PMM Control Simulator Module

Simulate the PMM board controller using equivalent operations performed on model resonators

In [1]:
from pmmcontrol.simulator import control, detector, hysteresis

control is a duplicate of the regular pmmcontrol module with functions modified to work with the resonator models.

detector contains the detector and resonator classes. A detector contains an array of resonators.

hysteresis contains the hysteresis model used by each resonator.

In [2]:
control = control.Control()

By default sets up a 9 by 10 configuration:

In [3]:
[control.rows, control.columns]

[9, 10]

control.selectMagnet() is run with several parameters:

def selectMagnet(self, row, column, isPrimary=True, isArrayMode=False, sign='positive')

  • row and column select the coordinates of the magnet begining with 0, 0
  • isPrimary tells the function whether we are using the large or small resistors
  • isArrayMode controls whether the function sets the current on all other magnets as well
  • sign is set according to whether we want to send a 'positive' or 'negative' current

In [4]:
control.selectMagnet(1, 1, True, True)


After running this command, the simulator generates 9 by 10 array of resonators - each with its own hysteresis model

The history of the currently selected magnet can be shown using control.showHistory()

In [5]:
%matplotlib inline

Currently there is no history because we have not set any current

To set current we use control.setCurrent(current) which takes current input in mA

First we will try to set the current too high...

In [6]:

ValueError                                Traceback (most recent call last)
<ipython-input-6-0392f1d4f3bd> in <module>
----> 1 control.setCurrent(50)

c:\users\jmmil\documents\mazin lab\pmmcontrol\pmmcontrol\simulator\ in setCurrent(self, current)
     65         if set_current > max_current:
     66             raise ValueError('The maximum current allowed on any magnet is ' +
---> 67                              str(max_current * 1000)[:5] + ' mA')
     69         # to achieve I current on current magnet, we send I/2 down the row and the column

ValueError: The maximum current allowed on any magnet is 45.19 mA

We are informed that the maximum current allowed on this magnet is $45.19$ mA

Now lets try setting it to something more reasonable

In [7]:


In [8]:

As seen in the history, the magnet saturated at around 1 mT

Hysteretic behavior can be seen when we decrease back down to zero current

In [9]:


In [10]:

Instead of following the same path on the return to 0 current, it returns to a nonzero magnetization

We can also see what happened to others magnets after messing with the target magnet at (0, 0)

In [11]:


This magnet is on the same row as the target magnet so it recieved compensating current in only one direction

In [12]:

Because we configured the controller in isArrayMode = True, compensating current was send down other rows to minimize the effect on other magnets that controlling our target magnet had

We should also check a magnet that recieved the compensating current in both directions

In [13]:

It is clear that all magnets besides the selected magnet were minimally affected

Let's look again at our magetized magnet

In [14]:

Even though we set the current back to zero, we have not eliminated the magnetization

To do so, we call resetMagnet(). This function decreases the current with an oscillating exponential

In [15]:

Reset complete.

The magnet has now been reset to zero magnetization. Because this was run with isArrayModel = False by default, other magnets on the same row and column were affected.

In [16]:

This means that after resetting a magnet, all magnets on the same row and column will be reset as well and must be reconfigured