• Reviewer 4
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Grade: 8

Title: Enhancing Band 10 Aperture Efficiency: An Active Mirror Study (PI: Kumara)

1. Alignment with NA ALMA Partnership strategic goals;

Comment: Improving aperture efficiency should extend the technical capability and improve the operation efficiency of ALMA.

2. Strength of the scientific case for the proposed ALMA upgrade concept; Comment on the relevance to the ‘ALMA 2030’ development documents.

Comment: Among the ALMA 2030 development paths, this study contributes to the "gains in speed" although it does not directly address the bandwidth or receiver sensitivity per se. This would be true for all Bands and not just Band 10.

3. Quality of the upgrade conceptual design;

Comment: This proposal aims to explore surface accuracy improvement via an active mirror correction system. Among the three specific ideas stated for exploration (deformable sub-reflector, flat active mirror, and "magic box"), only the deformable sub-reflector concept includes any details at all, and even there it is not clear whether the technical can be scaled up in frequency -- investigating that in detail would be a good project. The other options lack sufficient details to offer any notion on the merit of those approaches.

4. Readiness for production in the context of the ALMA Development Plan (the aim is to support a range of upgrades including both those which can be implemented rapidly and those requiring longer-term research and development);

Comment: It is difficult to predict what outcome can be reasonably expected and how those results will translate to the "production" -- a long term research project, perhaps.

5. Strength of the consortium organization (if applicable);

Comment: good

6. Qualifications of the key personnel of the Study;

Comment: good

7. Technical expertise, past experience (also in series production, if relevant) and technical facilities in the Institutes taking part in the Study;

Comment: good

8. Assessment of the level of risk inherent in the design;

Comment: the level of risk would be considered "high" in this case since it is not clear what outcomes the examination of the "flat active mirror" and "magic box" optics would yield.

9. Strength of the Scientific Team supporting the Study;

Comment: the "expert advisory panel" associated with this proposal is a distinguished group of experts.

10. Level of support guaranteed by the Institutes;

Comment:

11. Budgeted cost of the Study;

Comment: modest and appropriate for the effort stated

  • Reviewer 6

Grade: 4

Title Enhancing Band 10 Aperture Efficiency: An Active Mirror Study by Sridharan Kumara

Alignment with NA ALMA Partnership strategic goals.

The study could potentially lead to increase of observing efficiency at Band 10. It strengthens the North American radio astronomy community by nurturing relationship with private institution in pursuit of common astronomical interests.

Strength of the scientific case for the proposed ALMA upgrade concept. Comment on the relevance to the ‘ALMA 2030’ development documents.

The main science case is to improve the throughput and efficiency of Band 10 science observations, potentially doubling the amount of time available on source. No specific science was addressed, nor was a science case presented that is not possible to do now (due to prohibitive time constraints) which would become a possibility with the realization of such an upgrade. Quality of the upgrade conceptual design This is an exploration. It is unclear why these three particular concepts were chosen, and what will happen as a result of the literature review.

Readiness for production in the context of the ALMA Development Plan (the aim is to support a range of upgrades including both those which can be implemented rapidly and those requiring longer-term research and development)

Very far away from production. Strength of the consortium organization (if applicable)

There is an advisory panel, which consists of 2 SMA scientists/engineers. There does not appear to be any interaction with NRAO or ALMA. Qualifications of the key personnel of the Study

The proposal project is based entirely on the PI’s work, an astrophysicist with SAO on the SMA.

Technical expertise, past experience (also in series production, if relevant) and technical facilities in the Institutes taking part in the Study.

PI has experience with the holographic surface measurement for the SMA, and techniques for alignment of the optical chain. Seems applicable Assessment of the level of risk inherent in the design

Low level of risk. Strength of the Scientific Team supporting the Study

Seems strong. Level of support guaranteed by the Institutes

There is one half month of in kind labor contributed. Budgeted cost of the Study

The cost is small, consistent with the exploratory nature of the study.

  • Reviewer 9
Grade: 4.5

Title: 546 - Enhancing Band 10 Aperture Efficiency: An Active Mirror Study

1. Alignment with NA ALMA Partnership strategic goals;

Directly aligns with goals 1.1, 2.1, 2.2, 4.2, 5.1

2. Strength of the scientific case for the proposed ALMA upgrade concept; Comment on the relevance to the ‘ALMA 2030’ development documents.

