THE INTERNATIONAL ADVISORY COMMITTEE

ON THE J-PARC PROJECTREPORT 21-March 2007

Linac Beam on January 24, 2007

28

Meeting 5 -6 March 2007

Tokai, Japan

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CONTENTSEXECUTIVE SUMMARY

3RECOMMENDATIONS
Subsidiary Recommendations

6
7

GENERAL STATUS OF THE PROJECT

8

J-PARC CENTER ORGANISATION
Attainments 2006-2007
Proposals From the J-PARC Center
Structure of J-PARC
Structural Developments
Matters to be Addressed as Full Operation Approaches

8
9
9
10
11
11

ACCELERATOR STATUS
Main Ring Performance
RCS Performance With the 181 MeV LINAC
RF Cavities for the RCS and MR
Commissioning and Initial Operations Planning
Expectation Management

12
13
14
15
16
17

HADRON AND NEUTRINO EXPERIMENTS

18

COMPUTER NETWORKS AND REMOTE ACCESS

19

MATERIALS AND LIFE SCIENCES
Target System
Instruments
User Interface
MLF Muon Facility

20
20
20
21
22

NUCLEAR TRANSMUTATION

22

APPENDIX IAgenda for the 6th International Advisory Committee Meeting J-PARC

25

APPENDIX II
Committee Members

27

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EXECUTIVE SUMMARY
The International Advisory Committee (IAC) for the J-PARC joint projectof the Japanese Atomic Energy Agency (JAEA) and the High Energy
Accelerator Research Organisation (KEK) met between 5 and 6 March
2007 at JAEA, Tokai and toured the construction site of J-PARC.
The IAC had reports from the Accelerator Technical Advisory Committee(A-TAC), which met the previous week at Tokai and the Neutron
Technical Advisory Committee (N-TAC), which met at Tokai 20 to 22
November 2006. The present report is also informed by reports from
the Muon Science Experimental Facilities Advisory Committee(MUSAC) meeting at KEK 11-13 January 2007. The agenda of the IAC
meeting is attached as Appendix I and the membership at Appendix II.
The J-PARC Project has reached an important point in its development. The
efforts of KEK and JAEA to provide strong funding in 2006-2007 hasboosted morale and brought successful progress in the construction. We
note that the LINAC reached full energy on time (24 January 2007).
The 2006-2007 budget provisions and reports from construction
divisions have restored confidence that the 3GeV accelerator would
meet its first operational goal in 2008 and that six neutron and one
muon instrument will be ready for first beam. The IAC expressly
indicates that the performance reported, both from the point of view ofachieving targets and inventiveness in meeting technical challenges isof very high quality.
Establishment of the J-PARC Center was a positive step forward in 2006 forthe project. The IAC commends the KEK and JAEA for the devolutionof responsibility that has occurred. Operational structures aredeveloping and have the potential to meet the challenges of the fuller
operational phase as beam is delivered in 2008 - provided adequate
funding is allowed and program management steps are implemented.
Using the metaphor of our 2006 report we state that the achievementsof this "child" of KEK and JAEA is already something for the "parents"
to be proud of - but their continued commitment to it and in theoperational phase, is essential. We draw attention to matters related tothese points below.

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The IAC now strongly recommends that KEK and JAEA settle an
operational budget and budget profile for J-PARC into the years 20082012. The current high morale and the many pressing technicaldevelopments that will arise with operation need this. At our request the
Director has prepared an analysis of cost cutting measures in theoperational budget - so that systematic improvement of the accelerator
system and instruments can be done within the envelope of about 190
OYen per annum (estimated last year) at full operation after 2008.
Early operations inevitably reveal the need for adaptation of anaccelerator system- and this is particularly so with the reduced injector
energy.
The IAC has analysed the cost benefit of an early introduction of energy
recovery to 400 MeV in the LINAC. We conclude that design studies
for this Phase 1 project (removed to allow acceleration of the neutrino
project in 2004-2005) should be done at an early stage in theoperational phase with implementation in 2011. We consider that thisfits well with the scale up of the user program - as this program ramps
up with the increased performance of the accelerators during 20082011. The energy recovery will deliver the necessary power to theneutrino experiment and the neutron target for international preeminence from 2012.
With these parameters set, the IAC gave detailed consideration to models of
how the J-PARC Center might develop to the benefit of Japanese andworld science. We are convinced that the original concept of theJapanese Government - to bring together the cultures of KEK and
JAEA in this major center was right. The benefit to Japan of this moveis already obvious in the splendid cooperative work done for theconception and construction so far. Strong links to both "parents" must
be preserved to fulfill the initial vision of a world center.
The correct operational budget and operating characteristics of a great centerare now indispensable steps for the project. In the text below we
illustrate some " growing pains" which must be remedied. We also notesome centrifugal tendencies of the partners - faced with organisationalchanges and budgetary constraints of their own. Much is at stake andnow is the time for active participation of KEK, JAEA and the Japanese
Government to make key decisions so that coordination of the
programs arriving at J-PARC and the expectations of the users national

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and international will be met in a way that respects world's best practice.
These matters are illustrated below.
One aspect of the operation is the model under which J-PARC will function.
The IAC considered this in the light of the matters raised above. The
two extreme models are either a fully user oriented center - basically afacility, run in the best way for the external users or a research centerwith a distinguished core of in house scientists. Judged by ourexperience, neither of these is ideal. A model between them where "inhouse" excellence, as tested by access to the facilities in competition
with external users, has been proven elsewhere to be optimal. In thismodel "in house" staff have the dual responsibility of supporting theuser program and developing an individual research program. This
individual research program should be peer reviewed in the samemanner as the external user program.
The IAC thanks the J-PARC Director, Professor Nagamiya, and the project
team for the detailed information and discussion at the IAC meeting.
The distribution of papers before the meeting allowed key policy points
to be discussed early on. The IAC notes with approval the extent towhich its recommendations for IAC 2006 have been taken up by the
project team, the individual project leaders and the partnerorganisations.

