Do not apply for any of the new instruments listed below for semester 95A.

Policy

Although there has not been any change in policy regarding the release of new instruments, it is probably best to restate it. Instruments will not be released to the user community until they are fully commissioned. This includes determining their performance under a variety of conditions, testing of observing modes and ensuring adequate calibration. For some complex instruments, and SCUBA is the prime example, to enable users to obtain astronomy at the earliest opportunity, the commissioning will be done in a phased way. Opportunity will be announced to the community during the commissioning period for short `taster' observations to be done in serviced mode by members of the commissioning team. This plan was approved by the JCMT Board and is set out in the July 1993 Newsletter, p17.

One aspect of the above which may not be immediately appreciated by users is that unless the commissioning time occurs in clear weather, the full commissioning cannot be completed. This will further delay the release of the instrument. I am not prepared to release an instrument for which we cannot accept responsibility for the quality of the data and/or for which we are still modifying aspects of the instrument or the operating software. The weather factor is clearly more critical for the higher frequency instruments. Therefore I intend to request of the ITAC a block of time for commissioning of new instruments for semester 95A, to be flexibly scheduled in order that the receivers can be fully commissioned and released to the community as soon as possible. This is not only a sensible practice in general but is also essential for RxB3 and RxW as there is now a critical phasing of old/new instruments in the receiver cabin. Although this may cause some short-term frustrations for the users, I am convinced that the long-term gains are completely justified. The articles on calibrations in this Newsletter show the concern which we feel for our current understanding of the instrument suite at the JCMT and this is one of the major thrusts of the Science Group at the current time.

By the time of the ITAC meeting, we will be in a much better position to assess the precise delivery dates. Users are informed of changes in the email server or WWW.

RxB3

This instrument is scheduled for delivery to the telescope in the spring of 1995. Therefore observers should expect to use it during the middle to end of the semester but should plan their programmes on the basis of RxB3i performance. Although we anticipate that the commissioning of RxB3 will be relatively straightforward and currently we do not anticipate delays to the release of RxB3 to the users, past experience suggests that things are never so straightforward in real life. Applicants for B-band programmes will either get RxB3i or RxB3 depending on how they are scheduled in the semester. The latter should be thought of as a bonus.

SCUBA

As most of the readers will be aware, SCUBA has suffered a delay in shipping to Hawaii and at the time of writing the delivery date is uncertain. This has caused the need for a `second round' of continuum proposals to be called for semester 94B. This was unfortunate and highlights the problems of trying to anticipate the delivery of new instruments when notification of availability, applications for time and scheduling of the telescope are so far in advance of actual delivery. Therefore, rather than apply the same process as for semester 94B, where UKT14 was only stated to be available for the first three months with the anticipation that SCUBA would then take over, I propose a different plan for 95A. Observers should apply for UKT14 on the usual basis. When SCUBA arrives and commissioning begins, then at some point there will be a general call to the astronomical community for SCUBA serviced proposals during the commissioning phase. This might include observations from any PATT proposals which have been `bumped' through commissioning of SCUBA. I leave the details of this aspect to the individual TAG's who might have different views as to how they wish to proceed.

RxW

This receiver, operating at C and D bands, is expected to arrive in Hilo in early summer 1995. This receiver will require a more extensive commissioning period than RxB3 and therefore it is appropriate to issue a call for proposals for serviced observations to be undertaken by the commissioning teams in the same manner as SCUBA. Therefore, no RxW proposals will be accepted for semester 95A. Observers should consult the information system, JCMT_INFO, WWW or email exploders for the announcement of opportunity for observations. Programmes requiring C-band will continue to use RxC2 until a time when it is displaced by the commissioning of RxW, at which point they may have their observations done in serviced mode by the commissioning team, (as for SCUBA) at the discretion of the national TAG. As noted in the policy section, the removal of C2 at the earliest point is to ensure that all the available C-band weather can be utilised effectively for the speediest commissioning RxW (at C and D) for the users. This may also cause some scheduled C-Band proposals to be `bumped' and again I look to the TAG's to indicate how they wish the commissioning C-band observations using RxW to be determined. An announcement will be made regarding D-band through the electronic news media.

Ian Robson,

Director JCMT