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INTC 63 minutes Page | 1
CERN-INTC-2020-019
INTC-063
5 – 6 February 2020
ISOLDE AND NEUTRON TIME-OF-FLIGHT
EXPERIMENTS COMMITTEE
Minutes of the 63rd meeting of the INTC held on Wednesday and Thursday, February 5 – 6 2020
The chairperson of the INTC (Karsten Riisager) opened the meeting by welcoming the INTC referees
who were present and those via Vidyo. The meeting began with the facility reports followed by the
presentation of the submitted proposals. Presentations from the open session may be found at the
following address: https://indico.cern.ch/event/880289/
Facility reports during the open session
ISOLDE technical report (Joachim Vollaire) Joachim Vollaire presented an overview of the ongoing shutdown work at ISOLDE. The status of the
two front ends was presented. Front end 10 – which will be installed on the GPS – has been extensively
tested on the offline separator. It will be transported to B. 179 before civil engineering works begin for
the new nanolab. Once installed, hard ware tests will be followed by a commissioning programme. The
assembly of the new HRS front end (FE11) is now progressing well and is expected to be tested at
offline2 in April. Once this testing is finished, the front end is due to be installed in the target area in
June – once the possibility of access is restored following the completion of nanolab civil engineering.
The ISOLDE laser ion source – RILIS – is undertaking many upgrades. At MEDICIS the MELISSA
ion source became operational in 2019 and beams of Tb, Er and Yb were produced allowing for
collections of these radioisotopes. At offline2 a laser lab is being prepared which will utilise some spare
equipment from the ISOLDE-RILIS to allow for laser tests at the offline separator. This is expected to
be ready soon. At ISOLDE an extension of the reference area for both GPS and HRS will allow for the
independent setup and stabilisation of laser beams for both separators, which will result in a quicker
switchover between runs. The optical layout is being optimised and an upgrade of the laser systems and
their controls is underway.
At ISOLDE the tasks for the low energy beams are all on schedule and will be completed to allow for
commissioning with stable beams in the second half of 2020. Among these are the refurbishment of the
GLM/GHM area to better comply with current safety regulations; the installation of the new tape
station; the overhaul of the beam instrumentation on all beamlines and maintenance of the cooling
stations and ventilation systems. All cooling water will be restored at the end of February.
Similarly, the upgrades, repair and maintenance at REX/HIE ISOLDE are also on schedule.
Maintenance on the REX Trap and EBIS have been completed. RF consolidation on the REX LINAC
is complete and the installation of 3 additional diagnostic boxes is underway. The vacuum maintenance
is also complete. The 4th cryomodule has been repaired and has been transported back to ISOLDE from
SM19 on 21st January. The re-connection of the cryomodule is on track and recommissioning of the SC
linac is foreseen from July 2020. In addition the beam instrumentation throughout the hall has been
consolidated and upgraded including a newly designed SEMGRID which will be put into use for Run3.
The approval for the early start of ISOLDE in 2020 which was recommended by the Research Board in
December will allow for a comprehensive programme of machine commissioning and development at
HIE-ISOLDE and in the low energy area. Commissioning will also be available for physics setups in
the second half of 2020.
INTC 63 minutes Page | 2
Finally, a summary of MEDICIS in 2019 and its plans for 2020. In 2019 numerous sources of external
activity were imported allowing collections of 155Tb, 175Yb and 169Er. In total 870MBq was collected in
2019 and delivered to 4 of the collaboration institutes: PSI; HUG; KU Leuven and NPL. Eight targets
were produced and re-used up to three times. From January till March 2020 MEDICIS will have a
technical stop allowing for maintenance of the ventilation system along with a replacement of the
extraction electrode along with other shutdown tasks such as tests of the robot trajectories and exchange
of the laser windows. The facility will resume operation from mid-March with 155Tb collections.
Status of nTOF (Oliver Aberle) Oliver Aberle presented an overview of the nTOF shutdown progress: including the status of the EAR1
beamline, the exchange of the nTOF target and the status of the new control room.
The previous pulsing magnet has been replaced by a new permanent magnet. In addition a new SEM
grid will improve the beam diagnostics for this new target. The new target itself is progressing well in
its construction. It consists of a sliced pure Pb target which is cooled by N2 flow which is slightly above
atmospheric pressure. It is designed to comply with the physics requirements of the nTOF collaboration
and is on schedule for installation at the end of 2020.
The dismantling of the nTOF target required the collaboration of several technical groups but was a
success with a lower than expected cumulative dose received indicating the preparedness of the teams
involved. The new nTOF cooling station is also ready for installation: the next stage being confinement
of the nitrogen within the cooling circuit.
