Adjust the field of the magnet by the value of ``scalingFactor``.  The adjustment
        is multiplicative, so a value of ``scalingFactor = 1.0`` will result in no change
        of the field.

def setField(self, new_value):
        """
        Adjust the field of the magnet by the value of ``scalingFactor``.  The adjustment
        is multiplicative, so a value of ``scalingFactor = 1.0`` will result in no change
        of the field.
        """
        self.B = self.B._replace(val=new_value)