In this report the principal recommendations have been numbered andbrought to the Executive Summary. There are a number of important
process recommendations – left un-numbered in the text.

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Recommendations

Recommendation 1: The IAC recommends that KEK, JAEA and theJapanese Government come together to make key decisions on
operational budget and organisation so that coordination of the
programs arriving at J-PARC and the expectations of the users,
national and international, will be met in a way that achieves world's
best practice.
Recommendation 2: The IAC urges both KEK and JAEA management
to consider mechanisms for transferring most operational
responsibilities and associated financial and personnel resources to the
J-PARC Center management as soon as possible.
Recommendation 3: The IAC again recommends that the 400 MeV
LINAC capability be restored as the immediate priority following
successful completion of the Phase I construction project and thetransition to initial operations. This should not be achieved at theexpense of initiating the fullest possible user program.
Recommendation 4: The IAC recommends that a commissioning teamleader be identified with responsibility and authority for coordinating
the commissioning of the entire J-PARC complex, including thetransition to operations. An integrated commissioning plan should be
developed containing the roadmap towards Phase I design goals anddefining technical, schedule, cost, and personnel requirements. The
integrated commissioning plan should be discussed with, and madeavailable to, the user community. The published plan should include
estimates of performance, anticipated reliabilities, and the time
allocation between users and accelerator physics.
Recommendation 5: The IAC recommends a model for operation where"in house" scientific staff have the dual responsibility of supporting theuser program and developing an individual research program. In
addition, some staff - scientists, engineers and technicians will be needed
to maintain and develop the facility

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Recommendation 6: The IAC urges the J-PARC Center to develop
plans for the strategic population of the Neutron and Muon Instrument
Suite, creating, as early as possible, a balanced portfolio to satisfy thelarge and dynamic Materials and Life Science Community in Japan.
Subsidiary Recommendations
Recommendation 7: The IAC agrees with the recommendations of
ATAC that a reassessment of operating scenarios be aligned with aperformance goal of 450 kW in the main ring based on the Phase I
configuration.
Recommendation 8: The IAC agrees with the recommendation of
ATAC that an improvement plan for the RCS collimation system beprepared to provide sufficient margin to cope with realistic operations
scenarios.
Recommendation 9: The IAC urges that the plan for involvement andengagement of KEK staff in accelerator operations, improvement andupgrades be formulated already at this stage.
Recommendation 10: We recommend, that the construction of the “DaiOmega” channel receive the highest priority of the phase II muon
projects. We recommend that the accelerator team continue to work on
reducing the 3GeV proton beam pulse width to 100 ns or less.

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GENERAL STATUS OF THE PROJECT
From the presentations and the tour of the accelerators the Committee hasformed a clear impression that J-PARC will become a world center of
excellence in the broad area of science set out in the original goals by thepartners JAEA and KEK. The right continuing support from the Japanese
government and the combined expertise of JAEA and KEK will produce thisand demonstrate the soundness of the Japanese Government's concept forthis joint program. The present success has been achieved by goodmanagement, the formation of the J-PARC Center and, particularly, by the
devotion and hard work of the teams at J-PARC. The very great attention todetail needed to achieve such a broad result is commended. Of course, there
are many things still to be done, problems to be solved and preparations to
be made as full operation is reached in 2008. The fact that the projectapproaches this target date with confidence is a major signal of merit.
The present report reinforces some of the policy and action points of ourprevious reports and is coherent with them. Detailed proposals from the JPARC Center have been considered and are responded to here. Advice isoffered on strategies for the optimum operation of the facilities to meet thestrong expectations of J-PARC growing in the user community.
J-PARC CENTER ORGANISATIONThe J-PARC Center is now a key feature for ensuring the timeliness andquality of all aspects of the project. Its establishment to manage a worldclass accelerator complex, as it enters its exploitation phase, is succeeding.
A structure has been agreed by the two funding partners, KEK and JAEA,
which should provide a managerial environment to develop J-PARC to its
full potential. The IAC congratulates KEK and JAEA management for theirvision in establishing the bases for an effective organisation in the difficultcontext of shrinking budget and future uncertainties in their own overall
programs. The vision of a strong international center at J-PARC with ascientific reach which will be enhanced beyond that provided by the sum of
the two investments by KEK and JAEA through the new partnership is fully
endorsed by the IAC which would like to offer the advice for the next steps.
Recommendation 1: The IAC recommends that KEK, JAEA and theJapanese Government come together to make key decisions on
operational budget and organisation so that coordination of the

-9-programs arriving at J-PARC and the expectations of the users,
national and international, will be met in a way that achieves world's
best practice.

