collaboration with medical and biology centers of the Caen region. In addition to the direct production of 211At, the collaboration wants to investigate the production of a ²¹¹Rn generator that will decay to ²¹¹At. This may be a way to allow distribution in a larger area and therefore easier exploitation. The installation of a high-power target in a dedicated zone in the LHE will allow to efficiently carry on this research plan without interfering with other experiments foreseen in the SPIRAL2 building.

The context of the REPARE project follows a worldwide increasing interest for targeted radionuclide therapy (TRT) which has proven to be particularly effective to treat specific kinds of cancer which resist conventional therapies, minimizing the collateral effects. Among TRT, TAT is a modality that is of great potential thanks to the high linear energy transfer of alpha particles and their high relative biological effectiveness. Only few alpha emitters can be used for TAT among which are ²²⁵Ac and ²¹¹At, which can be produced using accelerators. Alpha or 7Li beams, as provided by the SPIRAL2 accelerator, are necessary to produce ²¹¹At directly or through ²¹¹Rn. Thanks to the availability of an intense alpha (7Li) beam, only few hours of beam time will be needed to obtain the activity necessary for a patient dose to perform clinical trials.

A budget of 1.116 M€ has been estimated to build the new beam line, plus 221 k€ for the new casemate. The PI intends to apply to funding agencies to finance this construction, and requests that GANIL grants scientific support, a dedicated space in the LHE, manpower and beam at the rate of 4 hours per week to the project.

The SC thinks that GANIL will benefit from such a research program with very high potential societal impact and great interest from the local government. Furthermore, this program fits very well with the activity assigned for GANIL (more specifically, the development of innovative techniques for hadron therapy and radiobiology) and is recommended in the report of the "Spiro committee" for the future of GANIL.

At the GANIL level, the construction of a third hall in the SPIRAL2 building may be an opportunity also for other experiments because it will allow for the possibility to switch more quickly from one experiment to another and make more efficient use of the beam time. The SC suggests that the design of the new beam line needs to be optimized to minimize the costs. It also points out that a special care on radioprotection is needed as it is a non-conventional activity on the GANIL site temporarily producing a high level of radioactivity around the target station.

To be able to play a role in medical research, one production run per week (preferably at the beginning of the week to let people have time for follow-up mice or patient procedures) is mandatory.

It is important that this project not impact the other main projects of GANIL (S³, DESIR and NEWGAIN). For this reason, after the R&D phase is concluded, the radioisotope production has to be handed to industrial companies. The goal of GANIL and the consortium around this project is the study of new production methods and the validation of the full chain up to clinical trials. In this sense, the SC recommends that the collaboration work towards a portfolio of new radioisotope studies beyond 211At that may benefit from the specificity of this new installation in the SPIRAL2 facility.

* The SC recommends that an MOU is needed to organize the collaboration among GANIL and medical and biology centers of the Caen region and to clearly identify commitments of its members. Clear identification of needed investment is mandatory for GANIL and others for partners that will take care of the chemistry, radiobiology and radiolabeling as well as preserving the option to move GANIL to SPIRAL2 Phase 2 as recommended in the recent report on GANIL's future.

## MIRRPLA (Multiple-beam IRRadiation PLAtform to investigate the origin of organic matter) project

MIRRPLA is part of the PEPR Origins, from planets to life – technological, societal and epistemic breakthroughs, with a budget of 45.5 million euros over 7 years. It is included in a Work Package of the axis 4, on the emergence of life. MIRRPLA is already funded (equipment of about 800 k€ and personnel costs around 270 k€). The scientific value of the project has also been evaluated positively in the framework of this accepted PEPR Origins.
The MIRRPLA platform consists of a unique ultrahigh vacuum chamber, combining three types of irradiation sources (UV photons, keV electrons and keV-GeV ions), equipped with in situ

infrared and mass spectrometers. This device meets the challenge of the PEPR to build the most efficient and
appropriate tools to understand the complex mechanisms at the origin of life.

