Comments on Chapter 7

Non-trivial points tagged with (*)

(*) Title: The chapter contains little about installation and commissioning.
MT: very true, left out "commissioning" from the title for now

Fig. 7.1: Suggest to use a picture where all the cavern is in focus.
MT: will look for a better picture

(*)7.1: Suggest to add a few introductory sentences to say what services have to be integrated,
MT: added a few lines of the text here

line 2404: suggest change of "….on the side of the…. " to "… using guide rails attached to the HE back-flange.
MT: done

Also, say more about radiation levels to tie in with comments on rad-hard parts and radiation monitoring that come later in the chapter.
MT: radiation levels are discussed before in the document, in Sect. 6.1

Fig 7.3: Suggest to change label to "CMS HE back-flange showing GE1/1 chamber support rails."
MT: done

line 2406: confused by the phrase "there is no solid attachment to the CSC chambers"
MT: fixed

Fig 7.4: It is not clear where the slots are, so suggest to add arrows to show them.
MT: done

2424: what are the 'thermal effects' due to?
MT: modified this into "temperature changes"

(*) Suggest to say in one of these early sections what the operating temperature and stability requirement will be.
MT: issue to be explained still in the text. Temperature measurements will be performed in situ at the GE1/1 location during slice test. The GE1/1 working points can be tuned according to those measurements. Also, we will probably add temperature sensors to the chambers for the installation of the full system in LS2

2429: What does 'They' refer to? Could drop this sentence.
MT: fixed by dropping sentence

2432 and 2434: Avoid writing 'microradian' and 'micrometer' and write as usual abbreviated units. Check through the chapter (whole document worth checking) to use correct 'mu' symbol for 'micro' as 'u' is sometimes used, which appears sloppy.
MT: done

2435: here it would be appropriate to write 'millimeter' and not 'mm'
MT: done

2439: put references in order.
MT: done

2441: spelling of 'after'
MT: done

2442: add comma after 'chambers'
MT: done

2454: spelling 'cross-check'. Also, what is 'HW-alignment'
MT: fixed, replaced HW-alignment by "position monitor system"

2459-60: Confusing sentence. Unsure whether the distance between chambers has been enlarged in the model (since previous sentence refers to simulation) or in the design of the final system.
MT: rewritten, now it should be more clear one talks about the simulation here

(*) 2466: 'known techniques with advantages….' is vague. Please be more precise in what is the actual experience and what are the main advantages and disadvantages, if this can be explained briefly.
MT: in order to avoid going into too much detail, this particular sentence has been taken out

2468: what are the dimensions referring to? Also, 'independent' is better than 'independently'
MT: rewritten

2473: Drop 'The' from 'The careful…'
MT: done

2474: Which 'system' is being referred to? Not sure whether it refers to GE1/1 or the position monitoring system'
MT: indeed refers to position monitoring system; sentence rewritten

2478: Add comma after 'First'
MT: done

2485: Add comma after 'Then'
MT: done

2487: Suggest to write 'coordinate measuring machine (CMM)'. Writing 'CMM' first is jargon and the abbreviation here is unimportant as it is not used again later.
MT: done

(*) Section 7.2.2.4 is too dense and very vague on any given point requiring R&D or further development. Would like to see this sub-section expanded to say what specifically are the questions to be studied, and indicate the level of importance of the work.
GB: full section rewritten

2491: Avoid repetition of 'design'
MT: section rewritten

2496: spelling: 'modeling'
MT: done

2503: suggest to add 'For example," before "It is not…"
MT: done

2505: Change "almost individually" to "with much higher granularity" or similar phrasing to avoid repetition of granularity with next sentence. Also suggest to use 'foil' in singular as in following sentence.
MT: prefer to keep "individually", since "higher granularity" is too general. Also prefer to keep "foils" in plural, given one has 3 foils per chamber

Table 7.1: Suggest to adjust format to be placed further into this sub-section.
MT: modified this part a bit such that the table appears in the intro of the HV section

(*) 2512-13: Do not think it is appropriate to make a comparative statements including a named brand. Could simply drop the name. Also, where is it "described previously"?
MT: fixed; this was actually an old, forgotten sentence from a previous version of the document

2519: What is "UF/PNPI" ?
MT: University of Florida / Petersburg Nuclear Physics Institute; text modified

2524-2532: Suggest to move these introductory lines ahead of line 2512. There is no reference made in the text to Table 7.2. Presumably it is linked with this block of text and if so, the table should be moved closer to this sub-section.
MT: done

2549: Which 'system' is being referred to?
MT: HV system

2550 - 2554: appears to repeat what is contained in Table 7.2, but with different values! Please check and avoid repetition also.
MT: these lines were removed from the text, as all information is included in the table; values in the tables are correct

2555-2562: Giving precise dates is too detailed.
MT: fixed

2564: Add 'CAEN' before 'EASY'
MT: done

2571: use correct mu symbol for microTCA (as in 2583). Not clear to non-CMS reader what are 'USC crates', so could be better as 'backend crates in the service cavern (USC55)'.
MT: done

(*) 2576: Is 'radiation hard' fibre really needed? What wavelength is the optical link using and what kind of fibre? Note that BRIL, pixels, Tracker and ECAL all use off-the shelf "telecom" single-mode fibre for transmission at 1310nm, in a much harsher radiation environment, where the fibre was checked pre-production to be sufficiently radiation resistant (but it is certainly not considered rad-hard). If single-mode fibre is going to be used for the GEMs at the same wavelength, would expect that suitable standard fibre could be found. Note also that for these other readout systems in CMS the most important issue is the degradation of the lasers, not the fibre. Also, optical link systems have some margin included to compensate for losses at connectors, attenuation in fibre, etc.. Has this been incorporated into the design of the GEM readout also? It could be that the spec for such losses at connectors could as important as radiation effects, again negating the need for rad-hard fibre.
AM: the main reason to select radhard fibers is to ensure long term operation of the system beyond LS3; in principle it could also be done with non-radhard fibers; the type of fibers that we propose is now included in the text