Attainments 2006-2007
The achievement of 181MeV injection energy for the LINAC on the 24th ofJanuary 2007 was a milestone for the project. The team is to be commended
on reaching this goal in a timely and elegant way. Inspection of the LINAC
facility shows a spectacular example of Japanese science and technology. In
the same way, the presentations and our visits to the RCS, the Materials andLife Science Neutron Scattering and Target Areas, the presentations on theseareas as well as in the neutrino and nuclear physics area, the developments
around the 50GeV ring and the Hadron Physics Center all look to beachieving the same spectacular quality. We particularly comment on thedevelopments for the mercury target in the neutron production area.
Enormous ingenuity has been applied in the design as well as the execution
to its present state. Developments that will lead to improvements during theoperation phase and attainment of the final 1MW operation are commended
and must continue with careful input from the international N-TAC.
Coordination with the only other development of this kind at the Oak Ridge
National Laboratory, SNS, is also commended and is an illustration of thebest relationship between major scientific centers.
Proposals From the J-PARC CenterIn the course of the review, and from the documents presented to theCommittee, a number of issues for advice were raised by the J-PARC Center.
One issue concerned the improvement of communication between the JPARC Director and both JAEA and KEK. In this respect, the IAC welcomes
Professor Nagamiya's appointment to the J-PARC Core in JAEA and as amember of the Board of KEK. Another issue was the devolution of authority
to the Director to make third party contracts. This is another commendable
step taken by the partners, as is the agreement about no beam time fees foracademic use of the facility. This will be very important for drawing the best
people and the best science to J-PARC both nationally and internationally.
International scientific communities expect that both sides, KEK and JAEA,
will make every possible effort to realise J-PARC project to the full extent,
which they officially declared to commit themselves. For example, KEK is

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expected to make proper decisions in respect of the various projects theydecided to commit to in J-PARC at the outset. In this respect,
implementation of a solid administrative structure and associated functions,
including right to make budgetary proposal and personnel hiring, of J-PARC
Center is highly desirable with the help of KEK and JAEA.
At the level of the science program the IAC strongly supports the "single
doorway" entry of proposals via J-PARC Center. The arrangements for peerreview of proposals are developing satisfactorily and we have advocatedcontinued and strong connection to the user community who should beaware of developments in the facilitation structure J-PARC. These measuresare very important in the management of user expectations.
Structure of J-PARC
In our 2006 report (Recommendation 6) we made a preliminary
consideration of the way in which the J-PARC Center might operate withrespect to its national and international communities. Further considerationof this point arose at the IAC. We obviously reject the model of a "closed"
but excellent Center and the other extreme of a purely user-oriented facility
with a minimal sized group of scientists, engineers and technicians ensuring
facility development and expert operation of the various components. The
favored model of the IAC lies between these two for young scientists joining
the organisation. Their terms of employment should have the dual
specification of service to external users and development of their individual
scientific program. In this mode the scientific quality of J-PARC staff would
itself be tested by their having to make proposals for their experiments
through the program advisory committees' peer review process. It would ofcourse be open to the "in house" people to make joint proposals externally.
The IAC heard very interesting suggestions about the J-PARC "User Office"to develop and facilitate the external user program. In this respect electronic
communication to and from J-PARC (publicity, proposal review and userinternet access) need to be highly professional. For users, theiraccommodation and ease of access to the J-PARC site will be important. The
point was strongly made at the IAC meeting that one of the greatest benefits
that can come to Japan from the J-PARC Center will be the inflow of newscience and the scientific competition for access as proposals are peer
reviewed and refined.

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Structural Developments
As the capitalisation of Phase I projects is ending and the focus turns
towards the operation of the accelerator complex, the time is right for a bolddecision in transferring the operational responsibilities and associatedfinancial and personnel resources to the J-PARC Center management. This
would strengthen the position of the J-PARC center director allowing for an
at-arms length relationship with the two parent institutions KEK and JAEA
on operational matters while retaining a strong scientific oversight role. The
IAC understands that this is a major decision that will require a qualitativechange in the way both KEK and JAEA operate but feels that the long term
benefit of such an arrangement will offer the best chance for the success of
J-PARC as a joint project of the two institutions.
Matters to be Addressed As Full Operation Approaches
The IAC has been made aware of coordination gaps developing between
areas of responsibility such as the different accelerator systems. Althoughsuch deficiencies are not unusual in projects of the scope of J-PARC, theresolution of them in the context of continued split operational
responsibilities between KEK and JAEA makes for time consuming
negotiations which affect the effectiveness of the decision making process.
As an example of such coordination gaps, the situation of the ambitious
neutrino project. Establishing areas of responsibility amongst a large
multinational partnership, which has grown to cover 65 institutions in 12
countries, has been exacerbated by a lack of focal point in J-PARC
management regarding the infrastructure support to be provided by the hostinstitutions.
In addition, not only will the J-PARC accelerator have to handle the mostintense proton beams in the world safely but also, an interface with major
equipment elsewhere will have to be managed in the operation phase as wellas the construction phase, electronically and internationally. This electronic
management will have to be very transparent and powerful and the quality
equivalent to that at other major international centers such as CERN.
A third area of possible concern is in the management of the commissioning
efforts for the accelerators - mentioned in the accelerator report, which relieson the partition of responsibilities in place during the construction phase.
That effort would benefit from a unified organisation of the accelerator
support groups.
Recommendation 2: The IAC urges both KEK and JAEA management
to consider mechanisms for transferring most operational