The selected ionizing beams, including those of GANIL available in a wide range of particle type and energy, are very relevant to simulate the processes that occur in space such as the solar wind and cosmic rays. These ionizing radiations will be used independently or in combination. For the first time it will be possible to study potential synergistic effects, where there is no data yet. It is very interesting to mention the possibility to irradiate with heavy ions, which, even if they are a minority in space compared to electrons and photons, have a great impact on the behavior of space matter, either organic or inorganic.

This field of research has been very active in GANIL for several years. The beginning of this project is linked to the work on polymers carried out at CIMAP for many years, which gradually led to the design of this very original device. The PEPR origins provides an excellent opportunity for the CIMAP teams to benefit from the skills and expertise acquired in this field to upgrade experiment capabilities in this research field with the MIRRPLA Platform. This expertise will be complemented by the collaboration of the PIIM laboratory, partner of the PEPR Origins, expert in photon and electron irradiations.

The field of investigation is huge and complex. The first experiments will use 1 µm thick ice samples made of simple carbonaceous molecules, to simulate icy mantles. The targets will be progressively made more complex.

The committee wishes to emphasize the unique character of this new setup which should make GANIL highly attractive for the astrophysics community and to new external collaborations. The platform will be open to the whole scientific community via GANIL-CIMAP-CIRIL user's facility. This project will certainly contribute to the international visibility of GANIL and CIMAP.

Recommendations

It is planned to install this platform in the D2 room of GANIL. This room is currently cluttered and it will be necessary to clear it, make it clean and equip it to receive this new equipment. The workforce and budget requirements on the part of GANIL to allow this installation in D2 seem to be minimal. However, technical adaptations necessary to install MIRRPLA in the D2 room need to be further specified and quantified. The effort from GANIL for the platform installation in the D2 room needs to be estimated.

NEW JEDI

The main goal of the NEW JEDI project is to find a signal verifying the existence of a light X boson with a mass of 17 MeV that has been hypothesized from recent measurements of 8Be decay. Studies planned to be carried out at GANIL and iThemba LABS were triggered by the experimental observations reported in a Physical Review Letters article by A. Krasznahorkay (so-called ATOMKI ANOMALY). Although this is a high-risk project, signal confirmation, which would indicate physics beyond the standard model, will be crucial for all modern physics.

The project's current state is in the data analysis phase, and the results will be reported in 2023. There are three possible outcomes of the analysis:

(1) **The reported effect is confirmed.** Since the detection setup is different from that of ATOMKI ANOMALY, this would be an independent confirmation that would exclude uncertainties connected to the original experimental approach. In such a case, a new physics field would experience a boom and strong competition would start. It will be a meaningful confirmation (not a discovery) of the existence of a particle beyond the standard model; it seems natural to continue supporting and investing in the project, as with the beams, detectors, and workforce involved are already available, GANIL would be in a favorable position for the competition.
(2) The reported effect is not confirmed by a significant factor. If the collected data allows rejection of the announced effect, the collaboration publishes the negative results, adds a new exclusion zone to the systematics, and further investigations should conform to GANIL and PAC standard rules.

(3) The experimental result is inconclusive. In the case of a measurement that is not definitive, it should be clarified by the collaboration whether this situation is under control, given the amount of accumulated data (500 expected X-bosons/week, four weeks of data), the expected statistical error, and the statistical significance of the original claim as well as the possibility that nuclear structure effects may lead to this situation.

The SC had several observations on this effort during the meeting:

* The ratio of the possible profit, i.e., finding a light boson (the first BSM signal) - a new interaction, to the effort involved (people, even if they are not too young, money, etc...) is very favorable. We note the possible scientific profit with possible outcomes: positive: triggers all community to pursue X17; negative: new exclusion zone, further search needs reconsiderations.

* It is not clear how the project is situated among the competition. Other experimental efforts were mentioned but few details were provided.

* The decision to support the next beam campaign should be taken after the knowledge of the analysis of current results is obtained.

* The necessity and reasoning for measurements of other light systems was briefly mentioned in the presentation (J.L. Feng et al., Phys. Rev. D 102 (2021) 036016.) The plan for potential future experiments should be prepared by the collaboration that allows for changes in direction based on an informed decision from analysis of previous measurements.

