The WIMS multigroup scheme status and difference between versions

The WIMS programme for multigroup lattice calculations has been described elsewhere. The purpose of this memo is to indicate the present status of WIMS and in particular to point out the differences between different versions. Development is a continuing process with a code of this scope and different versions of the code are distinguished by a letter following the name WIMS. It has been the practice to make no change to a particular 'mark' of code once it has been issued, even to correct known errors, so that it is possible to guarantee replication of results. The version that was described by Roth is known as WIMS C. It is now working on the I.C.L. KDF9, and the IBM 7030 and 360 computers, WIMS D was developed by correcting known errors in WIMS C and by introducing new options, most of which were made specifically to facilitate reactor design calculations. Extensions to the leakage and burn-up calculations in particular should help to make YflMS D more suitable as an assessment tool. WIMS D is now working on the KDF9 and the 7030, while the $60 version is being brought up to WIMS D standard