Neutron Advisory Committee Meeting for J-PARC MLF Facility
NAC2016
Tokai 23-24 February 2016
Committee members:
Robert McGreevy (chair), Dimitri Argyriou, Bertrand Blau, John Galambos, Yoshiaki Kiyanagi,
Chang Hee Lee, Dan Neumann, Jamie Schulz, Mitsuhiro Shibayama and Masaaki Sugiyama.
The committee thanks the participants for the detailed presentations and their helpful and open
responses to the discussions. The committee highly values the hospitality and excellent support provided
during the committee meeting.
Charge to the committee:
1. Review the recovery process from the target incident at MLF:
1.1 adequacy of the renewed target development strategy in the context of 1 MW stable
operation in the foreseeable future
1.2 appropriateness of program handling including execution of approved proposals as well as thecall for new proposals
2. Evaluate the appropriateness of the facility operation and its upgrades with respect to thefollowing points:
2.1 safe, stable, and efficient operation towards the production of science in timely manner, evenwith limited beam time available in CY2015,
2.2 timely construction of beam lines and sample environment to maintain the uniqueness of thefacility attracting not only domestic users, but also international users.
3. Any suggestions for improvements are appreciated. Our particular concerns include, but are notlimited to, the following:
3.1 yet to be unified MLF activities between JAEA, KEK, CROSS, and Ibaraki-prefecture, as pointed
out at the last NAC
3.2 improving paper production rate (per proposals, per MW-hours)
3.3 promotion of industrial use
3.4 beamtime balance11. Review the recovery process from the target incident at MLF
1.1 adequacy of the renewed target development strategy in the context of 1 MW stable operation in
the foreseeable future
Findings
The independent review of the target is welcomed and the review committee is thanked for their oral
report to and discussion with the NAC. The review report will provide more detailed feedback than given
below.
The overall target redesign response is sound. The vulnerabilities from stress concentrations are being
addressed and weld lengths / bolt numbers are all being reduced. The move toward a constraint freedesign (decoupled water and Hg vessel shrouds) is also good.
The proposed enhanced fabrication inspection with the vendor is appropriate. Maintaining goodcommunication between the fabrication and design efforts is important for evolution towards a robusttarget. Independent fabrication qualification is also encouraged.
The proposed schedule for design completion and fabrication of target 8 is aggressive (see figure). Careshould be taken not to rush design or fabrication steps. Ensure the delivery of a high quality target, evenat the expense of a delay in the change from target 2 to target 8 (with extended operation at reducedpower).

The schedule for target 9 (constraint free) design/fabrication and the plan to reach 1 MW operation iseven more aggressive. The possibility of additional target failures should not be ignored in operational
planning. Contingency analysis on additional failure impacts should be done (target storage, replacement
times, impact on the user program, etc.) as part of the risk assessment. Establishing a reliable operationbase is critical.
Higher power operational periods shortly before planned target changes are an appropriate (reducedrisk) mechanism for high power operation testing in the near term.
Recommendations
The highest priority for MLF is to provide reliable neutron beam instruments and operation to theirscientific community. The production and support to science needs to be prioritized ahead of reaching2the technical goal of 1 MW. Extended (reliable) operation at 200kW would benefit both the scientificprogramme and the target programme.
1.2 appropriateness of program handling including execution of approved proposals as well as the callfor new proposals
Findings
The approach taken with regard to carry over of experiments and priority being given to external users is
consistent with that used by other facilities for unplanned outages.
Recommendations
When beamtime is reduced, increased priority should be given to external users. (This is not obvious fromthe statistics provided.)
The approach to reducing the target replacement time should be supported and could possibly be takeneven further.