The shielding around the spallation target will also be reconfigured during LS2. It will be now moveable
and on rails, divided into 3 blocks. This will allow for more flexibility during running periods and will
permit occasional inspections of the facility. Unforeseen events such as flooding – which delayed a
restart in 2017 – can also be dealt with more effectively due to this new shielding. In addition to the
shielding replacement, this work will allow the anticipation of the Near Experimental ARea (NEAR)
for various applications in the future.
Within the experimental areas, the removal of all radioactive samples and a control of contamination
has been completed. The cabling campaign to remove the sweeping magnet’s cables is underway. The
recommendation from the ASN-OFSP for EAR2 is being followed up. In addition, upgrades and
consolidation of the alignment system, electronics laboratory, control room and DAQ are ongoing.
The new control room in B. 506 was handed over in December and will be set up with the DAQ upgrade
in early 2020. The schedule for the remainder of 2020 was shown and the commissioning plans for
2021 along with the future physics programme will be presented at the June meeting of the INTC.
Documents presented during the open session:
1. INTC-SR-095 & INTC-SR-096 IS626: Radiotracer diffusion of copper and potassium in
Cu(In,Ga)Se2 thin-film solar cells / IS627: Radiotracer diffusion in refractory high-entropy
alloys. Daniel Gaertner (University of Munster)
2. INTC-SR-097 Measurement of the 44Ti(alpha,p)47V reaction cross section, of relevance to
gamma-ray observation of core collapse supernovae, using reclaimed 44Ti. Alexander Murphy
(University of Edinburgh)
3. INTC-SR-098 Status report for the CRIS collaboration. Adam Vernon (University of
Manchester)
4. INTC-SR-099 Status Report on IS556 : Spectroscopy of low-lying single-particle states in 81Zn
populated in the 80Zn(d,p) reaction Riccardo Orlandi (JAEA)
5. INTC-SR-100 Cu(I), Ag(I), Cd(II), Hg(II), and Pb(II) binding to biomolecules studied by
Perturbed Angular Correlation of γ-rays (PAC) spectroscopy Lars Hemmingsen (University of
Copenhagen)
INTC 63 minutes Page | 3
6. INTC-SR-101 Lattice sites, charge and spin states of Fe in InxGa1−xN studied with emission
Mössbauer spectroscopy Hilary Masenda (University of Witswatersrand)
7. INTC-SR-102 Local Probing of Ferroic and Multiferroic Compounds Armandina Lopes
(University of Porto)
8. INTC-SR-103 Study of the unbound proton-rich nucleus 21Al with resonance elastic and
inelastic scattering using an active target Beatriz Fernandez-Dominguez (University of Santiago
de Compostela)
9. INTC-SR-105 β-NMR of copper isotopes in ionic liquids Monika Stachura (TRIUMF)
10. INTC-SR-106 Implanted 7Be Targets For The Study of Neutron Interactions With 7Be : (The
Primordial 7Li Problem) Moshe Gai (University of Connecticut)
2. Discussions during closed session: Thursday 7th November 2019
Present:
Karsten Riisager (INTC Chair), Richard Catherall, Marek Pfutzner, Enrico Chiaveri, Alessia di Pietro,
Thierry Stora, Gerda Neyens, Michael Doser, Andreas Gorgen, Arjan Plompen (via Vidyo), Iain Moore,
Katharina Lorenz, Joachim Vollaire, Antonio Moro, Kristiaan Temst, Sebastian Rothe, Karl Johnston
(INTC Secretary).
Excused: Maurycy Rejmund, Achim Schwenk
The minutes of the 62nd meeting of the INTC were approved without further comment.
Matters arising:
At the 62nd INTC a decision on SR-075 concerning IS538 was postponed pending feedback from the
group regarding questions which arose at this meeting: in particular the use of a higher energy and
different target substrates compared to the original proposal. A reply has been received from the
spokesperson and it was agreed to close this experiment (IS538) and a new proposal taking into account
the new demands of the collaboration will be submitted in November 2020. The INTC notes that the
3 shifts of IS538 are not retained after LS2.
Discussion of the Facility reports:
1. ISOLDE technical report
The committee welcome the approval for the early start-up for beam commissioning in 2020. This will
afford the operators valuable time to better understand the machine which will be to their benefit and
to the physics users during Run3.
2. nTOF status report
The committee congratulate the nTOF collaboration on the progress made during LS2 especially with
regard to the exchange of the target. The low cumulative dose received exemplified the close
collaboration evident in the technical teams.