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responsibilities and associated financial and personnel resources to the
J-PARC Center management as soon as possible.
The above points indicate a strong need at this time for technical and project
coordination across the site. At the moment, the Director has not yet beenable to appoint a technical coordinator in response to our Recommendation 3of 2006 but has created the Director's group to manage this. The IAC accepts
this measure provisionally, but from its own experience suggests that a site
wide process headed by someone to whom the Director could delegate
responsibility for ensuring that site-wide infrastructure developments could
be addressed, be appointed.
ACCELERATOR STATUS
The Accelerator Technical Advisory Committee (ATAC) reviewed thestatus of the accelerator construction project over the period March 1-3,
2007. The ATAC delivered its report at the IAC meeting.
The construction project has made considerable progress over the prior year
and is now nearing completion both in terms of civil construction andaccelerator component fabrication. Major achievements over the last year
include successful acceleration of beam in the LINAC to the full design
energy of 181 MeV in January, 2007, and the development of a viablestrategy for resolving issues with the RCS and MR rf systems which were
the dominant challenge of a year ago. Congratulations are due to the JPARC accelerator team on both of these significant accomplishments. RCS
beam commissioning is scheduled to start in September of this year with MR
beam commissioning following in May 2008. This schedule is unchanged
from a year ago—an excellent achievement—and will lead to a startup ofaccelerator operations in support of the research program in the 3rd quarter of
JFY2008.
Despite impressive progress in many areas the ATAC identified several
areas of concern that the committee feels will require particular attention tobring the J-PARC accelerator project to successful completion:• Main Ring performance• RCS performance with the 181 MeV LINAC• Performance of rf accelerating cavities for the RCS and 50 GeV MR
during the operations phase- 13 -• Planning for the commissioning and the transition to operations
These items are discussed in detail in the ATAC report, and are simply
summarised here.
Main Ring Performance
Good progress has been made on many fronts over the last year. Dipole,quadruple, and sextuple magnet installation are roughly 90% complete andvery significant progress has been made on the rf structures problem
identified last year. Activities are aimed at a May 2008 start of beamcommissioning, consistent with last year’s schedule.
Accelerator modeling has incorporated several improvements suggested by
the committee a year ago. However, the modeling presented indicates thatthe loss budget for the MR (450 W on an individual collimator) cannot be
met with a beam power above 150-200 kW. The committee regards this as aserious issue that must be overcome. The ATAC recommended areassessment of operating scenarios aligned with a performance goal of 450
kW based on the Phase I configuration. Such a reassessment could include
increasing the loss budget at 3 GeV, means for providing longer bunches,
and/or possible reduction in the cycle time. In addition the ATAC
recommended a reexamination of the decision to operate the neutrino
program at 30, rather than 40, GeV.
The IAC agrees with the recommendations of ATAC that areassessment of operating scenarios be aligned with a performance
goalof 450kW in the main ring based on Phase I configuration.
As a second concern, serious problems have been identified in the extraction
kicker including failure to meet both rise time and voltage requirements.
Potential solutions have been identified but will take a while to confirm andimplement. A strategy has been developed for operations through thesummer of 2010 including: a MR operation with 6 bunches, rather than 8,
and modification of the kicker magnet to increase the voltage capability. The
ATAC notes that this mode of operation implies a 25% reduction in beam
power. Development and installation of a kicker meeting the performance
specification is a high priority item.
In consideration of the above situation the ATAC concurs with prior years’assessments relative to MR performance with a 181 MeV LINAC, namely:
0.45 MW should be achievable in this mode contingent on resolution of theloss management and kicker issues described above. The committee remains

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convinced that a necessary component of any path to 750 kW in the MR
includes a 400 MeV LINAC.
RCS Performance With the 181 MeV LINAC
Excellent progress has been achieved on many fronts over the last year. Verysignificant progress has been made on the rf structures problem identified
last year. Installation is well advanced and hardware commissioning has
begun. These activities are heading towards a September 2007
commissioning period, consistent with the schedule established a year ago.
While there is little float associated with this milestone, the committee
regards the September beam-commissioning goal as achievable. Accelerator
modeling has incorporated several improvements suggested by thecommittee a year ago. The modeling demonstrates, and the committee
continues to believe, that the full potential of the RCS will not be realised
until the injection energy is raised to 400 MeV.
The ATAC believes the collimators still represent a major performance risk.
The collimation design requires that the 4 kW of loss power be distributed
over the ten collimator jaws in a manner than none receive more than 400700 W of load. The simulation presented to the committee indicated that theindividual jaw specification would be achieved with 20% margin at 0.6 MWof total beam power. The committee does not regard this margin as adequate.
The IAC agrees with the recommendation of ATAC that improvement
plan for the RCS collimation system to provide sufficient margin tocope with realistic operations scenarios.
In addition, the simulations show that the 4 kW loss budget cannot be met
with a delivered beam power beyond 300 kW, based on a 181 MeV injectionenergy. The simulations extrapolate satisfactorily to 1 MW of beam powerwith a 400 MeV injection energy.
In consideration of these issues, the ATAC concurred with prior years’assessments relative to RCS performance, namely: 0.33 MW beam power
represents a lower limit on achievable performance in the RCS with a 181
MeV injection energy. A beam power between 0.4 and 0.6 MW remains
plausible, but will require successful solutions to the collimator issues
described above. The committee remains convinced that a necessarycomponent of any path to 1 MW in the RCS includes a 400 MeV LINAC.
A decision to forgo the restoration of the full 400 MeV LINAC beam energy
would likely result in a factor of 1.5 to 2.9 reduction in integrated beam