2583: What is this 'telecommunication optical cable"? Please state with more precision the type of cable and its main features.
AM: details of this type of cable have not been decided yet

(*) Are there spare fibre channels in the system? (also spare channels for other services?)
MT: sentence was added about spares

Table 7.2: multiple comments: Add reference to this table in the text. Add spaces between values and units. Use proper subscript font size for subscripts. Use correct mu symbol for 'micro' Can 'TBD' be avoided for the ripple? Check consistency between these values and those quoted in the text and avoid repetitions.
MT: all fixed; also "TBD" has now been specified

Table 7.3: Suggest to use "opto-hybrid" instead of "optical hybrid"
MT: done

2585-6: Drop or add details. Maybe the design of the patch-panel is too detailed for this document.
MT: dropped for now

2589: replace 'shows the theoretical…' with 'shows schematically…" Also, add comma after "superchamber"
MT: done

(*) 2598-2612: Far too detailed! These are useful notes and diagrams for installation but this level of detail is not needed in the TDR. Suggest to put these details into an eventual cable-installation procedure document or other suitable internal note. Suggest to shorten these 3 paragraphs to the following text and remove figures 7.11, 7.12, 7.13: "The existing cable trays in the end-cap nose region are already completely full. A new routing is therefore been planned such that the GE1/1 services will follow the routing of the ME1/1 cooling pipes, where sufficient space remains.
MT: we agree it's detailed information, but since we have it available, we prefer to just keep it in the text for future reference

Table 7.4: Several comments: Volume figures overly precise. Use superscript correctly for m3. Suggest to merge all cells that share the same contents.
MT: all fixed

2615: Repeats what is written in Table 7.4.
MT: left this line in the text, since it is really basic information people are interested in

2626: Should not capitalize "tetrafluoromethane".
MT: done

2627: Use subscript in CF4.
MT: done

2617 and 2620: Use 'copper' in both cases.
MT: done

2621: Just to check: are the gas racks on X1 balcony or in the YE1 towers at X1 level?
MT: towers, text was modified

2625: 30 mm, suggest to add 'diameter'
MT: done

2626: Fix use of capital letters. Also, is 'Service' needed?
MT: done; dropped "Service"

2628: Drop redundant "At the moment"
MT: done

Figure 7.14: Replace with better quality figure, needs higher resolution.
MT: will try to fix this

Table 7.5: Add spaces between values and units. Figures overly precise Switch to kW where >> 1000 W
MT: done

2635-6: Use 'copper' instead of 'Cu'. Also, put in the missing details.
MT: done; if possible, more details will be added later on

Figure 7.15: Does having both top and bottom view add more useful info?
MT: we keep both views for completeness; just being practical: leaving out of the two views doesn't save us any space in the document

Figure 7.16: Hard to read. Details too small to be legible.
MT: will try to fix this

Figure 7.17: Replace with better quality figure, needs higher resolution. Spelling of "periphery".
MT: will try to fix this; spelling already corrected

2638: What is 'RBX'?
MT: HCAL readout box

2642: Add space between value and unit.
MT: done

(*) 2648: This Section on radiation monitoring does not seem to fit well in this chapter. It would fit better with some introduction of the radiation monitoring in the earlier part of the chapter. The radiation environment monitoring should include some figures of FLUKA results to be a more complete section. This links the spec and proposal of the monitoring system with the expectation for the intensity of the radiation environment.
MT: kept this section at the end of the chapter for now. Added some FLUKA dose simulation plots

A related comment (having not yet read the full document) is whether the radiation background rate is an issue for operation.
MT: no issue expected there; details on the radiation background can be found in Sect. 2.1 and 6.1

2646: RADMON needs a reference.
MT: done

2649: No need to capitalize "radiation-sensitive field-effect transistor."
MT: done

2652: Fix superscript "108"
MT: done

2653: Fix sub-script 1MeVeq
MT: MeVeq seems the usual notation, is it not ?

2654: Put reference in the references.
MT: done

2655: minimum setup? Is there inhomogeneity across super chambers that justifies the number of RADMONs.
MT: see phi dependence in the FLUKA plots that are included in this section

2656: What is "INRNE" group?
MT: the Sofia (Bulgaria) CMS group

Comments on Chapter 3/4:

- Table 4.3 : why are the data rates the same for both formats, for the tracking data ? do you mean that, for the tracking lossless, the zero-suppression is made in the optohybrid, instead of being made in the VFAT for the SPZS scheme ? but how is this rate of 0.17 Gb/s for the lossless data (for L1A of 100 kHz) consistent with l 1396 ? the tracking output data coming out from the optohybrid are not the ones that arrive on the MP7 ??
TDR change: The table has been corrected.

l 1400 : you could give more explanation on how this data reduction in the MP7 is made, and what is the data reduction factor.
TDR change: The TDR has been updated Comment to Reader: Neutrons and photons will typically hit one GEM of a superchamber. On the MP7 a LUT will be used to keep only pairs of hits correlated in time on both GEM of a superchamber and consistent with a muon track coming from the IP. One order of magnitude in data reduction should be reachable.