saw the same issue I see with HTSC vis-a-vis Polywell: for a functioning net power polywell, the magnetic field is well above the limits that these material remain superconducting. So any mucking about with them ends up being worthless when you go full scale.
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FAMULUS
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Post by FAMULUS »

Tom,

I'm using YBCO which seems to be capable of high magnetic fields:


http://www.magnet.fsu.edu/mediacenter/n ... gust7.html


also, thanks for the mention!

WizWom
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Post by WizWom »

Yeah, I think the HTSC materials available 5 years ago would have been topping out ~7 Tesla, this is a HUGE improvement, and makes a break-even device a LOT smaller.
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MSimon
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Post by MSimon »

Famulus,

Contact me. I have a friend who has some questions.
Engineering is the art of making what you want from what you can get at a profit.

MSimon
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Post by MSimon »

FAMULUS wrote:Tom,

I'm using YBCO which seems to be capable of high magnetic fields:


http://www.magnet.fsu.edu/mediacenter/n ... gust7.html


also, thanks for the mention!
The question not answered is : volume. Very high fields in very small volumes is not helpful.

BTW with constant capacity (current) windings the field goes UP with smaller volumes. Half the volume (assuming you can get the required eqpt into the field) gives 16X the power density. The volume goes down by 8X. Thus the power doubles by halving the coil size.

Given the confinement improvement smaller donut holes (for egress of reaction products) may not be a problem - except for the necessity of improved aiming of the electron guns (etc) that would be required.
Engineering is the art of making what you want from what you can get at a profit.

FAMULUS
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Post by FAMULUS »

M.Simon:

Assuming the donut hole is 1/3 the size of the donut... I calculated the following donut sizes:

Smaller size is more cost efficient.



minor_radius:2.0 mm
tape dimentions: 4.0 mm by 0.3 mm
major_outside_diameter:12.0 mm
TURNS:2.0
critical_current: 80.0 amps
Ampturns:160.0
b_field_at_center_of_coil:0.0502654824574367 tesla
tape required for one coil:0.0502654824574367 meters
tape required for 6 coils:0.00030159289474462 kilometers
cost for 6 coils:14.4764589477418 dollars
radius: 2.0, efficiency: 0.00347222222222222, B field: 0.0502654824574367, Cost: $14.4764589477418
_________________________________________________________________
minor_radius:3.0 mm
tape dimentions: 4.0 mm by 0.3 mm
major_outside_diameter:18.0 mm
TURNS:16.0
critical_current: 80.0 amps
Ampturns:1280.0
b_field_at_center_of_coil:0.268082573106329 tesla
tape required for one coil:0.60318578948924 meters
tape required for 6 coils:0.00361911473693544 kilometers
cost for 6 coils:173.717507372901 dollars
radius: 3.0, efficiency: 0.00154320987654321, B field: 0.268082573106329, Cost: $173.717507372901
_________________________________________________________________
minor_radius:4.0 mm
tape dimentions: 4.0 mm by 0.3 mm
major_outside_diameter:24.0 mm
TURNS:26.0
critical_current: 80.0 amps
Ampturns:2080.0
b_field_at_center_of_coil:0.326725635973338 tesla
tape required for one coil:1.30690254389335 meters
tape required for 6 coils:0.00784141526336012 kilometers
cost for 6 coils:376.387932641286 dollars
radius: 4.0, efficiency: 0.000868055555555556, B field: 0.326725635973338, Cost: $376.387932641286
_________________________________________________________________
minor_radius:5.0 mm
tape dimentions: 4.0 mm by 0.3 mm
major_outside_diameter:30.0 mm
TURNS:54.0
critical_current: 80.0 amps
Ampturns:4320.0
b_field_at_center_of_coil:0.542867210540316 tesla
tape required for one coil:3.39292006587698 meters
tape required for 6 coils:0.0203575203952619 kilometers
cost for 6 coils:977.160978972569 dollars
radius: 5.0, efficiency: 0.000555555555555556, B field: 0.542867210540316, Cost: $977.160978972569
_________________________________________________________________
minor_radius:6.0 mm
tape dimentions: 4.0 mm by 0.3 mm
major_outside_diameter:36.0 mm
TURNS:70.0
critical_current: 80.0 amps
Ampturns:5600.0
b_field_at_center_of_coil:0.586430628670095 tesla
tape required for one coil:5.27787565803085 meters
tape required for 6 coils:0.0316672539481851 kilometers
cost for 6 coils:1520.02818951289 dollars
radius: 6.0, efficiency: 0.000385802469135803, B field: 0.586430628670095, Cost: $1520.02818951289
_________________________________________________________________
minor_radius:7.0 mm
tape dimentions: 4.0 mm by 0.3 mm
major_outside_diameter:42.0 mm
TURNS:112.0
critical_current: 80.0 amps
Ampturns:8960.0
b_field_at_center_of_coil:0.804247719318987 tesla
tape required for one coil:9.85203456165759 meters
tape required for 6 coils:0.0591122073699455 kilometers
cost for 6 coils:2837.38595375739 dollars
radius: 7.0, efficiency: 0.000283446712018141, B field: 0.804247719318987, Cost: $2837.38595375739
_________________________________________________________________
minor_radius:8.0 mm
tape dimentions: 4.0 mm by 0.3 mm
major_outside_diameter:48.0 mm
TURNS:138.0
critical_current: 80.0 amps
Ampturns:11040.0
b_field_at_center_of_coil:0.867079572390783 tesla
tape required for one coil:13.8732731582525 meters
tape required for 6 coils:0.0832396389495152 kilometers
cost for 6 coils:3995.50266957673 dollars
radius: 8.0, efficiency: 0.000217013888888889, B field: 0.867079572390783, Cost: $3995.50266957673
_________________________________________________________________
minor_radius:9.0 mm
tape dimentions: 4.0 mm by 0.3 mm
major_outside_diameter:54.0 mm
TURNS:188.0
critical_current: 80.0 amps
Ampturns:15040.0
b_field_at_center_of_coil:1.04999007799979 tesla
tape required for one coil:21.2622990794957 meters
tape required for 6 coils:0.127573794476974 kilometers
cost for 6 coils:6123.54213489477 dollars
radius: 9.0, efficiency: 0.000171467764060357, B field: 1.04999007799979, Cost: $6123.54213489477
_________________________________________________________________
minor_radius:10.0 mm
tape dimentions: 4.0 mm by 0.3 mm
major_outside_diameter:60.0 mm
TURNS:226.0
critical_current: 80.0 amps
Ampturns:18080.0
b_field_at_center_of_coil:1.13599990353807 tesla
tape required for one coil:28.3999975884517 meters
tape required for 6 coils:0.17039998553071 kilometers
cost for 6 coils:8179.1993054741 dollars
radius: 10.0, efficiency: 0.000138888888888889, B field: 1.13599990353807, Cost: $8179.1993054741
_________________________________________________________________
minor_radius:11.0 mm
tape dimentions: 4.0 mm by 0.3 mm
major_outside_diameter:66.0 mm
TURNS:288.0
critical_current: 80.0 amps
Ampturns:23040.0
b_field_at_center_of_coil:1.31604172252198 tesla
tape required for one coil:39.8102621062899 meters
tape required for 6 coils:0.238861572637739 kilometers
cost for 6 coils:11465.3554866115 dollars
radius: 11.0, efficiency: 0.000114784205693297, B field: 1.31604172252198, Cost: $11465.3554866115
_________________________________________________________________
copy output
Program exited with code #0 after 0.17 seconds.
Last edited by FAMULUS on Thu Oct 28, 2010 5:36 pm, edited 2 times in total.

