Design of an Antimatter Large Acceptance Detector In Orbit (ALADInO)

Round 1

Reviewer 1 Report

The publication    presents a very    well written and complete overview of the    status of the art of precision  particle physics measurements with detectors in  space. The review is very well referenced by the set of    
bibliographic information. The prospects for future measurements by a new detector are then described, together with a possible design of the detector including various technology options.
A few more  details could have been added on some of the planned experimental procedures and the expected possible issues and systematics, and on the data analysis expected results.
Although it's clear that the paper is intended mainly as a summary of the ideas and the prospects for further R&D activities for the design of an experiment, to be carried on in the coming years.

Please find below very few minor comments:

- Figure 1: in the caption weigth -> weight

- line 187: is there a reference to published results, or direct link or reference to the conference talks
where this results have    been shown ?

- line 189: is there a published reference that could be cited ?

- line 196: properties is -> properties are

- Figure 2: six plane -> six planes

- line 334: the trigger prescales and data reduction algorithms should be detailed a bit more

- section 4.1.2: in this section the expected single layer resolution is discussed
but there is no mention of the alignment methods.
Are the alignment uncertainties expected to be under control, over the full data taking period ?
Maybe some reference to alignment  procedures and related systematics in previous experiments could be added ?

- line 832: MIP    or MeV ?

Author Response

replies to the reviewer in the attached file

Author Response File: Author Response.pdf

Reviewer 2 Report

Brief Summary

The paper details the instrumentation of the next-generation in-orbit magnetic spectrometer, which will enable the accurate measurement of high-energy cosmic rays in L2. The first chapter provides an overview of the current CR detectors, limitations, and future technological preferences. The second chapter shows why anti-matter in CRs is an interesting channel to probe dark matter and baryogenesis. Chapter 3 gives detailed expectations on different physics channels: electron/positron (sensitivity above 100GeV), antiproton(O(100) statistics with extended energy range), antideuteron and antihelium(first spectrum and first detection). Chapter 4 features the ALADInO technology, in the context of its baseline design, and beyond. The design of its major components: spectrometer, calorimeter, and ToF detector are provided with references to current technologies and simulations. Power and mass budgets are given considering the limitation from its space vector deployment in L2.

General concept comments

The authors made a detailed and solid proposal on the cosmic ray detector, which utilizes the superconducting magnet to provide the required bending power to probe high kinetic CR flux. With the leap owing to the mature of High-Temperature Superconductor, it seems like the development of HTS is also the bottleneck for reaching the science goal, which requires further study in the future. Other systems for the detector seem to require minimum R&D efforts with heritages from the previous endeavor.

Figures: Re-usage of figures from Exper.Astron. 51 (2021) 5, 1299-1330 needs to be properly cited. 

Specific comments

L200: “of nuclear recoils in cryogenic”, add electronic recoils, microwave photons.

L212-214: “As of today, … acceleration and propagation.” Reference needed.

Fig.2: It would be more intuitive if the author can provide a simulated track with the detector design, or show the claimed 10m^2 sr with an acceptance cone.

L312-313: Please rewrite the bracket in a separate sentence.

Fig.3:

1) The legend in the right plot is too small to read. Use bigger fonts or keep the reference in the caption.

2) Since AMS02 will be collecting more data prior to the deployment of the ALADInO pathfinder, in at least one of the figures, it will be nice to present their projection till 2028 (Fig. 44, Phys.Rept. 894 (2021) 1-116).

Fig.5: What are the red data points following the BG band in the left plot?

L529: Please add a reference to ReBCO.

L684-686: “Is worth…the apparatus.” I don’t understand this sentence.

L718: Please define “ASIC”

L758: Please define “CMOS” and add to abbreviations.

L796-798: Why is the given specification of LYSO competitive? What are the alternatives?

L974: Please add the reference to the CERN SPS beamline.

L1009: What’s the peak power consumption of the cryogenic system, before reaching the equilibrium?

Decorations

L23: late 2000s -> the late 2000s

L123: Morever->Moreover

L132:is usually->are usually

L173:is only->are only

Fig 1: weigth->weight

Fig.2 six plane->six planes

L492: on ground->on the ground

L610: cosmic ray-> cosmic-ray

Fig.5: without largely impact-> without largely impacting

L786: isotropically-> isotropocally on

L876 and later: cristals->crystals

L877: been be defined->been defined

L1040 and later: envised->envisaged

L1063: and and->and

L1076:in 2030s->in the 2030s

Author Response

replies to the reviewer in the attached file

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Many thanks to the authors for their replies and changes to the text.

I think the manuscript has sufficiently improved to warrant publication.

Reviewer 2 Report

I really appreciate the authors' efforts to address the comments from the last round of the review. I can see the improvements in the clarity of the text and great efforts in making better/more informative figures. I appreciate the extra information provided in the authors' responses, which makes sense to me.

I recommend this version of the paper for publication.