Interfaces and Plans

1
Interfaces and Plans

• October 2001

2
PST Internal Design/Prototypes

• Service panels
• Mechanical mockup being built
• Functional mockup(partial) to be ready for spring
  2002
• Detailed design of flanges and tubes can start
  shortly, some critical interfaces need better
  definition - see next slides.
• Prototypes Phase I(by spring 2002)
• Short sections of tubes
• Thermal mockups
• Prototypes Phase II
• Full-scale flanges, rails and tube. Forward or
  barrel is TBD.
• FDR date proposed - June 2002

3
Interfaces(1)

• SCT barrel
• Very recent proposal(last two weeks) of
  independent thermal barrier.
• Hence geometrical/envelope interface to PST is
  preliminary. Aim to freeze in detailed drawings
  by December but need to address thermal issues -
  see below.
• Reasonable understanding of impact on barrel SCT
  of forward PST but more FEA to be done by pixel
  team by December.
• In general, this is advancing well.
• Thermal Reliability
• Gas barrier at end of SCT forward with PST may
  leak or fail.
• Implications for humidity sensing
• Implications for rapid turn on of barriers
• Continuous operation feasible?
• Needs urgent action at ID level, will soon impact
  PST design

SCT Forward
Barrier
PST
4
Interfaces(2)

• Beam pipe
• Concept for 4-point, adjustable support proposed
• Joint FEA between pixel and beam pipe teams could
  start end of this month.
• However, need to understand feasibility of
  adjustment
• Must be done with pixels in place.
• Ideally would be done with pixels cold but is
  this required? Current design does not allow
  this, PP1 must be opened. Action - pixel team but
  need to agree on duration of survey.
• Direct visibility to beam pipe very poor.
• Is survey to targets on beam pipe needed or
  possible? Action - TC.
• Does activation allow sustained access so close
  to beam pipe? Action - TC
• Vacuum must be broken for survey? Action - TC
• Need urgent action at TC and pixel levels before
  investing substantial effort in detailed design
  of supports.

5
Interfaces(3)

• PST envelopes
• Barrel region - see previous. Adjustability
  requirement coupled with ID barrel
  adjustability(does it exist?).
• SCT forward region - OK. Appears sag, build
  tolerances OK, can live within current envelope,
  assuming adjustability within clearance.
• End PST/PP1 region needs better definition
• Required area of service bulkhead-type
  connections at PP1 exceeds possible area at end
  of tube only gt either add radial connections
  end or pass through some cables bulkhead
  connections. Study started by pixel team.
• However, thermal requirements in this region need
  better definition. Difficult to reliably heat PP1
  region around connectors. How are cold pipes from
  PP2 brought to PP1 to avoid condensation? Action
  pixel team but impact larger.
• Gas seal between PP1 and beam pipe adds to
  overall length.
• Move end-polymoderator to have better access to
  connections at PP1? This seems to be direction
  but need new envelope defined. Action ID/TC
• Likely to end up with PST/PP1 as long as possible
  to have better access to connections and to
  shorten path to services running to PP2.

6
Interfaces(4)

• Access to PST/PP1
• Activation will impose limits to access to
  PST/PP1 region
• Quick disconnects required? Action - pixel team
  but need activation estimates.
• Temporary shielding around TRT and beam pipe will
  surely be necessary. Must allow access to PP1.
  Action ID/TC.
• Installation
• Package delivery from surface appears feasible.
• More detailed work needed to define installation
  and test tube(ITT) dimensions. This has started
  by pixel team(Milano CERN)
• PST(flanges) to pixel detector
• Conceptual design proposed. Design of
  interface(endplate) to global support frame
  underway with goal of completion by December.

7
Planning and Organization

• In general, must improve communication among PST
  team(US), pixel integration(Milano CERN) and
  beam pipe/TC(CERN).
• Many interfaces to be defined in detail that
  drive PST design.
• Plan to start regular bi-weekly(weekly if
  necessary) meetings by phone/TV link. In-person
  meetings about every two months.