FAMULUS
Posts: 32
Joined: Tue Dec 23, 2008 12:02 am
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Post by FAMULUS »

ruby code for above calculations:



#!ruby

def body(minor_radius)
# units in mm
# minor_radius = 10.0
# major_radius = 100

tape_major = 4.0
tape_minor = 0.055

we rasterize the radius of the circle to the thickness of the YBCO, then we solve for the intersecrion of the each slice line and the circle

slice_count = (minor_radius / tape_minor).floor # slice count for one radius
slice_count += 1 if slice_count.odd? # force to be even so it's symmetrical

row_positions = slice_count.times.map{|slice| (tape_minor * slice) }

row_counts = row_positions.map do |row|
# puts "y:#{row}"
intersection = Math.sqrt(((minor_radius**2.0)- (row**2.0)))
columns_count_for_row = ((2.0*intersection)/tape_major).floor
end

row_counts = row_counts.reverse + row_counts #mirror to make the full circle


turns = row_counts.inject(0.0){|sum,n| sum+n}
major_radius = minor_radius*2.0
average_circumference = 2.0*Math::PI*major_radius
critical_current = 80.0
ampturns = (critical_current*turns)
magnetic_constant = (4.0*Math::PI * (10.0**(-7.0)))


b_field_at_center_of_coil = (ampturns * magnetic_constant) / (2.0* (minor_radius/1000.0))

dollar_per_meter_ybco = 48.0
cost = average_circumference*turns*6.0/1000.0*dollar_per_meter_ybco

puts "minor_radius:#{minor_radius} mm"
puts "tape dimentions: #{tape_major} mm by #{tape_minor} mm "
# puts "major_radius:#{major_radius}"
puts "major_outside_diameter:#{minor_radius*6} mm"
puts "TURNS:#{turns}"
puts "critical_current: #{critical_current} amps"
puts "Ampturns:#{ampturns}"
# puts "b_field_at_center_of_coil:#{format("%.6f\n",b_field_at_center_of_coil)}"
puts "b_field_at_center_of_coil:#{b_field_at_center_of_coil} tesla"
#
# puts "circumference:#{average_circumference}"
puts "tape required for one coil:#{average_circumference*turns/1000.0} meters"
puts "tape required for 6 coils:#{average_circumference*turns*6.0/1000.0/1000.0} kilometers"
puts "cost for 6 coils:#{cost} dollars"
# puts row_counts

# row_counts.each do |row|
# row.times{print "_" }
# puts "\r"
# end
return minor_radius,b_field_at_center_of_coil,cost

end

(2...12).each do |size|
result = body(size.to_f)
puts "radius: #{result[0]}, efficiency: #{result[1]/result[2]}, B field: #{result[1]}, Cost: $#{result[2]}"

puts "_________________________________________________________________"
end

MSimon
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Post by MSimon »

Thanks!
Engineering is the art of making what you want from what you can get at a profit.

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