AMiBA Engineering Telecon Minutes

24, Jan. 2002

Chair: B. Martin (USA)

Participants: J. Peterson (USA), M.Kesteven, W. Wilson, R. Gough (Sydney)

K.Y. Lo, H. Wang, T.D. Chiueh, M.T. Chen, H.C. Lu, C.T. Li, Y.J. Hwang,

H.M. Jiang, W.Ho, P. Shaw (Taipei)

Summary:

MMIC:

1. Huei is working on TRW model together with TRW engineer since this week, and in parallel Huei has asked for Russell's help in testing DCI curve. Russell will finish that test and send test file to Huei shortly.

2. Russell also helps Huei to measure the noise figure of the pre-stage LNA, he will start measurement by next week.

3.The collaboration between ASIAA and JPL for packaging and testing LNA for AMiBA at JPL is necessary to be approved by NASA HQ, and now Charles Lawrence & Todd Gaier are working on that. But as a backup plan, Charles & Todd suggested that JPL could build and test the first batch of amplifiers for the seven-element  intermediate step, for delivery this summer as needed.   During that time we would obtain the needed approval at NASA HQ for Taiwanese participation in the testing of amplifiers for the full AMiBA. Fred & Huei will follow up to set up a telecon to discuss this issue further with Charles and Todd.

Correlator:

1. The first unit of 16 lag correlator, amplifiers and noise figure measurement data are arrived at AT from Jeff this week. Jeff has prepared a" First report on Meridian Microwave Lag Correlator" and circulated to people to read. Jeff said the test result at low frequency seems ok but at the response at high frequency is not so good, and he will finish all tests he can do on the second unit and wrap up a complete test report shortly. Warwick will read Jeff's report and start testing the first unit this week.

2. Fred concludes the general issue of correlator that Warwick should finish testing and integrate the whole things on prototype correlator to make sure we have something can be used for prototype.

And after that done, we really need to seat down and have some discussions what to do next exactly.

We need to properly improve the current design as Jeff reported on, and very important factor is how to do it in a way to make it a lot cheaper, because the current cost is not affordable.

Fred intends to have a serial telecons at some points and could sort out a time frame

when people gather in Hawaii to help assemble correlator, and will take sometime to go over issues in great detail. But discussion of course beforehand for preparing that meeting, and we do need to come to an conclude plan. We are in the process of hiring Derek Kubo to work on this project, and we have a post doctorial also preparing to join in. At least we have some additional delegated manpower to work on this project and perhaps supervised by Warwick and contribution by Jeff to get the correlator we need.

We need to demonstrate what we have done as much as possible to the reviewers of the coming site

visit of I, Feb.

Prototype mount:

Production is on going and will be completed and shipped to Hawaii on schedule.

Vertex mount:

We had an draft performance specs, and we had a internal meeting to discuss two days ago, and generate some action items and questions to Vertex. Bob has scheduled a meeting with Vertex to discuss those questions sent to them.

Receiver:

The miss-alignment problem of receiver has been solved and cold test is moving on. We have made some pictures and 3D figures of receiver and parts in every production stage. The lab will assemble those two prototype as complete as possible so that we could have a nice lab tour for site visitors.

30cm dishes:

The reworking on the secondary mirrors have been done, and re-measuring is still on going.

Bob will ship one dish to Taipei and keep the other one in Tucson for further more checks.

Site:

No progress on site issue so far, Bob will keep on pushing MLO to move.

Control software:

Honming has tested the control software for receiver, he will tell Mike about what kind of problems he had by email. Honming has generated a annual report, he will send to Mike to review as well.

Optical telescope:

Bob and Mike had a phone discussion last week, Mike will follow up to write up a specification, and then circulate to everyone to read and to comment.

Work plan 2002:

Our goal is remained the same without change, but our internal goal is to build a seven-elements in interim stage in order to expedite the polarization experiments by early 2004. So we should focus on this interim goal to generate the work plan for this year accordingly. In the mean time, science team will keep on working with the data simulation of pipeline to figure out what optimal size and how many elements we need to build and how to meet science goal as well. Of course, cost is one of the crucial impact to the final plan, and we shall have a better idea when prototyping

is going through.

Action items:

1. Paul/      Paul will ask Philippe to take pictures on the production status of prototype mount so that we could show the reviewers about what we have done on the prototype mount.

2.All/         Thanks for all your inputs for site visit, we have posted all inputs at AMiBA site. for those who haven't submitted yet, please do it ASAP. For details, please read the AMiBA home page :

http://www.asiaa.sinica.edu.tw/amiba/priv/Input%20Docu%20List.html

As for the work plan 2002, please write up and send to Paul ASAP, so that we could go over to see whether those work plans are workable or not.

3. Bob/          Bob will follow up pushing MLO to figure out the leasing agreement for site.

Next meeting:  Thursday, 31, Jan. at 8:30 Taipei Time.