Enrico Chiaveri – in his final INTC meeting – thanks the INTC for their support and also encouraged
the continuing collaboration between nTOF and ISOLDE which has been productive in the past and has
much promise in the future.
INTC 63 minutes Page | 4
Discussion and recommendations for the status reports presented at the open
session
INTC-SR-095 IS626 Status report: Radiotracer diffusion of copper and potassium in Cu(In,Ga)Se2 thin-film solar cells (4.5 shifts
remaining)
This experiment aimed at studying the diffusion processes in Cu(InGa)Se2 CIGS thin films which is a
promising material for low-cost/reasonable-efficiency solar cells. The authors intended to measure
copper self-diffusion (64Cu/67Cu) and the potassium impurity diffusion by radiotracer diffusion. Self-
diffusion measurements will give valuable information on defects and structure of the thin films. Alkali
metal doping was shown to improve PV performance.
Initial runs were hampered by the lack of good quality CIGS samples and the scheduled shifts were
instead used for Cu diffusion in high entropy materials. The original team who were interested in these
experiments no longer exists and there is insufficient manpower to continue this project. Considering
this, the committee recommend that the shifts are not retained after LS2.
The INTC recommends that the 4.5 shifts are not retained after LS2.
INTC-SR-096 IS627 Status report: Radiotracer diffusion in refractory high-entropy alloys (11 shifts remaining)
Measurements of diffusion mechanisms in the high entropy alloy AlScTiZrHf using radiotracer
diffusion of 46Sc. High entropy alloys, alloys with 5 or more principal elements, are expected to have
improved mechanical or electrical properties and decreased (sluggish) diffusion. In fact, diffusion is
important to understand materials properties such as creep for high temperature applications and
evaluate their kinetic stability against phase decomposition.
In a first run 6 samples were implanted with 47Sc in one shift. Measurements were not successful due
to oxidation of the samples during annealing at the ISOLDE set-up. This is why the proposers ask to
implant the 46Sc isotope for shipment and measurements at the home institution. This would furthermore
allow co-diffusion of 44Ti and 89Zr.
The case for continuing these studies was well made at the open session and the committee find the
proposed research still valid.
The committee took note that the physics case and original aim of the presented letter of intent
is still valid and timely. The outstanding 11 shifts should be retained for the duration of run3.
INTC-SR-097 IS543 Status report: Measurement of the 44Ti(alpha,p)47V reaction cross section, of relevance to gamma-ray observation of
core collapse supernovae, using reclaimed 44Ti (42 shifts remaining)
The 44Ti(,p)47V reaction is responsible for the 44Ti destruction in supernovae, thus the final amount of 44Ti in supernovae depends upon the reaction rate of this reaction. Previous measurements of this cross-
section are above the astrophysical relevant energy region (Ecm>6 MeV); the proponents aim at
extending the measure of this reaction in an energy region included in the Gamow region (4<Ecm<5
MeV).
The 44Ti(p)47V was measured at REX-ISOLDE in 2012. The 44Ti beam intensity on target ranged
from 5x105 to 2x106 pps, a factor about 10 smaller than expected. Moreover, only 10 shifts were
allocated. No protons coming from the 44Ti(,p) reaction were observed and only upper limits to the
cross-section were determined. After the addendum, the total number of shifts available is 42. The
INTC 63 minutes Page | 5
committee deem that the science case is very strong to measure this reaction energies relevant for
astrophysics. However, there are technical issues which the collaboration needs to be aware of.
The beam tests performed so far indicates that an intensity of 1e7 pps on target can be reached, but
fluctuations in the beam intensity are possible. A sample of 50 MBq of 44Ti is still available for
producing the beam. The precise number of shifts which may be possible is difficult to guarantee and
42 may not be achievable. The collaboration will need to adapt their programme depending on the yield
of the beam. However, the physics motivation for this experiment is still highly relevant and the
experiment is feasible with a beam intensity of 1e7 pps.
The committee took note that the physics case and original aim of the experiment is still valid
and timely. The outstanding 42 shifts should be retained for the duration of run3.
INTC-SR-098 LOI 171 Status report: Status report for the CRIS collaboration (13 shifts remaining)
The CRIS collaboration present a short summary of an impressive campaign of experiments in the
recent running period, with one, LoI171 which has shifts remaining. The status report highlights several
technical advances enabling a rich scientific program. Ground state spins and magnetic moments of K
isotopes up to N=33 have crossed the proposed N=32 magic number for the first time. The study of
copper isotopes has been extended to 78Cu, and the charge radii have recently been accepted for a Nature
Physics. A long series of isotopes in the Sn and In chains have been measured, with the latter extending
between almost two shell closures. In a pioneering experiment, the first laser spectroscopy measurement
has been performed on a short-lived radioactive molecule, RaF, submitted for publication to Nature.
