1. Various Views From CAD Layout Emphasis on the relative locations of
CRT coverage
and
TPC Active Detector Volume

2. Legend – identification of parts
View from South (view in the Beam direction)
Overburden (first layer)
Top CRT (flat portion)
Side
Walls
Top CRT (angle portion, on the long sides)
Vent Duct
Vent Duct
Side CRT (long side in three sections, middle section slides in front of the upst and dnst sections thus a small horizontal gap between them)
Stairs to
Top of
Warm
Vessel
Mezzanine
Level
Active Volume (field cage)
Argon Volume (interior of cryostat)
Cryostats
Insulation
Warm vessel (dark red lines)

3. Legend – identification of parts
View looking west (Beam direction is left to right)
Side CRT (long sides – shaded areas)
upst section
middle section
dnst section
The sections overlap slightly
Top CRT (flat) (dashed line)
Top CRT (on north wall)
Top CRT (angle, long sides – shaded area)
Top CRT (on south wall, vertical portion)
Walls
Overburden (layer 1)
Cryogenics Area
Active Volume (field cage)
Argon Volume (interior of cryostat)

4. South wall – coverage on angled wall??
View looking west (Beam direction is left to right)
If the south wall Top CRT is placed on the angled portion of the wall, then there is a gap in coverage on the vertical portion wall, red circle on the left side below and illustrated by the yellow trajectory. This gap exists because of decisions to raise the ledge and in turn raise the elevation of the flat portion of the top CRT. But really this CRT panel location is wrong - - the angled portion of the south wall was never intended to hold Top CRT. Instead the short end walls just below the ledge hold top CRT panels in a vertical orientation – where the red and green circles are, and also as shown on the previous slide
Walls
Overburden
Cryogenics Area
Active Volume (field cage)
Argon Volume (interior of cryostat)

5. Play with Trajectories
View looking west (Beam direction is left to right)
Download this power-point, and play with the yellow lines, to show various cosmic particle trajectories.
Not as accurate as a Monte Carlo, but provides a basic view of overall coverage

6. Head Height on Access Stair
The skinny blue rectangle represents a 6-foot tall person standing on the access stair, just one step below the top of the detector
This particular diagram shows an angled CRT module on the angled wall - - but ignore that; it won’t be located there and even without it, there is only 6-ft of vertical height between the angled wall and the stairs
The stairs shown here are “standard” rise and tread width.
The tread rise and width can be adjusted to some extent, but past some point they cease to be called “stairs” in terms of what is allowed for a major egress passage, from a safety point of view
These stairs will be the main method of access to the top of the detector
A second access point on the opposite end is also being examined, but since it must be made to fit around the cryogenics also located there, this access is more likely to be a steeper ladder style of stair
Of more interest for today is the very skinny tan rectangle
The thin tan rectangle represents a Top CRT module, hanging vertically on the south upper wall.
The module clearly interferes with the stair access
Solution – don’t hang a module above the stair; come up with alternative coverage for this small gap
There are various other places where we will have small gaps – particularly on the north side where the cryogenics is located
South Mezzanine
And Access Stair

7. Rendered view Of the corner where the access stair is located
Various layers of the detector are shown “peeled back”. In reality we won’t be attaching TPC readout mini-crates (blue boxes, upstream end) onto the chimneys while a portion of the warm vessel roof is not yet installed (downstream end) The upstream end shows Top CRT “sample coverage”, with just a single Top-Angle panel, and just two rows of Top-Flat panels. The South Wall vertical panels show a necessary gap above the stairs which access the top of the detector
Rendered view
Of the corner where the access stair is located
Access stair, in the upstream west corner

8. Same viewpoint, zoomed in a bit more
Also note there is no attempt yet to show how the Side CRT is arranged on the South Side