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Program Advisory Committee (PAC)

PAC 15 Call for Proposals

October 22, 1998

Dear Jefferson Lab User,

During the week of January 25-29, the Jefferson Laboratory Program Advisory Committee (PAC15) will consider new proposals, updates, and letters-of-intent. PAC15 will also review the schedule for experiments in the three Halls. The JLab Technical Advisory Committee (TAC) will make comments on the technical viability of the proposals and provide these comments to the spokespersons and the PAC prior to the meeting. As always, proposals will be judged on the quality of the physics, technical feasibility, and the ability of the group to carry out the proposed measurements.

The backlog of approved experiments at Jefferson Lab is large -- between six and seven years for our present schedule with our present overall operating efficiency (~50%). To keep the backlog in equilibrium, the PAC will receive guidance for Halls A and B that no more than an equilibrium level of beam time be recommended for approval (three months of running per hall or 1-1/2 months of 100% efficient operation). This guidance will not be so rigid as to preclude PAC consideration and recommendation of important new experiments and/or programs that cannot be accommodated within the nominal beam time limits, but any such exceptions will have to present a compelling scientific case. In the case of Hall C, the jeopardy process has begun so the rules outlined in the section below will be followed.

We continue to work hard to improve the accelerator and hall operating availabilities in order to provide more useful beamtime each year. This is one of the primary focuses of both the Accelerator Operations group and the Hall groups. We have requested incremental funding from DOE in support of this effort, and we have also asked DOE for further additional funding so that we can deliver more physics each year. Discussions on these issues are ongoing.


The laboratory has a three-year Jeopardy Rule that will provide a second mechanism for keeping the backlog roughly constant. Jeopardy begins three years after a hall has begun taking data or three years after the proposal was approved, whichever is later. PAC15 will review the first set of the Hall C experiments (a total of six) that fall under the Jeopardy Rule. The spokespersons of these experiments are being notified directly about the fact that their experiments will be reviewed under jeopardy. The jeopardy process will begin with the summer 2000 PAC in Hall A and with the winter 2000 PAC in Hall B.

The Jeopardy policy is intended to ensure that the ratings of all approved experiments continue to accurately reflect their scientific priority. It recognizes the fact that the scientific world does not stand still: theoretical developments and experiments elsewhere can affect the scientific interest in experiments here, and therefore their priority. It reinforces our goal of always identifying and running the best possible science program. Jeopardy also provides a fair and equitable mechanism to reduce the backlog of approved experiments to about three years, as recommended by the Users Group Board of Directors, the PAC, and the laboratory's Science and Technology Review Committee as optimum. To this end, PAC15 will be asked to limit the total beamtime it awards in Hall C (for both new and jeopardy proposals) to an amount that reduces the Hall C backlog by roughly one-third of its current excess above the target value of three years -- i.e. in Hall C we will ask PAC15 to reduce the backlog from its current value of 5 to 6 years to a new value of 4 to 5 years.

The PAC will consider both new proposals and resubmitted "jeopardy" proposals on an equal footing. This will clearly have the effect of "raising the bar" for experiment approval.


New Proposals

New proposals requiring beam energies up to 6 GeV will be reviewed by PAC15.

Experiments with Similar Physics Goals

On your proposal cover sheet indicate any existing approved, conditionally approved, or deferred experiments that have physics goals similar to those in your proposal. In the text of your proposal, compare and contrast your proposal with respect to these proposals and experiments already considered or under consideration by previous PACs. Note that both one-page summaries and the full text for most proposals is available on-line at You may also contact User Liaison (see below) for copies of proposals.

The spokespersons for the experiments and proposals you have listed on your proposal cover sheet will receive copies of your proposal prior to the PAC meeting. They will be allowed to submit written comments that will then be passed on to the PAC with a copy provided to you. If you fail to identify a previously approved proposal with similar physics goals, the spokesperson for the previously approved proposal may request that final approval of your proposal be contingent on review by a subsequent PAC of the issues they want raised. If laboratory management agrees that the request has merit, the final approval of your proposal will be deferred until the following PAC has reviewed the situation.

Experiment Summaries

A summary of all approved and conditionally approved experiments can be found online at: PAC reports can be found online at:

Beam Time

The beam time request should be provided in some detail. Do not request any contingency time as the scheduling process includes this time. The beam requirements and time request should include all of the time for the following activities


If your collaboration has an approved experiment, a conditionally approved experiment, or a deferred proposal and you would like to modify the physics goals, significantly change your running conditions, receive reconsideration of your scientific rating, or achieve full approval for a conditionally approved or deferred experiment, please submit an update.

Note: The PAC may or may not choose to hear an oral presentation for updates depending on the scope of the proposed changes.

Deferred Experiments

Deferred experiments must be updated within one year or they will be removed from future consideration.

Rejected Proposals

A proposal based on a previously rejected proposal is considered a 'new' proposal. Further, this 'new' proposal must include substantive changes that fully address the issues raised by the PAC that rejected it for it to be considered by the new PAC.


Letters-of-intent may be submitted to solicit the evaluation by the PAC of a new line of research before investing the large effort required to prepare a full proposal. In general, the letters-of-intent will involve either a major new experimental apparatus or extension of present beam properties.

Letters-of-intent will be made public after receiving PAC appraisal in the same manner as full proposals. This means that the research program contained in them would enter the public domain; therefore, the letters-of-intent mechanism cannot be viewed as a means of "staking out territory." Rather, it provides experimenters with feedback at an early stage on the PAC's views on the scientific and technical merit of an idea that the experimenters intend to develop into a full proposal.

Due Date: New Proposals, Updates, and Letters-of-Intent

Proposals, Updates, and Letters-of-Intent are due to User Liaison by close of business Thursday, December 17, 1998.

Jefferson Lab
User Liaison Office, MS 12B
12000 Jefferson Avenue
Newport News, Virginia


All submissions can be mailed or submitted electronically. Faxes will not be accepted. If you would like to experiment with submitting your proposal electronically in either HTML, PDF or postscript format, please contact User Liaison by December 11, 1998. We will test our ability to locally acquire and print a draft of your proposal. If successful, you may submit your proposal electronically by 3:00 p.m. on the due date stated above.

All proposals and updates to be considered by PAC15 must also include a completed:

These sheets are available at or via anonymous ftp at in pub/pac/attachments in PDF and postscript formats.

Procedures for Experiments

Procedures for experiments are provided at procedures include the submission and re-submission of proposals, the PAC's scientific ratings and recommendations of Approval, Conditional Approval, Deferral or Rejection, the Directors award of beam-time, the experiment preparation and scheduling processes, the associated Environment, Health and Safety reviews, the running of the experiments, the allocation of computational resources, and the publication of results including presentations at conferences.

Reference Material Hard Copies

If you would like any of the materials on the Web sent to you in hardcopy, please contact User Liaison via phone (757-269-7586), fax (757-269-7003) or e-mail ( This call can also be found online at

I look forward to seeing you at Jefferson Lab.


Karen Hokansson
User Liaison Manager