The committee appreciated the summary of publications and PhD students.
LoI171: Towards laser spectroscopy of exotic fluorine isotopes
The physics motivation behind the status report for LoI171, originally submitted in 2016, is still valid.
The fluorine isotopic chain with a single valence proton beyond the Z=8 shell closure represents a rich
playground for a variety of state-of-the-art theoretical approaches. Measurements of changes in mean-
square charge radii, spins and moments are proposed with the data expected to contribute as a probe for
the emergence of shell structure, the role of many-body currents as well as continuum effects in the
nuclear many-body problem. The status report also presents more recent developments in quantum
Monte Carlo methods, with calculations of the ground-state electromagnetic properties of fluorine
isotopes underway.
The experimental challenges as discussed in the original LoI remain as recognized by the committee.
Although three working plans were originally put forward as a means of tackling a number of
outstanding questions, it is clear that the use of negative ions will not be available until 2022 and
therefore the collaboration, along with the COLLAPS collaboration, are recommended to focus on the
use of positively-charged ions. The allocated 7 shifts of radioactive beam time and 6 shifts of stable
beams requested are retained.
The committee took note that the physics case and original aim of the presented letter of intent
is still valid and timely. The outstanding 13 shifts should be retained for the duration of run3.
INTC-SR-099 IS556 Status Report: Spectroscopy of low-lying single-particle states in 81Zn populated in the 80Zn(d,p) reaction (36 shifts
remaining)
The goal of the experiment is to obtain information on single-neutron states above the N=50 gap in 78Ni,
in particular on the ordering and energy of d5/2 and s1/2, and d3/2 orbitals. As transfer reactions on 78Ni itself are presently not feasible, the next best case to establish single-neutron energies is the reaction 80Zn(d,p)81Zn. Systematics of the heavier N=51 isotones and theoretical calculations predict a d5/2
ground state, and a decrease of the s1/2 orbital, forming a low-lying excited state in 81Zn. The transfer
INTC 63 minutes Page | 6
reaction is expected to populate these single-neutron states and various other states based on their
coupling to the 80Zn core. The measurement of particle-gamma coincidences will give information on
the energies of the states. Proton angular distributions will give information on the angular momentum
transfer and should provide relative spectroscopic factors. The collaboration has previously performed
a successful experiment using the reaction 78Zn(d,p)79Zn.
The region around 78Ni has been extensively studied since the original proposal was submitted in 2012,
including gamma-ray spectroscopy of 78Ni, 79Cu, and 81-84Zn at RIKEN. However, the RIKEN
experiments using (p,2p) reactions probed mostly the proton orbitals and their role on low-lying
excitations, and are therefore highly complementary. The physics case for the (d,p) reaction is therefore
still valid.
The proposal assumes a five-fold increase in beam intensity due to the use of a new neutron converter,
positioned in the centre of a UCx target. The scheduling was delayed to await testing of this new
converter. There remains some doubt about the optimal target configuration, as the new converter in its
present design is incompatible with a quartz transfer line, which would suppress contaminants. It is also
not clear if the high beam intensity that is assumed in the proposal could be maintained over a long run.
Without an increase in beam intensity beyond what has been achieved earlier, it is questionable if
definite measurements of proton angular distributions and spectroscopic factors are feasible. However,
gamma spectroscopy gated on the proton ejectiles can be expected to yield important new information
on the neutron states even in the case of lower beam intensity. There is also a certain risk that the 1/2+
state remains undetected if it has a very low energy, and consequently a long lifetime, although
theoretical calculations predict that this is not the case.
In conclusion, the physics case is still valid, and despite some uncertainty about the beam intensity that
can be achieved, the measurement is expected to give important new results. ISOLDE is the only facility
in the world where such a measurement is feasible. The committee recommend that the 36 shifts
allocated to the experiment should be retained. However, the collaboration is recommended to
investigate in detail whether this is the optimal energy for observation of the ejected protons. Given
the time that the collaboration has been waiting for this beam, the experiment should be performed
during run3 and the collaboration should therefore assume the risk in terms of the yield for 80Zn. The
ISOLDE target team will consult closely with the collaboration so that the optimal strategy can be found
to deliver as reliably as possible the required beam.
The committee took note that the physics case and original aim of the presented experiment is
still valid and timely. The outstanding 36 shifts should be retained for the duration of run3.
