# INITIAL COOLING CHANNEL ENGINEERING DESIGN AND COSTING STUDY

### Engineering Design Requirements:

The basis for the design represented on fig. Super FOFO LATTICE 1 and
Super FOFO LATTICE 2 are the data on the "INITIAL PARAMETERS FOR STUDY 2
-- DESIGN A - - DRAFT 4 ", Section 2.11 Cooling LATTICE and section 2.12
Cooling RF and absorbers.

The data was plotted as a geometric boundary parameter outlining a
vertical cross section of the channel components.

### Design Development:

Ones the lattice channel components boundary parameters were
established, this being location and since of super conducting solenoid
magnets, Rf cavity and liquid hydrogen absorber, the supporting elements
consisting on outer pressure vessel (vacuum chamber) with supporting
structure, cryostat enclosures for the super conducting solenoids and
the liquid hydrogen absorber vessel were laid out taking in account the
space requirements for: a) assembly and disassembly feasibility, b)
structural support strength capability, c) accessibility for connections
of electric power, instrumentation, cryogenic ducting and insulation.

**Design criteria:**

The logical approach to the design is of this hardware is by it's
functionality that suggest a modular construction. Each physical lattice
is compose of 2 modules to facilitate assembly and strengthening the
mechanical stability of the lattice components particularly the super
conducting solenoids that generate large Peak Field Stresses.

The **main module** consisting of the RF cavity surrounded by the
coupling field magnet located on the lattice longitudinal geometric
center, this is the larger of the 2 modules consequently the vacuum
chamber is built with the support structure for the entire assembled
lattice, also it is split to assemble the coupling field magnet, this
magnet will be pre assembled with its own cryostat and vacuum chamber as
a package.

The **second module**, contain the liquid hydrogen absorber and the 2
short solenoid focusing magnets. The 2 solenoids are also packaged as a
unit, enclosed inside of a common cylindrical cryostat containing
shielding and thermal dividers. This tubular cryostat is constructed
with a transverse lined clearance hole that allows duct connections to
the liquid hydrogen absorber. The absorber is installed through the bore
of the magnets cryostat and positioned on the cryostat geometric center
with its connecting ports lined up with the transversal access holes of
the cryostat.

From all of the components considerable effort has being expended on the
design of the **liquid hydrogen absorbers** with emphasis on safety. The
absorber window thickness requirement imposes careful consideration on
all the design aspects of which: factors of size, operating pressure and
material of construction are still under study. Preliminary ANSYS
analysis using the material properties corresponding to aluminum 6061-T6
indicate that windows shaped with tapered wall thickness will allow the
minimum thickness, specified in the study 2 report, at operating
pressures between 1 to 2 atmospheres. Farther analysis promises strength
optimization capabilities by combining configuration with material
properties beyond the customary design standards.

A short survey of vendors for the fabrication of this windows show that
regardless of the method of construction, fabricators hesitate to commit
assurance in the quality and accuracy of thickness under 0.015" (381m)
dimension, one of their main concerns is the possibility of finding
voids or bubble inclusions in the material and this apply to all the
candidate materials.

Currently the effort at the Mississippi University, intents to
investigate simpler methods of fabrication that include chemically
thinning the material, this will avoid the stress residues on the finish
product at the finishing stages typical of machining or forming by all
the currently known methods.

AlBeMet162 material appear a desirable choice for the construction of
the absorber windows because of its composition (65 % beryllium 35 %
aluminum) may allow us to construct thicker window walls, which will
take care of the potential void inclusions, and because of its higher
tensile strength that will allow flatter configuration favorable for the
beam and hydrogen dynamics.

We shall take in account the fact that AlBeMet162 does not follow the
processing procedures of Aluminum just because it has the Aluminum
chemical component in its composition.  This is a two-phase material of
(Be) and (Al). for which the prototype manufacturing investigation with
the aluminum along may not directly apply to AlBeMet162; there fore, a
parallel effort on the window design with this material shall be
programmed

### Cost:

An intent was made to include all the foreseeable elements in the
SuperFOFO cooling channels design for the estimate of costs based on the
current requirements specified on the study 2 report, as represented on
the layouts attached; however, the layouts as well as the cost estimates
shall be considered as preliminary, in consideration to the multitude of
engineering detail not represented yet requiring farther clarifications
of physics requirements as well as engineering effort.