TRIUMF: Guide for experimenters

From Delivery Wiki
Jump to navigation Jump to search

The purpose of this site is to provide all the necessary information to allow a User to propose, plan, and run an experiment at the ISAC Facility of TRIUMF. It has been created by the Beam Delivery group of the Accelerator Division [Link? -- ACM] and should be used in conjunction with the Experimental Program site managed by the Science Division(email?).

This wiki is a work in progress and will be updated frequently. Please forward all comments, queries, and suggestions to Mike Trinczek(email).


Guide for experimenters at TRIUMF

Mounting an experiment at TRIUMF

Before an experiment can be mounted at TRIUMF, it must be evaluated, approved and granted beam time. TRIUMF’s Science Division requires that detailed information regarding the preparation and running of experiments be provided as part of formal experimental proposal. TRIUMF has three Experimental Evaluation Committees (EEC) to evaluate such proposals in the fields of Subatomic Physics (SAPEEC), Molecular and Materials Science (MMSEEC), and Life Sciences (LSPEC). Calls for proposals are typically issued twice a year for consideration at EEC meetings in mid-summer and early December.

Beginning with the Subatomic Physics EEC meeting in December 2007, a two-stage approval process will be used.

Stage 1: Physics approval

The EEC will consider experiments on the basis of scientific merit. Those experiments deemed to be of merit will be granted Stage 1 approval to run and assigned a scientific priority based on their importance as judged by the EEC.

Stage 2: Beam allocation

At the time of proposal, TRIUMF staff will judge experiments on the basis of technical feasibility – beam availability, equipment availability, and safety – and report their findings to the EEC. If an experiment is deemed to be feasible over a two-year time scale, it may be granted Stage 2 approval and allocated beam time. This allocation would be valid for the same two-year period over which the feasibility of the experiment was considered. Stage 2 approval is not automatic. As the total amount of beam time available to be allocated is limited, it may be withheld on the basis of scientific priority.

For many experiments, and especially those using existing experimental facilities, Stage 1 and Stage 2 approval could be granted at the same EEC meeting. Experiments with both Stage 1 physics approval and a Stage 2 beam allocation are considered “active.” Those with Stage 1 approval but lacking the Stage 2 beam allocation remain on record, but are considered “pending” rather than active. In such a case, the spokesperson would be expected either to revise his/her proposal appropriately and seek Stage 2 approval at a subsequent EEC meeting or to abandon the experiment. Experiments for which Stage 2 approval is not sought in a timely fashion, or which have been granted Stage 2 approval but for which beam time is not sought within a two-year period, may be deemed “inactive” and, ultimately, struck from the record.

Proposing an experiment

Proposals to the EEC are submitted electronically. A User ID must be obtained from TRIUMF’s Science Division to use the web-based submission system. Web-based forms are used to submit overview information and certain technical details; however, a detailed statement of the proposed research is still required. A template and uploading instructions are available on the EEC submission web site. For experiments using existing facilities, a description of the scientific aspects of the experiment may be sufficient. For those using new facilities or new experimental setups at existing facilities, detailed technical information will be required. Additional information for experimenters preparing proposals, including a list of facilities and services coordinators, is available below.

Once a proposal is submitted, usually several weeks in advance of the EEC meeting, it is forwarded to the EEC members and TRIUMF staff for review. In general, the technical feasibility of a proposal will be reviewed prior to the EEC meeting so that the review results are available at the time of the meeting. TRIUMF staff may contact the spokesperson or a designate for additional information during this time. Any information that can be provided will aid the review process and increase the likelihood of an experiment being deemed feasible.

At the time of the EEC meeting, the spokesperson or a designate will be expected to present a (typically) 15—20 minute talk on the scientific and technical aspects of the proposal and field any questions that may arise. This will be scheduled in advance and may be carried out remotely, if necessary. This is a spokesperson’s last opportunity to address any concerns about scientific merit or feasibility before the EEC renders its decision.

Requesting beam time

Unlike many labs, TRIUMF does not schedule experiments on an ongoing basis. Instead, several months’ worth of experiments, spanning a single running period, are scheduled at one time. There are typically two running periods each year, one from April through early September and a second from late September through December. A call for requests for beam time is generally issued 8—10 weeks prior to the start of a running period.

Like proposals, requests for beam time are submitted electronically. Starting with the April 2008 running period, experiments will be reviewed for technical readiness prior to being scheduled. This is not the same as feasibility. Where the review by TRIUMF staff prior to EEC Stage 2 approval focuses on the feasibility of an experiment on the two-year time scale of an EEC beam allocation, this readiness review considers only the impending running period. If an experiment is judged to be in a sufficient state of readiness to use beam time effectively, it may be scheduled to run. As with Stage 2 approval, scheduling is not automatic. Because of the limited number of shifts available during each running period, it is not always possible to accommodate every experiment for which beam time is requested. While the scientific priorities set by the EEC serve as a guide, final scheduling decisions may depend on other factors such as target or equipment availability.