INTC-SR-100 IS602 Status report: Cu(I), Ag(I), Cd(II), Hg(II), and Pb(II) binding to biomolecules studied by Perturbed Angular
Correlation of γγ-rays (PAC) spectroscopy (9.5 shifts remaining)
The project addresses a variety of questions concerning the function of metal ions in natural systems as
well as in synthetic biomolecules, and the toxic effect of some metal ions. For that, they employ the
technique of Perturbed Angular Correlation of γ-rays (PAC) spectroscopy.
The status report shows remarkable progresses in several lines of the project, in particular, those related
to the 199mHg PAC spectroscopy. They report however problems concerning the 68mCu and 111Ag
isotopes, so the sub-projects related to them have been discontinued. Because of that, the proponents
plan to focus on 111mCd, 199mHg, and 204mPb measurements for the remaining 9.5 shifts.
The status report mentions the strategy for these remaining shifts, which involves some research lines
not included in the original proposal. This raises concerns on whether these new projects should be part
of a new proposal. After the discussion of the INTC in the closed session it seems there is a general
INTC 63 minutes Page | 7
consensus that the distribution of shifts should not be strict1 and hence some flexibility should be
allowed, when reasonably justified. In the opinion of the committee, this is the case of the present
proposal, the recommendation is to keep the remaining 9.5 shifts.
The committee took note that the physics case and original aim of the presented experiment is
still valid and timely. The outstanding 9.5 shifts should be retained for the duration of run3.
INTC-SR-101 IS630 Status report: Lattice sites, charge and spin states of Fe in InxGa1−xN studied with emission Mössbauer spectroscopy
(4 shifts remaining)
The experiment aimed at measuring temperature- and angle-dependent eMs after 57Mn implantation to
investigate lattice location, charge and spin states of Fe in InxGa1-xN. The original proposal included
also rapid-cooling experiments and implantation with long-lived 57Co. These two last measurements
could not be performed for safety reasons and the current lack of a 57Co beam at ISOLDE.
Six out of the ten of the granted shifts have been already used. The results of the data analysis show a
decrease in the site population of magnetic contributions with increasing In concentration, as well as
the evolution of a single line component, the nature of which remains unclear. Using the 4 remaining
shifts the proponents aim at further investigating the single line component and identifying Fe on
different lattice sites and the effect of dopants in nitrides ternary semiconductors.
The work proposed is of interest although the committee had some caveats: There is known degradation
due to higher In content as such the collaboration are proposing to pre-implant with 29Si. It should be
remarked that it is difficult to create consistent samples with varying concentrations. The collaboration
are advised to characterise their samples as well as possible to know in advance to the online
experiments the structural properties of their samples. The collaboration are also advised to carefully
prioritise the final experiments to conclude the current programme and the committee look forward to
publications based on this work. In spite of some reservations, the committee recommend that the shifts
are maintained for run3.
The committee took note that the physics case and original aim of the presented experiment is
still valid and timely. The outstanding 4 shifts should be retained for the duration of run3.
INTC-SR-102 IS647 Status report: Local Probing of Ferroic and Multiferroic Compounds (4 shifts remaining)
This status report describes a large body of work on ferroic and multiferroic materials using local probe
PAC spectroscopy. PAC studies are ideally suited to investigate structural, charge, and orbital
correlations and their impact on the multiferroic behaviour. The PAC measurements are complemented
at the home laboratories by various other techniques, e.g. X-ray diffraction, TEM, SEM and so forth,
and by density functional theory calculations, all of which are essential tools for a conclusive
interpretation of the PAC measurements. The topic is scientifically highly interesting and relevant. With
many of the originally planned compounds measured, the group has already demonstrated that their
technique is a viable method for studying the connections between ferroelectricity and ferromagnetism
on multiferroics. The number of publications so far is high, with high impact publications submitted or
about to be submitted. The request for maintaining the 4 shifts of beam time in order to conclude works
almost completed and to proceed with studies initiated in 2018 is strongly supported by the committee.
The shifts are therefore maintained for run3.
The committee took note that the physics case and original aim of the presented experiment is
still valid and timely. The outstanding 4 shifts should be retained for the duration of run3.
1 See AOB, below.
INTC 63 minutes Page | 8
INTC-SR-103 IS564 Status report: Study of the unbound proton-rich nucleus 21Al with resonance elastic and inelastic scattering using an
active target (43 shifts remaining)
The experiment aims at investigating the low-lying structure of 21Al by measuring resonance elastic and
inelastic scattering 20Mg+p with an active target. The proposal was submitted in 2012 and the
experiment has yet not been performed. The experimental setup of the original proposal was the active
target MAYA, in the present status report the ACTAR TPC device will replace MAYA. It requires a
beam intensity of 50 pps.