1.3 approach to moderator cryogenics (not included in the formal charge)
Findings
An additional issue, not directly related to the target incident but linked in terms of future operational
availability, is apparent contamination of the hydrogen moderator cryogenics system. The approach of JPARC’s cryogenic team to tackling this issue appears to be very professional. They have clearly identified
the problem and excluded many possible causes. The proposed further measures appear to bereasonable and achievable. The present situation with reduced helium flow and intermittent operation
can only be an intermediate solution and every possible effort must be taken during the coming summer
maintenance period to identify the cause of the contamination and the method for its elimination.
Recommendations
There are several devices on the market measuring in-situ the oil mist and the CxHy content in He flow.
Some of them require an extra pyrolyser unit. Contact specialists from other institutes or from suppliersof He refrigerators in order to get advice as it appears that J-PARC is not the only facility facing this kindof problem.
It is difficult for the committee to judge the acceptable level of oil contamination. In principle the levelshould be as low as possible, i.e. in the ppb range. However, it is important to monitor the oil mist
concentration over an extended period of time (several months) to get an indication of the tendency. Ifthe concentration significantly increases over time the refrigerator should be stopped and cleaned.

32. Evaluate the appropriateness of the facility operation and its upgrades with respect to thefollowing points:
2.1 safe, stable, and efficient operation towards the production of science in timely manner, evenwith limited beam time available in CY2015,
2.2 timely construction of beam lines and sample environment to maintain the uniqueness of thefacility attracting not only domestic users, but also international users.
Findings
MLF is almost fully instrumented with only two available beam ports for new beam lines. The
instruments that have been constructed are among the best in the world in their respective class. The
variety and support from the community in developing instruments shows strong community interestand engagement. This is a fantastic achievement that the NAC applauds. The NAC notes that the NIPRC
has made recommendations for jBIX, a next generation instrument for macromolecular crystallography,
and for a polarized epithermal neutron spectrometer. If both were eventually funded and built this would
result in all of the neutron beamlines at the MLF having been instrumented.
Due to budget constraints, many instruments have unfortunately not reached their potential. The NAC
notes and appreciates the efforts to find resources to get the MLF instruments to full scope. However
this process appears to be uneven among the partners at the MLF.
Progress in neutron optics, detectors, and polarization devices is similarly outstanding, with the 3He
polarization in spin filters finally reaching more than 80%. Regrettably, the NAC was not similarly
informed about the MLF’s efforts in sample environments.
Recommendations
The ‘grand plan’ developed at the start of MLF construction was an excellent tool for developing acoherent instrument suite to service the needs of the scientific community. It is now time to update thisplan by developing a coherent scientific strategy that sets a vision for the future development of the MLF
on the basis of the needs of the community and the impact of the science that can be achieved. Then alignall the instrumentation and development activities to achieve this vision. This would require developing
prioritized lists for completing the full scope on the existing instruments, for the development of sample
environment, and for the development of neutron technologies. While many avenues may be attractive
and exciting, with the limited resources available it is likely impossible to be truly excellent in all of thedevelopment activities being undertaken and in all types of sample environments.
This scientific strategy should also inform an independent assessment of where the best scientificopportunities lie for instrumenting the last two remaining beam-ports. The current choice of instruments
may not be the best ones if viewed in the light of other options.
Finally this strategy should discuss the future challenges that can be addressed using neutrons and how a
2nd target station (STS) may address them. Use these scientific priorities to develop a technical concept
for a STS (in terms of pulse lengths, rep-rate, power and moderators) that will be utilized by an
instrument suite that will meet these future scientific challenges. To secure a 2nd target station it isimportant that MLF develops a user community that will be able to fully exploit the new capabilities. This
will likely require that the 1st target station be fully exploited. Thus it may take several years to reach a
productivity level that clearly demonstrates the need for the capacity and capabilities that can beprovided by a 2nd target station. In spite of this, it is time to incorporate a second target station into thelong term plans of the MLF.

4The plan for harmonising the allocation of beamtime on the different funded beamlines is commended.
The merits of the introduction of the new General (Long Term) proposal access type should be carefully
considered as experience from other facilities is that this has not delivered an increase in scientific output
from the facility.