Safety approval is required before an experiment can take beam. To streamline the submission process, safety reports will be sought as part of the request for beam time. These reports will be reviewed by TRIUMF staff. In many cases, the written report will be sufficient for review and approval; however, in certain cases it may be necessary to schedule a formal review with the spokesperson or a designate. Having safety reports in hand prior to scheduling helps TRIUMF ensure that experiments can be carried out in a timely fashion.

Running an experiment

Experimenters should prepare to be on site in advance of their experiment. If it involves a standing setup at an existing facility, a few days may be sufficient to ensure devices are tested and calibrated prior to running. For new setups or facilities, several weeks’ presence may be required. This should be arranged with the facility coordinator and any local collaborators.

Approximately two weeks prior to an experiment, representatives from TRIUMF’s Beam Delivery Group will meet with the spokesperson and/or designates to discuss beam requirements and assist with detailed run planning. Despite the lab’s best efforts, downtime – for maintenance, target changes, etc. – that was not foreseen during the scheduling process may be required during the course of a run. The Group will identify potential interruptions so that the experimenters can plan accordingly. A liaison will also be assigned at this point to assist the spokesperson and designates.

In the days before an experiment, a Beam Properties Request (BPR) will be required by Operations. This is essentially the license to run – without a BPR, no beam will be delivered to an experiment. It should be noted that Safety approval is required at this point. The BPR is required 24 hours in advance. Links to blank forms are available below.

During the run, the spokesperson (or a designate) is expected to serve as the main point of contact for the experiment. The beam liaison will serve as the primary contact for Operations and the lab. It is important that there be a single, well-defined line of communication between the experiment and TRIUMF. Off-hours, direct communication between the spokesperson and Operations is encouraged; however, the liaison will still attempt to stay abreast of the experiment’s progress and intervene as necessary.

Once the experiment is complete, it is the users’ responsibility to ensure all data are properly backed up. Experiments should be dismounted as promptly as possible to allow preparations for following experiments to begin. Experimenters should prepare to remain on site while this work is done. For standing setups, a few days may be sufficient for final calibrations and background checks. If equipment is to be torn down (or torn down and prepared for shipping), several weeks may be required. As with mounting an experiment, the dismounting of equipment or electronics should be arranged with the facility coordinator and any local collaborators.

TRIUMF Facilities and Support Groups

Support Groups

Meson Hall

ISAC

  • Radioactive ion beams - Pierre Bricault, Marik Dombsky
  • Accelerators - Bob Laxdal, Marco Marchetto
  • Beam liaison - Colin Morton


The ISAC Facility at TRIUMF. Click for larger view.


The ISAC Facility at TRIUMF has two experimental halls with a diverse range of Experimental Facilities and Research Groups. Each facility has a TRIUMF-based Coordinator who is responsible for the safe operation of the facility and will act as a User and Visitor liaison. Interested scientists should contact the appropriate Coordinator from the lists below to obtain more information.

ISAC Low-Energy Experimental Facilities:

  • Collection Station - Coordinator:
  • TRINAT - Coordinator: John Behr
  • 8π - Coordinator: Gordon Ball
  • GPS1, GPS2, GPS3 General Purpose Stations - Coordinator: Gordon Ball
  • Laser Spectroscopy - Coordinator: Matt Pearson
  • Polarizer - Coordinator: Phil Levy
  • βNMR and βNQR - Coordinator: Gerald Morris
  • Osaka - Coordinator:
  • TITAN - Coordinator: Jens Dilling

ISAC-I (Accelerated) Experimental Facilities:

  • DRAGON - Coordinator: Chris Ruiz
  • TUDA - Coordinator: Pat Walden
  • HEBT-GPS General Purpose Station - Coordinator: Dave Ottewell

ISAC-II Experimental Facilities:

  • HERACLES (Under construction) - Coordinator: Dave Ottewell
  • SEBT-GPS General Purpose Station - Coordinator: Dave Ottewell
  • TIGRESS - Coordinator: Greg Hackman
  • EMMA (Under construction) - Coordinator: Barry Davids


ISAC Accelerator Specifications

The ISAC accelerators offer different time structures, as listed in the following table:


ISAC Accelerator Time Structure
Frequency (MHz) Period (ns) RFQ Transmission (%) Chopped Comments
35.36 28.3 25 No
35.36 28.3 75 No Two satellite peaks [Huh? -- ACM]
11.78 84.8 73 Yes
5.89 169.7 37.5 Yes


The ISAC-I Drift Tube Linac (DTL) can accelerate ions to the energies shown in the following table:


ISAC-I Range of Energy
A/Q Minimum Energy (MeV/u) Maximum Energy (MeV/u)
2 0.15 1.90
3 0.15 1.79
4 0.15 1.74
5 0.15 1.64
6 0.15 1.53


The ISAC II superconducting linac is capable of accelerating ions to the energies shown in the following table. Please note that the maximum energy is currently limited by TRIUMF's operating license to 5 MeV/u.


