MCNP - Tallies definition with "<"

[19matthew89]

TL;DR Summary

Examples of tallies definition with logical operator "<" but I don't know what it means.

Hi everyone,

In MCNP manual there are often examples of Listing containing examples of tallies which have, in the definition of the cells/surfaces of the tally itself, the "<" symbol. I could not find in the document any reference to the use of logical expression in the definition of tallies (assuming "<" is actually used as a logical operator).

Could you please tell me what it means?

Referring to the last version of the manual (MCNP® Code Version 6.3.0 Theory & User Manual) the first example of use in a Listing is for Listing 5.13 but it appears in several other listing (e.g. Listing 5.51 or Listing 6.2).

Thanks a lot in advance.

 

[Alex A]

I actually stared at the example for about 10 mins completely clueless, before realising I'd used these myself. That is a such an unhelpful fragment. < means within and [x y z], which you'd commonly see with it, means part of a lattice. They are for specifying elements in repeated structures built with universe/fill.

See "5.9.1.5 Repeated Structures Tallies" for not a great explanation.

 

[19matthew89]

Thanks a lot!