The committee deemed that the science case was still valid and timely. However, this experiment has
also been proposed at TRIUMF, where a beam intensity of at least a factor of 10 higher than at HIE-
ISOLDE is possible. As was discussed during the open session, were this experiment to be accepted at
TRIUMF, the proponents declared that they would perform the experiment there. Given that the
proposal has just been accepted at TRIUMF, the INTC recommend that the proponents withdraw the
proposal from ISOLDE especially as this experiment is more feasible at TRIUMF.
The INTC recommends that the 43 shifts are not retained after LS2.
INTC-SR-105 IS583 Status report: Beta-NMR of copper isotopes in ionic liquids (18 shifts remaining)
This status report refers to a previously accepted proposal submitted to the INTC in 2013. In short, the
proposal centers on a feasibility test of spin-polarization and β-NMR studies on short-lived isotopes of
copper, specifically 58,74Cu. The underlying motivation for the studies is the importance of Cu as a metal
ion in various bio-systems. In order to understand protein functions it is necessary to elucidate the
structure and dynamics in the proximity of a metal binding site. β-NMR is sensitive to chemical shifts,
line broadening and relaxation times – providing information about energies and dynamics of chemical
bonding. Experiments performed in TRIUMF on 31Mg by the authors have shown the validity of this
method, which is now to be applied to the copper isotopes as proposed here for the VITO beamline.
The committee finds the scientific motivation to be very strong and of interest. It is noted that no similar
experiments have been carried out elsewhere and it is understood that the yields of the requested copper
isotopes are currently appropriate to ISOLDE. Nevertheless, it has been brought to the committee’s
attention that the current planning for activities during run3 at the VITO beamline involves many
different experiments and does not leave any possibility for realising the Cu studies. The VITO plans
are outlined in LoI-213 and the authors of LoI-213 have clarified that they do not intend to pursue
copper for biochemistry applications. In these circumstances the committee recommends that
experiment IS583 is closed.
The committee does however advise that the polarization of copper for biochemistry applications is not
pursued in a future proposal, unless all relevant parties on the original proposal are invited to join.
The INTC recommends that the 18 shifts are not retained after LS2.
INTC-SR-106 IS593 Status report: Implanted 7Be Targets For The Study of Neutron Interactions With 7Be : (The Primordial 7Li Problem)
(24 shifts remaining)
This proposal was accepted by the 47th meeting of the INTC held in June 2015. Astrophysical
observations of the primordial 7Li are about a factor of 3 off the prediction (the primordial 7Li problem).
The destruction of 7Be due to its interaction with neutrons would deplete the formation of 7Li and hence
this reaction is a promising candidate to explain the overestimation of the 7Li abundance. The proposal
aimed at producing a pure sample of 7Be via mass separation at ISOLDE that will be later used for the
INTC 63 minutes Page | 9
neutron beam provided by the “Soreq Applied Research Accelerator Facility” (SARAF) in Israel. The
goal is to measure the (n,p) and (n,alpha) reaction rates.
As was already recognized by the INTC, the physics case of this proposal is very appealing. As such,
the proposal was granted with 24 shifts. This approval was however subject to the availability of
SARAF. Presently, this facility is being upgraded to its phase II and it is unclear when it will become
operational again as well as the conditions under which it will operate. This makes it difficult to make
a realistic estimate of the required activity of the 7Be target.
Because of these reservations – although the science case is valid – it seems advisable to discontinue
this proposal until the situation regarding SARAF-II is clarified.
The INTC recommends that the 24 shifts are not retained after LS2.
Summary and recommendations for Letters of Intent reports which were
discussed during the closed session
The committee considered the letters of intent which have been received from collaborations wishing
to occupy space in the ISOLDE in the near to medium future. Although space within the hall is governed
by the ISOLDE collaboration, the proposed science cases are the domain of the INTC and additional
resources are to be approved by the Research Board.
Some questions on the management of the collaborations which have submitted letters of intent were
raised. The INTC recommend that the collaborations reach out to existing groups to synergise their
future plans; new setups should not be able to displace scientifically productive collaborations purely
by virtue of their novelty and/or financial resources.
Due to a lack of time, three of the submissions, in solid state physics – whose plans are in the more
medium future – were not considered at this meeting and will be discussed at the next INTC. The
committee expressed their appreciation for the influx of new ideas and physics among the solid state
collaborations. The relevant letters are I-208, I-211 and I-212.