ISAC-II Range of Energy
A/Q Minimum Energy (MeV/u) Maximum Energy (MeV/u)
2 1.5 10.5 5.0
3 1.5 9.0 5.0
4 1.5 6.8 5.0
5 1.5 6.0 5.0
6 1.5 5.0


Specs
Beam standard transverse dimensions (at a focal point) 2 mm [FWHM? RMS? -- ACM]
Transverse emittance 2 π mm mrad
Longitudinal emittance 1.5 keV/u ns (ion dependent)
Longitudinal emittance 1.5 keV/u ns (ion dependent)
Energy spread (FWHM) with no buncher <0.4%
Energy spread (FWHM) with buncher 0.1%
Time spread (FWHM) with buncher 1 ns


Add a calculator to show the interplay between Energy Spread and Time Spread?

Tuning Time Estimates

To help Users better plan their experiments, a list of typical time estimates for established tuning procedures is shown below. These estimates should be used by the User to budget the necessary overhead for experimental start-up, energy changes, species changes...

[Ask Bob about species changes! Ask Bob about start-up!]

In addition, interruptions to beam delivery may occur. Some of these interruptions, such as those due to regular maintenance or proton therapy, are known at the time the Beam Schedule is prepared and scheduled accordingly. Others, such as work in the ISAC Target Hall, may not be known at the time of scheduling but are known on a time scale of weeks in advance. The Beam Delivery group will try to meet with the experimental spokesperson(s) prior to the beginning of an experiment to confirm what is required from a beam delivery standpoint and to assist with the preparation of a detailed running plan, taking into account these known, but not scheduled, interruptions. At ISAC, this planning may help a User decide the optimum time for an energy change or a species switch. Totally unplanned interruptions, such as those due to mechanical failures, are unavoidable. Because TRIUMF is a user facility, catering to many external experimenters, it is generally not possible to adjust the beam schedule in response to such interruptions.


Tuning Time Estimates
Procedure Time
General tuning:
  • Proton BL2A
  • Stable beam in Pre-Accelerator section
  • RIB in Pre-Accelerator section
 
  • 1 hour
  • 12 hours
  • 4 hours
ISAC-I LINAC tuning to full energy (OLIS to User) 12 hours
ISAC-I energy change:
  • Change to pilot beam
  • Switch energy and optimize
  • Change to RIB and optimize
 
  • 0.5 hours
  • 1 hour/tank [Define "tank" -- ACM]
  • 1 hour
ISAC-II LINAC tuning (from scratch) 4 hours
ISAC-II energy change:
  • Change to pilot beam
  • Switch energy and optimize
  • Change to RIB and optimize
 
  • 0.5 hours
  • 1 hour/cryomodule
  • 0.5 hours
Checking the tune:
  • Cyclotron (minimize spills)
  • Proton BL2A
  • ISAC Pre-Accelerator section
  • ISAC Accelerator section
 
  • 4 hours
  • 1 hour
  • 2 hours
  • 2 hours
Maintenance Day (typical):
  • Cyclotron off
  • Cyclotron tuning
  • ISAC Tuning
 
  • 12 hours
  • 2 hours
  • 2 hours
Proton Therapy (typical) 5 hours


ISAC Yield Measurements Database

The ISAC Yield Measurements database should be consulted for the measured intensities of available species.

All yields are measured at the ISAC Yield Station unless otherwise noted. As such, the intensity delivered to any given experimental facility will depend upon the beam transport efficiency and the stripping efficiency, if needed. Delivered yields will be lower, especially for post-accelerated beams.

Below is a table giving the approximate transmission to different experimental facility areas for given conditions. The measured yield value should be multiplied by this factor to obtain an approximate value of what intensity may be expected at an experiment facility.

Need the numbers for different areas and conditions (stripping, chopping, ...)

Do we mention that intensities drop over time (i.e. these should not be time-averaged expectations)?


Beam Transmission
Destination Transmission (%)
Low-energy 85
ISAC-I 25
ISAC-II 25


List of Forms

Need to get the official new EEC approval process!


Temporary links to required forms...

Safety Approval of Experiments at TRIUMF

Beam-Time Requests

Beam Properties Request Form (PDF)

TRIUMF Administration - Forms and Documents Repository


Describe Colin's function here or in preamble?? [How about another link to a Beam Delivery group page, here or in the next section, where we can describe all of our functions? -- ACM]

Useful Links

TSOP-07 - Approval of Experiments at TRIUMF

Science Division wiki

TRIUMF Experiments database

Beam Schedule

TRIUMF Safety homepage

Visitors info needed - Josie?

Temp link to TRIUMF Colours