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power, and therefore scientific productivity, from both the RCS and the MR
relative to the full capability of the facility over the long-run.
An important consequence of this would be a serious effect on the timelinessof the neutrino program as well as the early realisation of international
attractiveness of the neutron and muon facilities. Full realisation of thecapabilities of the J-PARC facility cannot be achieved with the current 181
MeV LINAC energy.
Recommendation 3: The IAC again recommends that the 400 MeV
LINAC capability be restored as the immediate priority following
successful completion of the Phase I construction project and thetransition to initial operations. This should not be achieved at theexpense of the fullest user program.
RF Cavities for the RCS and MR
Significant effort has been invested in the last year in overcoming theserious difficulties that had become evident in the accelerating structures for
the RCS and MR. Great progress has been made on understanding the sourceof a variety of problems, developing a strategic approach that addresses
short, long term, and, initial operations needs, and engineering innovative
solutions. As a result cavity fabrication and testing is proceeding and four(of the 10 required) rf stations have been tested and are now installed in the
RCS.
A very significant mobilisation of effort was undertaken over the last year toaddress the rf issues. Two new test stands were brought on line, one at KEK
and one at JAEA, supporting extended testing of a wide variety of cavity
configurations.
The initial RCS rf system is being fabricated from uncut cores, augmented
by parallel inductors to provide the required cavity Q. Water cooling has
been retained. Performance on the test stand has been good. All stations are
subject to 300-hour high power testing before installation in the RCS.
The initial MR rf system is being fabricated from cut cores, with the gap
subject to diamond polishing. This process eliminates the acid etch that wasdeemed the primary source of the problems. Two such accelerating cavities
have been successfully subjected to more than 1000 hours of high power
testing. Only five cavities are planned to be available for commissioning.
Adequate resources remain to be allocated for modifying an existing- 16 -

prototype, which would provide a sixth system, as recommended by the
ATAC.
In acknowledgement that problems could occur over the long term an R&D
team has been assembled and is investigating the possibility of developing acavity using oil as the cooling medium.
The ATAC believes the strategy being pursued is technically sound and islikely to support the needs of the J-PARC complex throughout
commissioning and the first year or two of operations. However, long-term
performance remains a risk. The ATAC recommended retaining the highpower test stand at JAEA, augmented by the construction of one additionalrf system of each type to support longer-term development.
Commissioning and Initial Operations Planning
The ATAC found fairly detailed plans covering the period of final
installation and commissioning of the RCS and MR. These were considered
to be well thought out and sufficiently detailed. However, the committee did
not see the level of integration across machine boundaries, the identificationof required resources, and the specification of required high-levelapplications that they would have expected. In addition the RCS plan did notextend beyond the start of MR beam commissioning, while the MR plan
extended through first year of operations. The ATAC believes thatsuccessful integration of the commissioning activity and the transition tooperations can only be accomplished under the direction of a full time
dedicated leader with the responsibility and authority for commissioning theaccelerator complex.
In addition, we recognise that performance expectations, both in the nearterm transition to operations as well as in the long run, remain to becommunicated with the various user constituencies. Those expectations,which need to be clearly defined and communicated, include beam power,
anticipated availability, user “production” hours, as well as beam quality
measures as required. The ATAC offered a recommendation in this regard,
and the IAC strongly concurs:
Recommendation 4: The IAC recommends that a commissioning teamleader with responsibility and authority for coordinating thecommissioning of the entire J-PARC complex, including the transition
to operations. An integrated commissioning plan should be developed

- 17 -

containing the roadmap towards Phase I design goals and defining
technical, schedule, cost, and personnel requirements. The integrated
commissioning plan should be discussed with, and made available to,the user community. The published plan should include estimates of
performance, anticipated reliabilities, and the time allocation between
users and accelerator physics.
A concern at this stage of the project is the availability of critical spares; inparticular, those “one-of-a-kind” components with very long lead-time. The
IAC strongly endorses the ATAC recommendation with regards toperforming a risk-based spares analysis and acquiring the critical spares.
The measurement of LINAC output beam quality parameters is essential toensure that input design specifications for the RCS are achieved. We urge aconcerted effort to measure and understand the critical beam quality
measures at the next opportunity. The strength of the J-PARC accelerator
team is evident in the progress to date. It is important to sustain that level offocus into the operating phase of the project.
Recommendation: The IAC urges that the plan for involvement andengagement of KEK staff in accelerator operations, improvement andupgrades be formulated already at this stage.
A number of interface issues exist between the accelerator and theexperimental facilities. The IAC encourages continued dialogue through thecommissioning team leader to manage those interfaces. The IAC feels that it
would be appropriate for the ATAC to consider those interfaces, inparticular between the accelerator and neutron production target. In addition
the IAC asks how is J-PARC receiving independent advice on the deliveryof beam from the accelerator system to the experimental facilities (the MLS
target and the neutrino experiment)? These beam lines will be among thehighest beam power transport systems worldwide and independent advice isnecessary.
Expectation Management
In the section on the user office we mentioned an important role ofexpectation management. This point was also raised by N-TAC. There is aneed to manage what the users are expecting from the accelerator as it ramps
up in power against what can actually be delivered at a particular time. As
illustrated above, the whole accelerator system is a complex entity whose