INTC-I-208 Upgrade of the UHV-system ASPIC for the investigation of surfaces and two-
dimensional materials by ultra-low energy implantation and deposition of radioactive probe
atoms The discussion on I-208 was postponed until the 64th meeting of the INTC.
INTC-I-209 PUMA: antiproton Unstable Matter Annihilation This is an addendum to the already endorsed Letter of Intent and the Memorandum presented to the
INTC in February and June 2018, respectively. The current document confirms the intention to propose
experiments at ISOLDE with the PUMA apparatus when developed, with the goal to study the evolution
of neutron skins with isospin, as well as proton and neutron halos in exotic nuclei by use of trapped
antiprotons. The committee notes that the full proposal for PUMA was recently submitted to the SPSC.
It is anticipated that upon accepting this proposal by the SPSC the individual proposals for experiments
with PUMA at ISOLDE will be submitted to the INTC in 2021 with the aim at running these
measurements in 2022. The committee confirms its very positive attitude towards the PUMA project
and looks forward to the next stages of its development. The committee recommends that the ISOLDE
technical groups investigate how MIRACLS and PUMA can be accommodated without interfering with
existing productive setups e.g. Miniball and IDS.
INTC 63 minutes Page | 10
INTC-I-210 Upgrade and scientific programme of LUCRECIA, the Total Absorption
Spectrometer at ISOLDE LUCRETIA is a total absorption spectrometer (TAS) based on a large NaI crystal of 38cm diameter
and 38cm length. The instrument has been used successfully for 20 years at ISOLDE, and it has
produced several PhD theses and publications. Contrary to more modern TAS spectrometers,
LUCRETIA is not segmented. This is a disadvantage, as it cannot not provide information on gamma
multiplicity and individual cascades.
The Letter of Intent provides an extensive list of physics cases that the collaboration intends to
investigate with TAS spectroscopy in the coming years. The questions that are addressed in these cases
are in general interesting, and experiments with LUCRETIA can be expected to provide valuable
information. The collaboration is presently refurbishing the tape system. As space around the beam line
is very limited, the impact on other experiments should be considered and needs to be discussed
carefully within the ISOLDE collaboration.
The collaboration should prioritize the cases where TAS spectroscopy can provide significant new
insight into the underlying physics questions. They should also focus on experiments that are unique to
ISOLDE and which cannot be investigated elsewhere. With the call for low energy proposals in June,
Lucretia are recommended to submit their strongest science cases as proposals which will benefit
from these proposed upgrades.
INTC-I-211 eMMA - Development of an emission Mossbauer apparatus at ISOLDE for the
investigation of magnetic materials
The discussion on I-211 was postponed until the 64th meeting of the INTC.
INTC-I-212 MULTIPAC-Setup for gamma-gamma Perturbed Angular Correlation
Experiments in Multiferroic (and Magnetic) Materials
The discussion on I-212 was postponed until the 64th meeting of the INTC.
INTC-I-213 Research plans for the laser-polarization beamline VITO at ISOLDE The letter presents future research plans for the VITO beamline at ISOLDE. This is truly a multi-
disciplinary proposal ranging from biophysics to nuclear structure. The LOI is concerned with an
upgrade of the existing laser-polarization beamline for radioactive nuclei VITO. The main goals are to
measure biological beta-detected NMR and beta-decay asymmetry. The future program is proposed to
include additionally (i) the determination of spins of the nuclear excited states by the measurements of
the beta-gamma-neutron correlations, (ii) the measurement of the electromagnetic nuclear moments and
the condensed matter studies using beta-detected NMR.
The proposed upgrades, which will increase the footprint of VITO, are as follows: (i) implementing a
superconducting magnet for fields up to 4.7 T in addition to the current electromagnet reaching 1.2 T
(ii) improvement of the differential pumping allowing the maintenance of the liquid samples at high
pressure (iii) implementing the compact magnet with combined beta, gamma and neutron detectors, (iv)
implementing a reionization cell (to ionize polarized atoms) allowing the deflection of ions to different
experimental stations (v) implementing switchyard.
The proposed improved VITO beamline is indeed very versatile and interesting. It will allow, with a
high sensitivity of beta-NMR, to address the problems related to the electronic/chemical environment
of metal ions in biologically relevant materials or the modification of the bulk properties in systems
with reduced dimensionality. From the nuclear physics point of view, (i) the high precision
measurements of electromagnetic nuclear moments, (ii) the determination of the spin of the excited
INTC 63 minutes Page | 11
states populated in beta-decay and (iii) the high precision measurements of beta-decay asymmetry are
very attractive and important.