It was clearly evident that the general user program is not adequately supported on some beamlines
which are hampering the delivery of the scientific outcomes. The committee urges J-PARC to determine
strategies to increase the conversion-rate of raw data to publication.
The committee is pleased to see progress being made with the local community regarding the new site
access entry for J-PARC. This will streamline access to the J-PARC site for users and benefit the local
community by reducing traffic congestion.
It was unclear whether the views or the satisfaction of the user community were considered in a numberof presentations. The committee encourages the introduction of a process to survey users shortly after
the completion of experiments to gauge their satisfaction and allow determination of their concerns.
Items that may be considered in the survey include data acquisition and reduction software, security,performance of the beamline/sample environments.
The committee had difficulty in understanding the metrics and data reported throughout thepresentations. Specifically some data reported was not self-consistent and incomplete. The committee
encourages J-PARC to consider using the metrics and data that is reported for other facilities to permit
comparison and clearly identify trends, e.g. number of experiments and publications per beamline peryear.

53. Any suggestions for improvements are appreciated. Our particular concerns include, but are notlimited to, the following:
3.1 yet to be unified MLF activities between JAEA, KEK, CROSS, and Ibaraki-prefecture, as pointed out
at the last NAC
Findings
The most concerning point is that each organization (JAEA, KEK, CROSS, Ibaraki) has its own program andstrategy, and very different levels of resource to support the different instruments. The most successfuluser programmes, for example ILL, have been built on consistency of approach to access and support.
The current situation about beam time allocation is very complicated and difficult to understand. Hence,
it should be improved (or simplified). The future plan for the beam time structure for Facility Use (aspresented by Kawakita) is one way to go. That is simplification to two categories - Instrument Group
Proposals and Facility Projects. Instrument Group Proposals (public; JAEA) and CROSS development
proposals (CROSS) become Instrument Group Proposals. Project Research Proposals (public) will berenamed as Facility Projects. S-type Proposals (KEK) will be divided between Instrument Group andFacility Proposals (S1) and to general user proposals (S2). This kind of change is certainly better thandoing nothing. However, even further simplification would be desirable.
Recommendations
The NAC understand that to move all MLF staff and funding into one organization is probably impossible.
Accepting this fact, the next best approach would be to structure and control activities so that theyexternally (for users) appear to be one organization. The leader of this organization should (literally) bethe MLF Director. The different organisations contributing to MLF need to develop a common strategy
that accommodates their individual strategies – this may require some compromise but given that all
have a strong interest in the future productivity and success of MLF there should be a lot of commonground. Structuring activities across instruments by common interest (e.g. diffraction) rather thanorganization (e.g. KEK) may help to foster a sense of common purpose and enable more uniform sharingof resources.
3.2 improving paper production rate (per proposals, per MW-hours)
Findings
Even when the unplanned shutdowns are taken into account, the paper production rate of J-PARC/MLF isworryingly low relative to the number of experiments that have actually been performed. In 2012 and2013 a total of 564 experiments were carried out, leading to 101 papers in 2014 and 2015 – the target
should be about 1 paper for every 2 experiments. A possible cause is the lack of man-power on some
instruments, so instrument scientists do not have enough time to follow-up their (user) experiments untilpublication. However, even the better staffed instruments have low publication rates.
Experience at other facilities is that publication rates are only marginally related to source power. As
power increases it enables more complex experiments, not just more experiments, and the number ofexperiments that can in practice be supported is limited by staff and budget levels. The best metric istherefore publications per experiment performed (not proposals submitted or accepted).
Recommendations
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Better data is required before the NAC can make any clear recommendation (aside from the obvious
issue of the staffing level – see below). MLF should ask instrument scientists to carry out an in-depth
analysis of all the experiments (internal and external users) that have so far been carried out. Where
experiments have not led to a publication, contact the users and ask why. Typical reasons might beinsufficient data quality, more beamtime needed to complete data collection, additional data needed(from other techniques), data analysis/software problems, insufficient time/people to analyse/publish,
require assistance from facility etc.
