how do I set the width of the xterm scrollbar

I'm running ubuntu 20.04. I've just obtained a new laptop with very high resolution (3840x2400) and so my xterm windows are tiny by default. I can increase the font size to compensate for the tinyness, but the scroll bar is still impossibly narrow. Could somebody tell me how I might widen it please?


I added the following lines to my .Xresources

 xterm*scrollBar: true
 xterm*rightScrollBar: true  
 xterm*Scrollbar*width: 14