The committee endorses the proposed science case which was found to be innovative and wide-ranging.
The committee notes however that space is at a premium in the area of the hall where the proposed
upgrades should take place and the feasibility of these needs to be shown.
INTC-I-214 The SpecMAT active target SpecMAT is an active target based on a TPC that is combined with a compact array of CeBr3
scintillation detectors, to be used inside the ISS solenoid. Transfer reactions with RIB in inverse
kinematics suffer from two problems: low statistics due to low beam intensities, and poor energy
resolution due to the inverse kinematics. SpecMAT tries to overcome both: the use of an active target
leads to much higher luminosity compared to thin polyethylene targets. Placing the TPC into the strong
magnetic field of ISS allows determining the particle energy with high precision from the curved tracks.
The combination with gamma detectors gives even better energy resolution and makes the setup unique
in the world.
There is no doubt that SpecMAT has high scientific potential and will be a big asset for ISOLDE. Due
to the high luminosity and resolution, it will allow performing experiments that are not feasible with
the Miniball/T-Rex setup, or other similar setups elsewhere. The project has seen a delay of
approximately 9 month compared to the original schedule, but the performance of the components
seems to be very satisfactory. Installation at ISOLDE is planned for early 2020. Tests with stable beams
later in 2020 would be beneficial for the project.
The Letter of Intent mentions three physics cases, namely the shell structure around 78Ni, shape
coexistence in the neutron-deficient Hg and Pb region, and pygmy dipole resonances in neutron-rich
nuclei. It can be expected that experiments with SpecMAT will contribute important new results in
these areas. The instrument offers unique opportunities to contribute in an important way also to other
physics cases. It will without doubt be very attractive for a wider user community, and is in general a
very valuable addition to the ISOLDE infrastructure. The committee take note of the progress and look
forward to its implementation at ISOLDE.
INTC-I-215 MIRACLS – the Multi Ion Reflection Apparatus for Collinear Laser
Spectroscopy of radionuclides This addendum to the originally accepted Letter of Intent and Memorandum for the MIRACLS project
provides an update on the required resources in terms of space in the ISOLDE hall, electrical power,
testing of equipment and so forth. The committee have already favourably reviewed the project and
took note of the request at the time for stable beam testing during the long shutdown of ISOLDE, as
required by the collaboration in connection with the ERC funding period. The committee focused
therefore on the space requirements put forward in the addendum. These will need further discussion
as the layout is considerably larger than originally foreseen. The committee suggests that the
collaboration look at ways to minimize the space as currently presented.
However, the committee strongly supports the request that stable beam be provided during this period,
as originally requested, and suggests that the collaboration focuses on meeting the immediate
deliverables set out in the ERC project before discussing a longer-term perspective which will be
influenced by the current space within the ISOLDE hall.
AOB: The INTC chair has received a request from the ISOLDE solid state community to allow more flexibility
in the choice of isotopes for proposals where the strict allocation of shifts per isotope can be reduced;
INTC 63 minutes Page | 12
rather a choice of isotopes within an allocated number of shifts is being sought which would allow more
flexibility for scheduling. This would allow these experiments to adapt to the ISOLDE schedule and
would permit such experiments to run more frequently: important as the time scale for impact within
solid state and materials physics is considerably shorter than other areas. The committee recommended
this approach – assuming that a strong science case is made – for the forthcoming proposals for run3
and also applied the rationale to the above-discussed status report, SR-100.
The openness of CERN proposals and presentations was discussed. The INTC is committed to
upholding CERN’s policy of openness of submitted proposals. Future calls for proposals will remind
proponents that documents will be publicly visible on the CERN website and collaborations are
expected to respect this and to adapt their proposals and figures so that potentially sensitive information
is not compromised within this policy.
Enrico Chiaveri – in his final meeting as nTOF spokesperson – thanked the committee for all its support
during his tenure. The committee in turn thanked Enrico for his contributions to the INTC and nTOF
over the years.
As this was also his last meeting as INTC Chair, Karsten Riisager thanked all the members of the INTC
for their efforts during his time in this position. On behalf of the ISOLDE Collaboration, Gerda Neyens
warmly thanked the outgoing chair for his contribution over the past years. The new chair of the INTC
will be Marek Pfutzner.
Low energy proposals will be accepted once again for the June 2020 meeting: the deadline for
submission will be 6 weeks before the open session.
The dates of the next meetings will be 24th and 25th June (Wednesday/Thursday) and on 3-4 November
(NOTE: Tuesday/Wednesday).
The meeting was then closed.
Minutes taken by Karl Johnston
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