tkinter - Make circle for radio button bigger

[Raptor88]

Running Python 3.6.  Using tkinter for GUI.

How can I make the circle for a radio button bigger?  I'm referring to the circle that the user clicks.  I can use padx and pady to put more space on the sides and above/below a radio button but that does not make the circle bigger.

On my 15 inch, 1920x1080 laptop screen, the circle is rather small and requires careful mouse cursor control to tick the small circle.  I want to make the circle twice the default diameter.

Here's some sample code in case it is necessary to answer my question:  

# ===== Right Frame and its contents =====
rightFrame = Frame(root, width=200, height = 600)
rightFrame.grid(row=0, column=1, padx=10, pady=2)

var = IntVar()

R2 = Radiobutton(rightFrame, text="0.2", font=(None, 16), variable=var, value=2, command=sel, padx=40).pack( anchor = W )

(There are 9 radio buttons but did not list them all since they are similar.)