- 18 -

optimum parameters for delivery of expectations are interdependent.
Optimum parameters will be achieved when energy recovery of the LINAC
has been done and compromises made for lower energy injection eliminated.
This is most important in the delivery of the highest power for the neutrino
target (below) but also in bringing the materials and life science facility to
the top position in the world from the points of view of the power delivered
to the target, the number of instruments available and the interfacing of those
instruments to the national and world user community.
HADRON AND NEUTRINO EXPERIMENTS
We first address the two nuclear and high-energy thrusts we heard described
and then address an organisational issue that will be important to all users of
J-PARC.
As initial hadron experiments J-PARC has chosen appropriately a number ofexperiments involving hypernuclei. The proponents of these experiments areresearchers who have led similar experiments at facilities with lesscapability in flux and instrumentation at KEK and the AGS and so areprimed to do these experiments efficiently and effectively. They will be able
to use some components developed for earlier experiments and aredeveloping better ones. The cost and size of the experiments are modest andare thus also appropriate for an initial program. While the experimental hall
looks to be in an early stage of development, the hadron program appears to
be on schedule and once beam is available should be able to come on line
quickly.
The T2K experiment to send neutrinos to Kamiokande is an exciting one but
also one that is of a very different size and complexity to the experiments
described for the hadron program. As such, it has different requirements.
The experiment has a multitude of funding sources and many collaboratorsfrom different countries. Thus, it requires a much more formal management
structure to assure that it is built on time and within budget. Whilesignificant progress is being made on a number of subsystems we cautionthat the current management structure appears to be too informal and suggest
a project director be appointed to manage the day-to-day construction phaseof the project. This is a different coordination requirement to that in
Recommendation 4.
Since an experiment of a similar nature (K2K) was performed at KEK it
would also seem to be appropriate to draw more on the expertise involved in- 19 -

that experiment to aid in building T2K in as efficient and cost-effective way
as possible. There is another caution that the experimenters need to be awareof: their expectation of a 5-year experiment at a beam power of 750kW mayturn into a significantly longer time because with the current LINAC themaximum beam power is expected to be 450kW. It is important that the
LINAC energy is increased to 400 MeV, but it is also important that the
proposers and J-PARC Directors communicate regularly about expectations.
There is currently a missing part of the J-PARC organisation that will impact
T2K, but will also impact all types of users and experiments. Specifically, ata user facility like J-PARC it is crucial that there be a technical support
organisation that helps experiments get up and running. Such organisations
exist at all successful major user facilities in the world and as J-PARC will
be a facility with outstanding capabilities it is vital to create such anorganisation. This experiment support organisation provides local
knowledge of how to get things done with resources that are either internalor external to the lab. It also helps provide a link between the experimenters
and the accelerator operations.
COMPUTER NETWORKS AND REMOTE ACCESS
A layered approach to user access to computer networks at the Tokai
campus is recommended. It will be an expectation that all visitors to the JPARC campus are able to achieve seamless wireless access to facilitate
interaction with their home institution via open access to the internet – bothfrom within the J-PARC Center, Guest House and Support Laboratories. JPARC users will require restricted and controlled access to J-PARC systems,in order to monitor experiments and access data.
Some specificcollaborators will require privileged access to J-PARC system in order toremotely control experimental systems and diagnostics.
As an example of the later category, the T2K collaboration has alreadyidentified the need for experts resident in partner institutes worldwide tohave such access to systems associated with the neutrino target, neutrino
detectors and beam transport. Such privileged access – with administrator
authority over appropriate subsystems – is standard for international
laboratories – but needs to be limited and demonstrated to be secure withrespect to JAEA systems.

- 20 -

MATERIALS AND LIFE SCIENCES
Target System
The IAC was able to inspect the neutron target system and associatedhandling equipment as it was being assembled. The committee was seriously
impressed by the quality of technical construction in the Materials and Life
Science target station. The whole facility illustrates the care and ingenuity
in design and construction of this essential element that was analysed indetail in the N-TAC Committee report from its November 2006 meeting.
Development work for the minimisation of damage in the target as it accepts
progressively greater power from the accelerator must continue to occur.
The standard of realisation of remote handling systems is exceptional, andwill surely pay dividends in easing potential operational difficulties in theyears to come. The suggestions from the N-TAC are endorsed and the credit
for the present progress reiterated.
Instruments
The committee congratulates J-PARC on progress and is impressed by boththe quality and innovative nature of these plans. Good progress has also been
made in developing advanced capabilities in techniques such as optics, novel
detector systems and focusing and polarising devices: this activity must
continue to be funded and expanded through international collaboration.
The suite of six instruments available when the beam power is first delivered
to the target and the moderators supplying them with neutrons are "on track"
for initial operation, a fact which reflects to the great credit of the instrument
team. These new instruments will be at least as good as the best in the world.
What is lacking are the funds for the next group of instruments and there aremany very interesting proposals awaiting this. The contribution to thecurrent success from the Ibaraki Prefecture is once again acknowledged as is
the expertise coming from both JAEA and KEK scientists.
For the neutron scattering area the increase in intensity at J-PARC - possibly
even in its first year of commissioning, will be nearly an order of magnitude
higher than KENS - the former KEK facility. An increase in the number of
instruments in the period 2008-2011 would surely be a very good investment
from the point of view of scientific return before energy recovery in the
LINAC is completed. The instrument portfolio after LINAC energy recovery
would then be able to take advantage of both an increased scientificcommunity as well as the new intensity available at the neutron target.

