What is this tool and how is it used to study light?

[lightresearch]

Hi!
I'm doing a light research project and to have a refraction and reflection ( I don't know if it's like this in eglish) visual representation I came up with this photo. I don't know the name of this tool and also what is it made of? In my opinion is just a glass but I don't really know. Thanks!

 

[Doc Al]

Looks like this kit: Laser Refraction Tank

 

[robphy]

https://www.google.com/search?q=semicircular+prism
It could be glass, or plastic, or whatever liquid you might want to fill in http://www.carolina.com/physical-science-light-and-optics/semicircular-refraction-dish/754619.pr

and that's a protractor in the back.

 

[robphy]

What nice about the semicircular prism is that you can more easily study light from glass to air (compared to a rectangular prism).
From the semicircular side, aim the light source at the origin of the semicircle (the midpoint of the straight edge).
Since the normal direction at the semicircular interface is radial, the light from the source is undeflected (as is evident from the photo)...
so that one just has to handle the rays at the flat glass-to-air interface (as opposed to two or more sets using a rectangular prism).
One can explore total-internal reflection more easily.