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--- 184_projects:f21_project_5 [2021/08/19 14:57] – created dmcpadden
+++ 184_projects:f21_project_5 [2021/09/29 14:03] (current) – [Project 5B: Group Project TBD] dmcpadden
@@ Line 1: / Line 1: @@
 ===== Project 5 =====
+==== Project 5A: Mini-Particle Accelerator  ====
+S.P.A.R.T.A.N force, still trapped in the town of Lakeview, has been sent as part of a larger governmental team to work on developing a micro-particle accelerator on the outskirts of town. Why does a town the size of Lakeview need a micro-particle accelerator? You are not at liberty to say. Your team is tasked with modeling the initial part of the accelerator, which uses a constant electric field to accelerate the charges. The concept is that the particles will enter a tube that is encapsulated by rings of charge. Your team needs to demonstrate that this concept will produce a __constant__ electric field.
+=== Part 1: ===
+The first bit of code that you have received is from the previous team who were able to construct a single ring of charge and show the electric field due to that ring at some point. Your team should construct the electric field vectors for a circle inside the accelerator (smaller than the ring) at a distance of a few centimeters from the ring face.
+<code>
+GlowScript 2.7 VPython
+#Set up constants
+R = 0.02
+r_obs = 0.05
+Q = 1e-9
+N = 20
+dq = Q/N
+scale=1e-4
+oofpez = 9e9 #1/(4pi epsilon_0) in N m^2/C^2
+#Defining a ring at the origin
+myring = ring(pos = vector(0,0,0), radius = R, axis = vector(0,0,1), color = color.blue, thickness = 0.02*R)
+#Create an empty list for the charges
+ChargeList=[]
+#Set up the step size and angle for creating the charges
+dtheta = 2*pi/N
+theta = dtheta/2
+#Create charges in a circle and add them to the ChargeList
+while theta < 2*pi:
+    rpiece = R*vector(cos(theta),sin(theta),0) #location of piece
+    particle = sphere(pos = rpiece, radius = R/20, color = color.yellow)
+    ChargeList.append(particle)
+    theta = theta + dtheta
+#Create an empty list for the observation points
+ObsList = []
+#Set up the step size and angle for creating the observation points
+phi = 0
+dphi = pi/4
+#Create observation points in a circle and add them to the ObsList
+while phi < 2*pi:
+    r_obs_piece = r_obs*vector(cos(phi),sin(phi),1) #location of piece
+    obs_particle = sphere(pos = r_obs_piece, radius = R/20, color = color.red)
+    ObsList.append(obs_particle)
+    phi = phi + dphi
+#Find the electric field at each observation point
+for obs_point in ObsList:
+    for charge in ChargeList:
+        Enet=vec(0,0,0)
+</code>
+=== Part 2 ===
+After you got this initial code working, your team was able to construct a model of a tube consisting of multiple rings, all with the same charge. But, the field doesn't look quite right - it's not constant as expected. Your bosses seem to think the field can be made constant in the tube, so it's up to you to figure out how.
+<code>
+num_points = 10
+num_rings = 11
+N = 11
+spacing = 0.02
+# Set some constants and stuff
+R=0.02 #radius of ring in m
+ax = vector(0,0,1) # simplify things
+Q=1e-9 #charge of ring in C
+oofpez=9e9 #1/(4pi epsilon_0) in N m^2/C^2
+#draw axis
+zaxis=cylinder(pos=-2*R*ax, radius=0.015*R, axis=4*R*ax, color=color.black)
+#draw points
+points = []
+for i in range(num_points):
+    xr = 0.01*sin(i*2*pi/num_points)
+    yr = 0.01*cos(i*2*pi/num_points)
+    points.append(sphere(pos=vector(xr,yr,0.01), color=color.red, radius=5*zaxis.radius))
+#make and draw rings
+rings = []
+ring_charge = [Q,Q,Q,Q,Q,Q,Q,Q,Q,Q,Q]
+for i in range(num_rings):
+    loc = i - (num_rings)//2
+    rings.append(ring(pos=vector(0,0,spacing*loc), radius=R, axis=ax, color=color.blue, thickness=0.02*R))
+# Find net field
+for apoint in points:
+    Enet = vector(0,0,0)
+    for i in range(len(rings)):
+        aring = rings[i] # look at one ring
+        dq = ring_charge[i]/N #charge of a piece
+        dtheta = 2*pi/N #theta increment for our loop
+        theta=dtheta/2 #initial theta for first piece of loop
+        Ering = vector(0,0,0) #net electric field for single ring
+        rpoint = apoint.pos
+        scale=1.2*mag(rpoint)/8000 #used to scale the arrows representing E-field
+        while theta<2*pi:
+            rpiece = R*vector(cos(theta),sin(theta),aring.pos.z/R) #location of piece
+            r = rpoint-rpiece #vector from piece to point in space
+            rmag = mag(r) #magnitude of r
+            rhat = norm(r) #unit vector for r
+            dE = oofpez * dq / rmag / rmag * rhat # Electric field of peice of ring
+            Enet = Enet + dE
+            particle=sphere(pos=rpiece, radius=apoint.radius, color=color.yellow) #draw a particlee
+            theta=theta+dtheta
+    Evector=arrow(pos=rpoint, axis=scale*Enet, color=color.orange, shaftwidth=apoint.radius/2)
+</code>
+/*
 ==== Project 5A: Maverick and JPL ====
@@ Line 20: / Line 150: @@
 </WRAP>
+*/
+/*
 ==== Project 5B: Group Project TBD ====
+*/