- 21 -

Standardisation of component systems and a strategic approach to thedevelopment of instrumentation in the Materials sand Life Sciences facility
is recommended. Experience world-wide – on both synchrotron and neutron
facilities - shows that a coherent approach under the control of the J-PARC
Center to design, operation, scheduling and support is to be preferred, tomaximise the impact of this key aspect of the facility.
J-PARC already has a core of highly skilled neutron scientists in their design
team. In operational mode, this will need to be expanded by attracting
specialists in a wide range of scientific disciplines – solid state physics,
materials science, soft matter, biology and engineering science - as well asbuilding up a team of technical support in detectors, data acquisition andanalysis, cryogenic systems and other sample environments. A vibrantscientific atmosphere needs to be established in the J-PARC Center – toattract and retain such marketable staff and to make the user experience
world-class. Cross fertilisation of ideas in this interdisciplinary atmosphere- between users and staff alike - will be a hallmark of success at J-PARC.
Recommendation 5: The IAC recommends a model for operation where"in house" scientific staff have the dual responsibility of supporting theuser program and developing an individual research program. In
addition, some staff - scientists, engineers and technicians will be needed
to maintain and develop the facility

User Interface
The Materials and Life Science facility at J-PARC should be capable ofproviding for thousands of users each year when in full operation. Theseexperiments are "small science" where the quality of the infrastructure
related to experiments has a big impact on the complexity of experimentsthat can be attempted. As we expect J-PARC to be at the "cutting edge" ofneutron science, the secondary infrastructure should also be world class.
In practical terms this means that many samples (particularly chemical andbiological samples) may have to be prepared within easy reach of the
instruments. Associated laboratory facilities as at the best international
centers Institut Laue-Langevin, Grenoble, NIST USA, SNS USA, and the
OPAL reactor Australia, must be of high standard and furnished, through theoperating budget, with adequate materials and support instruments to make- 22 -

sure that all samples are in the best condition before neutron experiments are
performed. This should be the responsibility of the user office.
Related to this is the provision for external access and accommodation forlarge numbers of visitors (national and international) as well as theelectronic access to data during measurement and standardised dataprocessing programs maintained by the J-PARC Center. The matter ofRecommendation 5 also bears upon this issue of the expectations of visiting
users. Other major centers in neutron scattering have all of this available andit is especially useful for new users who often bring new types of problems,
whose data can be treated - at least in the first instance - by the standard
programs. This is another aspect of expectation management - a particularly
important one - for ensuring change and renewal in the scientific program in
neutron scattering.

Recommendation 6: The IAC urges the J-PARC Center to develop plans
for the strategic population of the Neutron and Muon Instrument Suite,
creating, as early as possible, a balanced portfolio to satisfy the large
and dynamic Materials and Life Science Community in Japan.
MLF Muon Facility
The construction of the Phase I MLF Muon Facility is nearing completion. It
includes the muon target complex with four secondary beam ports and the 3GeV proton channel from RCS extraction to JSNS (tunnels M1 and M2).
For phase I, the existing superconducting decay channel of KEK will be
moved to J-PARC and installed in one of the ports. It will produce a wide
spectrum of µ+ or µ- with first beam expected in fall 2008. It could be
supplemented initially by a surface muon facility provided by JAEA-ASRC
or by a second extraction provided by Toyota Labs as a core project.
The other muon beam lines are scheduled to be built in phase II. They willcomprise multipurpose surface muon beams suitable for a large suite of µSR
experiments, and as an important new development, a high acceptancesurface muon channel coupled to the “Dai Omega” beam line, which could
be used for producing ultra-slow muons of highest intensity and luminosity
applicable to studies of materials surface phenomena. This beam, based on a
new special method of muonium laser ionisation was developed by Japanesephysicists from KEK working at the RIKEN-RAL facility at ISIS and will
open attractive and unexplored research fields.

- 23 -We recommend, that the construction of the “Dai Omega” channel
receive the highest priority of the phase II muon projects.
Concerning the time structure of the 3 GeV proton beam there is still a
conflict between crucial needs of the muon experiments to obtain a pulse
width below 100 ns and accelerator requirements of maximising intensity.
We recommend that the accelerator team continues to work on
reducing the 3GeV proton beam pulse width to 100 ns or less.

