Hi all,

During the last “Pixel ITk Mechanics and Integration” meeting we started the discussion about the overall mechanics.

In practice about what moves relative to what to meet the functional requirements.

As most of you might know, the functional requirements register has been worked out for Pixel. It has not been formally approved yet by but it is mature enough to be used. The latest and stable version is posted on our SharePoint (link at the bottom of this mail).

The impact to the integration sequence of the functional requirements is relevant and they can be roughly summarized as follow:

-          The need to reduce the radiation global dose delivered to the workers, together with the aim of Pixel project to be independent from strips assembly process, lead to foresee the integration of both outermost and innermost pixel layers on surface. The Pixel integration will take place as late as possible but on surface when the strip detectors are completed.

-          The removable layers (innermost replaced in situ ) must be designed such to minimize the time required for the replacement and the termination (distributed dose minimization).

 

Actually there are several concepts for the pixel local support. All of them had a bottom-up design approach. In practice engineers have designed mechanical structures to position modules in the space trying to meet local support specs (draft is also posted on the SharePoint below).

Before going too far into the design details it’s better to verify whether what we are designing meets the top level requirements (functional requirements) and understand the consequences to the integration process.

Such a compliance can be evaluated via a Top-Down design approach (more details in Eric’s talk here:  https://indico.cern.ch/event/343283/ ).

 

It’s therefore useful to go through a “cartoon engineering”  exercise for any local supports concept engineers are working at: Disc rings, I-beam, stavlet, alpine and Geneva.

I would like to ask groups to work out a sequence in PowerPoint (cartoon)  for each concept to be presented at the next meeting (it will end up to be in January since there is a cooling meeting at Cracow next week).

Cartoon should try to answer the basic question like:

 

FIRST INTEGRATION ON SURFACE

-          Integration concept: How the pixel-sub part (outermost, innermost, discs, etc) can be integrated in the strips

-          What the stave/disc concept would require: PST, IST or other structures

-          Kind of tooling required to install it

-          Possible services routing

 

INNERMOST LAYERS REPLACEMENT IN THE PIT 

-          How the support scheme looks like during insertion

-          What needs to come out with the innermost layers

-          How the design is compliant with the fast replacement and termination

-          Is the design compatible with splitting the layers in the middle?

 

and finally… HOW DOES ALL THIS MAP WITH THE HIGH ETA OPTION?

 

SHAREPOINT LINK  https://espace.cern.ch/atlas-itk-pixel-mechanics-integration/Shared%20Documents/Forms/AllItems.aspx

 

Hope the scope is clear enough. Please email me for any question…

Bye

D