More comments today 12-1-2015: HI I do mot know how useful this comment will be, but, as you know, I fully agree with the first and last paragraph of the Joel comment. My compliments anyway the best to all F.

I have only a few suggestions. Since this will be submitted to various review committees and form the basis of proposals to funding agencies, I think it would be best to always lead with the improvement GE1/1 brings to the trigger and tracking performance. This is based on a simple, easy-to-understand, argument and constitutes “added-value”, even if the existing CSC detectors continue to work well. Usually, the proponents do lead with this argument but sometimes they instead emphasize the “redundancy” aspect, especially if the performance of the CSCs begins to degrade after many years of service. While that may well happen and the possibility does need to be included in the GE1/1 justification, that may not happen or there may be other ways of dealing with that. ......................................... Finally this is a very thorough document with a lot of technical detail that is familiar to the authors. In some cases, it is very hard for someone who is not part of the effort to understand what is being presented. Figures with a lot of detail should be accompanied by explanations in the text or the caption of what the important points are. Conclusions that are supposed to be taken away should be very clearly stated.

Previous Comments:

As a general comment I find the TDR is well written but unusually long : 176 pages .In the MU TDR of 1997 the Barrel and Endcap chamber systems were described in 100 pages each. And background etc was 20 pages.. The text includes too many details (e.g. 4 pages are dedicated to the Management, frequency and type of meetings etc….) and several repetitions. The reading is very time consuming.

I have a short list of comments/or curiosities/or things that I do not understand

Chapter 1 Line 197 threshold for displaced Muons is said to be “higher”…Why? Higher of what ? and how much?

Line 211 I understand that charge is “deposited” on finely segmented electrodes .In lines 279-280 the charge is induced ……

Chapter 2 Paragraph 2/3/4 Stretching…page 39 .in the full paragraph no figure is given for the tension to be applied. I suspect that this tension will not be the same along the chamber perimeter and that the operation of stretching might be a delicate ingredient. Gradients in the tension can generate waves on the foil surface etc……no result is shown on some rough test that could give confidence on a non time consuming operation This seems to me too vague……there is no figure of the value of the tension but ,en passant , in line 722…(1N/cm) but this is 8 pages before…..

Line544 speaks of B=3T and of an angle of 8~9 deg wrt the chamber perpendicular So the field is ~ parallel to the drift path. In line 551 the chamber is installed on the M1 magnet of 3 T . Than Fig 2.18 seems to indicate a B/E angle of 60 or 80 deg with a B of 1 T or less generating a displacement of millimeters : this is confusing me. Which is the logical relation in between the sentence in line 544 and the fig 2.18?

Lines 560-563 how can you reach that conclusion on the base of the shown figures 2.18?

Chapter 4 Line 1325 and table 4/3. The trigger fast or rate of 0,05Gbs .How this rate compares to the 5 KHz/cm^2 quoted in line 301?

Chapter 5 Line 1428 Chapter 5 a good chapter and well detailed but with no indication of the time to be spent in each step of the construction commissioning sequence .

Line 1598 : installation and stretching …but than there is no mention of stretching

Lines 1606-1607 when the chamber is over pressurized the gas tightness is given by what :the final covers or the read out and drift plane as shown in fig 2.37 page 36.? I could not find the thickness of those planes….Which is the reason for a choice of 20 mb? In the experiment the chamber is operated at constant pressure or at atmospheric pressure ? : I do not remember finding some indication….

Chapter 6 Line 1788 and fig 6.1 and 6.2 A Superchamber consists of two chambers,,,a bkg particle may generate a signal in only one. Figure 6.3 is the AND or the OR ?

line 1804 : here what is a detector signal? a couple of hits in the Superchamber or one hit in one of the two chambers. I find this unclear, but might be relevant for bkg ?

Fig 6.8 and line 1941 in the text you say that curves are shallow for “close” while it seems to me that curves are shallower for “far”

Chapter 7 Fig 7.6 and line 2592 ; in spite of the (very) detailed description I do not understand how can the positioning plates be glued precisely to the Read O B while the ROB is covering them?

-- ArchanaSharma - 2014-12-09