NUCLEAR TRANSMUTATION
The feasibility of transmutation through neutron irradiation is well established from ascientific point of view; fast neutron spectra have a high potential for transmutation.
Future nuclear reactors (Generation IV) using fast neutrons are expected to significantly
reduce the amount of wastes by transmutation. Their commercial development is
expected beyond 2040.
Japan has planned an outstanding R&D program on transmutation in the Monju sodium
reactor and in J-PARC using a hybrid system using the J-PARC accelerator coupled to a
subcritical reactor. R&D has a major role to play in clarifying the technical feasibility oftransmutation and assessing the gain achieved with regard to the radiotoxic outcome. The
IAC believes research on nuclear wastes management is of special importance for thedevelopment of nuclear energy since public perception of nuclear energy in many
countries is that there is no satisfactory solution to the long term problem of nuclear
wastes management.
The J-PARC nuclear transmutation programme was presented by H. Oigawa. The
objective of the programme is to study in depth transmutation to reduce the radiotoxicity,
volume and heat of high level nuclear waste that has to be put in a final repository. In its
previous report, the IAC reaffirmed its full support to the J-PARC nuclear transmutation
project and recommended that “J-PARC transmutation programme should be integrated
in an international roadmap. The user community should be developed in Japan and inother countries in particular in Asia.”
The IAC was most pleased that collaboration with SCK-CEN was concluded on
November 23, 2006, on ADS design, material studies and Pb-Bi technology. H. Oigawa
and his colleagues also collaborate on the MEGAPIE spallation target at PSI in
Switzerland. Following the recommendations of the IAC they have joined the European
project EUROTRANS, proposed by a large collaboration of research institutions together
with industry partners.
The IAC believes that now the J-PARC group is well integrated as part of the efforts of
the international ADS transmutation community. The IAC strongly recommends J-PARC
to continue its efforts to network the ADS activities with international partners.

- 24 -The proposed programme of the J-PARC TEF facility will benefit from these studies andwill be in a unique position to provide important information on the potential of ADS for
nuclear waste management and advanced materials. This programme should establish the
ADS efficiency for transmutation. Information on possible high power operation
feasibility of sub critical systems is still to be demonstrated.
The IAC committee believes that ADS research at J-PARC, will need increased support
to realize the full potential of the facility. The J-PARC group should be in close contact
with the other groups from JAEA to contribute to the next “JAEA 5-year plan”. This plan
will be critical to find the resources needed to complete the accelerator and build the TEF
facility.

- 25 -

APPENDIX IAgenda for the 6th International Advisory Committee Meeting
J-PARC
Date: March 5 (Mon) and March 6 (Tue), 2007
Place: J-PARC Center – Tokai
March 5 (Mon)8:50 - 9:10
9:10 - 9:30
9:30 - 9:50

Executive Session
Committee + Nagamiya, Oyama, Yamazaki
JAEA and J-PARC
K. NodaKEK and J-PARC
F. Takasaki

9:50 – 10:10-- Coffee Break –10:10 – 11:10

Status of J-PARC- J-PARC Center- User Policy
Accelerators- Progress report- A-TAC report

11:10 – 12:30

12:30 – 13:30
13:30 – 15:00(13:30-13:40)(13:40-14:20)(14:20-15:00)

S. Nagamiya/Y. Oyama

Y. Kamiya/Y. Yamazaki
S. Holmes-- Lunch –Nuclear and Particle Physics Experimental Facility- PAC report
J. Imazato- Hadron Experiment
T. Nagae- Neutrino ExperimentDavid L. Wark
（T2K Co-Spokesperson, Imperial）

15:00 – 15:30-- Coffee Break –15:30 – 17:00(15:30-16:20)

Material and Life Science Experimental Facility- Progress report of Neutron
Y. Ikeda
Status, Neutron Source, Instruments, Organisation, Access Policy,
LOI and N-TAC report(5min reserved)- Progress report of Muon
Y. Miyake- MUSAC report
J.-M. Poutissou(16:20-16:45)(16:45-16:55)
17:00 – 17:30

Nuclear Transmutation

17:30 – 18:30

Closed Session

18:30 -

Reception (Akogi-ga-ura Club)

March 6 (Tue)9:00 – 9:15
9:15 – 9:30
9:30 – 9:50

Network and Computing
Users Office
Future Plan
LINAC recovery, Second phase

H. OigawaS. Kawabata
M. Ieiri
S. Nagamiya

- 26 -

10:00 – 11:30

Closed Session & Working

11:30 – 13:00-- Lunch –13:00 – 15:30-- Site Tour --15:30 – 16:30

Working Hour- 27 -

APPENDIX II
Committee Members
BOND, Peter

Deputy Director, BNL, bond@bnl.gov

CHEN, Jia'er

President, National Natural Science Foundation, China.
chenje@pku.edu.cn

FROIS, Bernard

Director, New Energy technologies, CEA, Paris, France
bernard.frois@cea.fr

FUKUYAMA, Hidetoshi

Professor, Tokyo University of Science,
fukuyama@rs.kagu.tus.ac.jp

HENDERSON Stuart

Director, Research Accelerator Division, SNS, Oak Ridge,
shenderson@ornl.gov.

HENNING, Walter

Director, GSI, Darmstadt, Germany
henning@gsi.de

HOLMES, Steve

Associate Director, Fermilab, USA. holmes@fnal.gov

PETITJEAN, Claude

Deputy Head, Laboratory of Particle Physics, Paul
Scherrer Institute, Switzerland. claude.petitjean@psi.ch

POUTISSOU, Jean-Michel Associate Director, TRIUMF, Vancouver, Canada.
jmp@triumf.ca
SUZUKI Yoichiro:

Director, Institute for Cosmic Ray Research,
University of Tokyo. suzuki@icrr.u-tokyo.ac.jp

TANAKA, Satoru,

Professor, University of Tokyo, s-tanaka@q.t.u-tokyo.ac.jp

TAYLOR, Andrew

Director, ISIS, UK. adt@isise.rl.ac.uk

WHITE, John W.
(Chairman)

Professor, Australian National University
Canberra, Australia, jww@rsc.anu.edu.au