The proposal aims to conduct a short, preliminary conceptual study of possible designs for an active mirror system that will be used to improve the surface accuracy of the ALMA dishes, increasing the efficiency of high-frequency observations (in particular band 10 observations). Band 10 availability is currently very limited due to site weather constraints, and this proposal has the possibility to significant increase the observing efficiency and thus availability of this band. However, the overall impact may be somewhat limited compared to other studies that will impact a broader segment of the ALMA user base.

This proposal indirectly addresses the ALMA development goal of enabling gains in observing speed - while this goal is primarily focused on increasing bandwidth and receiver sensitivity, improving the surface accuracy also helps to achieve this goal.

3. Quality of the upgrade conceptual design;

Overall very strong.

4. Readiness for production in the context of the ALMA Development Plan (the aim is to support a range of upgrades including both those which can be implemented rapidly and those requiring longer-term research and development);

This is the first in a planned three-phase study, here focusing on evaluating possible concepts and selecting one for full design in the second phase. This project will lay important groundwork toward the eventual development of an active mirror system.

5. Strength of the consortium organization (if applicable);

N/A.

6. Qualifications of the key personnel of the Study;

Overall very strong. The PI is the recognized expert and leader of studies involving the SMA surface accuracy, and has the relevant expertise and experience. It’s unclear why the supporting personnel are included in an “advisory panel” capacity rather than study co-I’s.

7. Technical expertise, past experience (also in series production, if relevant) and technical facilities in the Institutes taking part in the Study;

See #6 above.

8. Assessment of the level of risk inherent in the design;

There is no substantial risk of concern.

9. Strength of the Scientific Team supporting the Study;

See #6 above.

10. Level of support guaranteed by the Institutes;

No comments of significance.

11. Budgeted cost of the Study;

While the costs are very modest, it is unclear what exactly the budgeted cost will support. Labor is apparently provided in-kind by SAO, with the budgeted costs designated as being for “materials and services.” The proposal does not clarify what materials & services are required for this study, which is primary a literature study and conceptual design study.

  • Reviewer 11
Grade: 4.5

Title: Enhancing Band 10 Aperture Efficiency: An Active Mirror Study - 546 - Kumara

1. Alignment with NA ALMA Partnership strategic goals;

The proposed study's deliverables, focused on doubling the efficiency at Band 10 by improving the overall surface accuracy of the ALMA antennas to 15 micron (i.e., an additional thermal and gravitational correction) are for sure compelling. However, relative to other proposals before the panel, the proposed study commands less urgency.

2. Strength of the scientific case for the proposed ALMA upgrade concept; Comment on the relevance to the ALMA 2030 development documents.

The proposed study is reasonably in line with ALMA 2030 recommendation #2, i.e. "Larger Bandwidths and better sensitivity".

3. Quality of the upgrade conceptual design;

The deliverable of the project is a conceptual design in itself! I think a conceptual design for the preferred active surface implementation will be clearly valuable.

4. Readiness for production in the context of the ALMA Development Plan (the aim is to support a range of upgrades including both those which can be implemented rapidly and those requiring longer-term research and development);

The proposed study would explore solutions that might represent an extremely substantial modification of the ALMA Front-end design, including (e.g.) a deformable sub-reflector, "magic box" correcting optics system, and flat active mirror at the image of the primary. While it would certainly be nice to see this study's deliverables, e.g. conceptual designs for all three approaches, along with a comparison of their advantages and disadvantages, the proposed study seems like a catalyst for proposals that will likely be extremely expensive, and probably less urgent relative to other needs of the observatory.

5. Strength of the consortium organization (if applicable);

The team consists of SMA experts from SAO, clearly suited to the proposed task.

6. Qualifications of the key personnel of the Study;

See above.

7. Technical expertise, past experience (also in series production, if relevant) and technical facilities in the Institutes taking part in the Study;

See above.

8. Assessment of the level of risk inherent in the design;

The proposed study is reasonably simple and cheap, and is therefore associated with low levels of risk. However, the projects deliverables seem less compelling relative to other proposals before tha panel.

9. Strength of the Scientific Team supporting the Study;

See Section 5 above.

10. Level of support guaranteed by the Institutes;

See Section 5 above.

11. Budgeted cost of the Study;

Low. $46K for the whole project, whose deliverables include a summary of the state of the art from literature, an analysis of the three concepts, and preliminary design for the preferred concept.

-- AlWootten - 2017-08-02
Topic revision: r1 - 2017-08-02, AlWootten
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