Proposal Review Process
A total of 1836 proposals were submitted in response to the ALMA Cycle 6 Call for Proposals. The proposals were reviewed during a meeting in Tokyo (Japan) on 18-23 June 2018. The review committee consisted of 146 Science Assessors grouped into 18 ALMA Review Panels (ARP) that were distributed across five scientific categories: 1. Cosmology and the high redshift universe (4 panels) 2. Galaxies and galactic nuclei (4 panels) 3. ISM, star formation and astrochemistry (4 panels) 4. Circumstellar disks, exoplanets and the solar system (4 panels) 5. Stellar evolution and the Sun (2 panels). The Review Panels in Categories 1-4 contained eight Science Assessors each, while the Panels in Category 5 contained nine members each. Science Assessors were selected on the basis of scientific specialization while having a regional affiliation that closely matched the nominal ALMA regional shares  of  observing  time.  The full list of Science Assessors is provided in the Appendix. The 18 Panel Chairs served on the ALMA Proposal Review Committee (APRC) together with the APRC Chair, Masao Saito. The Review Panels conducted the initial scientific reviews and recommended which Large Proposals should be further discussed by the APRC. The APRC conducted the final review to recommend which Large Programs should be scheduled. The Joint ALMA Observatory (JAO) created an observing queue and assigned a priority grade to each proposal after considering the scientific rank determined from the review process, the share of observing time for each region, and proposal pressure for the various configurations and right ascension. Priority Grade A was assigned to the top ranked proposals up to a cumulative sum of ~1333 h of requested 12-m Array observing time. Grade B was assigned to high ranked proposals to fill the remaining time. Grade C was assigned to proposals that oversubscribed the time in a configuration by approximately 50%.
Proposal statistics
Of the 1836 proposals submitted, 100 received the highest priority of Grade A, 269 received Grade B, and 292 received Grade C. The Grade A and B proposals requested an estimated 3840 h of execution time on the 12-m Array. Together with the estimated 180 h of Cycle 4 Grade A proposals that will be carried forward to Cycle 6, this constitutes the 4000 h of 12-m Array time expected to be available for successful executions in Cycle 6. The titles, investigators, and abstracts of the Grade A and B projects are available from the ALMA Science Portal. Tables 1 and 2 list the number and requested time for proposals grouped by region and science category, respectively. Table 3 lists the number of Grade A and B projects for different proposal types. Various metrics of the proposal data are presented in the figures. Eighteen Large Proposals were submitted in Cycle 6. As recommended by the APRC, the following four Large Programs were scheduled : 1. ALMA Lensing Cluster Survey (2018.1.00035.L) PI: Kotaro Kohno (EA); coPIs: Franz Bauer (CL), Marc Postman (NA), Keiichi Umetsu (EA), Jean-Paul Kneib (EU), Masamune Oguri (EA), Eiichi Egami (NA), Johan Richard (EU), Masami Ouchi (EA), and Dan Coe (NA) 2.   ATOMIUM: ALMA Tracing the Origins of Molecules in dUst-forming oxygen-rich M-type stars (2018.1.00659.L) PI: Leen Decin (EU); co-PI: Carl Gottlieb (NA) 3. The Chemistry of Planet Formation (2018.1.01055.L) PI: Karin Öberg (NA); coPIs: Edwin Bergin (NA), Catherine Walsh (EU), Yuri Aikawa (EA), and Viviana Guzman (CL) 4. Fifty AU STudy of the chemistry in the disk/envelope system of Solar-like protstars (FAUST) (2018.1.01205.L) PI: Satoshi Yamamoto (EA); co-PIs: Cecilia Ceccarelli (EU), Claire Chandler (NA), Claudio Codella (EU), and Nami Sakai (EA) Collectively these four Large Programs were assigned 446 h on the 12-m Array and 46 hours on the 7-m Array.
Figure 8. Regional distribution of the Cycle 6 APRC and ARP members
Appendix: Cycle 6 APRC and ARP members