The average level of staffing on instruments is certainly below that of other internationally leading
facilities. If this is leading to low productivity when MLF is operating at 200-500kW, then the situation at
higher power (more data, more complex experiments) will simply be worse.
For some of the younger instrument scientists, closer collaboration with academia may help. Facilities,
with their smaller number of scientists and quite strong emphasis on technical aspects, are a more
limited environment for scientific development than universities. A “mentor” system, pairing instrument
scientists and university professors, might be helpful for the development of broader scientificperspectives and productivity improvement. Note that this recommendation only relates to theprofessional development of the instrument scientists. We do not recommend building special
relationships with regard to access to beamtime.
3.3 promotion of industrial useFindings
The MLF places a high value on industrial engagement with approximately 20% of the successfulproposals being led by industry. This is the highest fraction of any major neutron facility in the world.
They recognize that the needs of industry are different than those of academic users and have somemechanisms in place to accommodate the differences. There is also a very healthy fraction of proprietary
work for which the companies pay the full cost of providing the beam time, though unfortunately theMLF does not actually receive the money generated by these experiments. Instead the funds are paid
directly to the government. Overall, the NAC congratulates the MLF on their very effective program forindustrial engagement.
Recommendations
NAC strongly recommends industry collaboration (and/or consultation) with academia (experts onneutron scattering, theories, synthesis, etc) to further broaden industry participation and make output
more productive.
As the MLF clearly recognizes, industry needs rapid access to the facility. In light of this, the NAC
encourages them to expand the rapid (two week) access to powder diffraction to other instruments. Inaddition we believe that the commissioning of the imaging station presents the MLF with an excellent
opportunity for future growth of industrial use of the MLF. The NAC also believes that the MLF should
explore additional ways to attract industrial use of the facility. This could for example, include othermechanisms of access to the MLF instrument suite through joint projects with MLF scientists requiring
some sort of contract to spell out IP issues, web meetings to help industrial scientists learn how neutrons
can be used to help them solve their companies problems, and greater use of beamtime to demonstrate
the utility of neutron techniques to problems of interest to specific companies.
At present the impact of most of the industrial use is effectively invisible. The NAC recognizes that it isoften difficult to judge the effectiveness of such programs as counting papers is clearly inadequate. Thus
we recommend that the MLF develop a different set of metrics for their industrial engagement programs.
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Besides the number of successful applications for beamtime, which is already being tracked, thesemetrics could include the number of patents informed by neutron results, case studies of products whose
development was assisted by neutron experiments (such as the tyre rubber example), and even thenumber of companies that return to the MLF. This last one is actually a very good way to gauge whether
or not companies found enough value in their neutron results to expend their staff’s time to continue
using the facility.
MLF management should make it clear to the staff that industrial engagement is highly valued. For
example staff (including scientists) who are effective in attracting and assisting industrial scientists totheir instrument should be credited with these activities in their performance review. It is unfortunatethat the money generated through proprietary work is not returned to the MLF. If it was, it could partiallybe made available to the instrument scientists to improve the capabilities of their machine.
3.4 beamtime balanceFindings
The statistics are not easy to interpret, but the general impression is that the beam time balance looks
too much biased towards internal use. Japanese use of international facilities does not appear to haveincreased either due to the JRR-3 reactor out of operation or to the unplanned stoppages of J-PARC/MLF.
Thus suggests that potential users are not using neutrons, which increases the risk that they are lost tothe field. If the pipeline of trained students dries up due to lack of access then this will lead in the future
to a lack of postdocs and then of professors, which is not good for the long term future of MLF.
Recommendations
As in recommendation 1.2, the NAC strongly recommends giving increased priority to external users, ofcourse working in collaboration with instrument scientists.

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