* Questions on workforce issues and long term experimental support were touched upon in the presentation. While this is a rather internal organizational issue, it is possible to look for a synergy in other GANIL projects such as remote experiment control.

Ending the support for this project now might result in a loss of one year amid a very competitive environment that can be expected in the case the effect is confirmed. Realizing this, the SC recommends to continue the support for the project with respect to the following points:

* The collaboration maintains a reasonable material/financial demand;

* Workforce (students) requirements that are justified (also in the case of negative outcome of the analysis);

* The experimental equipment obtained during the project remains in GANIL

If a positive result is found for X17, the SC recommends that the collaboration **define the strategy** for the follow-up experiment(s), since GANIL may find itself in a unique position in this potentially new branch of research due to its intensive stable beams available from the LINAC, an existing, fine-tuned and tested detector system accompanied by simulation and analysis codes, and a local and international team, that has acquired the necessary experience to carry out this research.

The project has lost a key senior co-spokesperson(s) due to his retirement. GANIL may consider creating a position for a temporary/partial involvement of this person with a plan to transfer his knowledge to a young team member(s).

## S³ Commissioning

The S³ spectrometer is a flagship facility of GANIL that will bring unique science capabilities at GANIL for stopped beam physics, such as laser spectroscopy and mass measurements as well as for super-heavy element research. S³ will have the combined advantage of high-resolution laser spectroscopy, Mr-ToF-MS (PILGRIM) and a high-performance alpha and conversion electron decay detector (SEASON) for the study of the ground and isomeric states of nuclei along the N=Z line and of heavy refractory elements, heavy actinides and super heavy elements. Laser spectroscopy and mass measurements of neutron deficient nuclei, especially in the vicinity of ¹⁰⁰Sn has the potential of strong scientific impact. The absence of ⁴⁸Ca beam impacts the SIRIUS experimental program, therefore the first phase science program needs to be reconsidered.
There are two detector configurations in the focal plane, the SIRIUS detector setup used mainly for heavy element decay studies and LEB for laser spectroscopy and mass measurements. The committee appreciates the SWOT analysis that was presented.

The committee has the following recommendations:

* We recommend that GANIL management prioritize a rapid commissioning of the S³ spectrometer.

* We recommend that the S³ scientific collaboration work out a plan for first exploratory physics runs simultaneously while commissioning the spectrometer and the focal plane detectors. The physics cases to be studied during commissioning should evolve through a consensus from the collaboration and should be factored into the time allotted for S³ commissioning.

* In particular, physics cases that are easily feasible from already demonstrated beams should be chosen. A list of three possible LEB experiments during commissioning was presented. The physics outcome from each needs to be specifically reviewed for international competitiveness. This was not clearly presented. One experiment each with <sup>40</sup>Ar and <sup>50</sup>Cr beams could be planned. Although the latter is expensive the structure information around <sup>100</sup>Sn will be of high scientific value.

* It was not clear if the possible commissioning experiments with SIRIUS were only to verify published results or if they will also have the potential for some new physics information, too. It is recommended that the collaboration work out a strategy for first experiments. The <sup>22</sup>Ne+Pt -> <sup>216-220</sup>Ra -> <sup>210-214</sup>Ra has a large cross section, hence might be a simpler case to start with if sufficient new physics information can be derived.

* The standalone cryogenic plants and the cryogenic distribution lines need to be fully tested and should be very robust and trouble-free. This aspect needs to be simultaneously ensured, as stable cryogenics is critical for the operation of the spectrometer as a whole and can more often than not, derail the schedule during the commissioning phase.
<figure><img src="image_193.png" /><figcaption>IV.ORGANISATION CHART</figcaption></figure>
<figure><img src="image_194.png" /></figure>

GANIL

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TEL. 02 31 45 46 47 - https://www.ganil-spiral2.eu/fr/

Directrice de la publication : Patricia Chomaz

Directrice de la rédaction : Fanny Farget

Conception graphique : Stéphanie Pupin

Coordination éditoriale : Stéphanie Pupin et Magali Tencé