GENESIS Facility Personnel

  • M. BAYLAC, Research engineer
  • A. BILLEBAUD, Director of Research, Scientific coordination 
  • B. CHEYMOL, Research engineer, Executive director
  • E. LABUSSIERE, Engineer
  • S. REY, Engineer
  • T. CABANEL, Assistant engineer

GEnerator of NEutrons for Science and IrradiationS

GENEPI2 small

Crédits S.Maurin 2017

The facility evolution

Built in 2003 under the name "PEREN" for the needs of the LPSC reactor physics group, the facility was dedicated to nuclear data experiments required for inovative nuclear reactor research. It consisted at the beginning in the coupling of the pulsed neutron generator GENEPI2 (designed and built by the Acelerator group of LPSC) to a lead slowing-down time spectrometer, replaced later by graphite and Teflon massive blocks.

Since 2014 the facility went through several upgrades, among which the change for a continuous source is a major one. If offers now a higher beam intensity range and a better reliability. It hosts regularly private companies needing fast neutron for irradiations.

In 2016 the facility joined the IRT (Institut de Recherche Technologique) Nanoélec program.

At the end of  2017 the facility became the GENESIS facility, and is one of the 7 IN2P3 official research platforms.

The facility

schema GE2 us

The neutron source is provided by the GENEPI 2 electrostatic accelerator : it can deliver 220 keV deuterons, analyzed by a magnet and guided onto a deutered or tritiated target. Subsequent D(d,n)3He or T(d,n)4He reactions produce fast neutrons of 3.1 MeV or 15.2 MeV respectively (at 0° for 220 keV incident neutrons). The deuteron source is a continuous source (ECR compact source), allowing the creation of deuteron beams in the intensity range from 10 μA to 1 mA. Some typical present neutron productions are summed-up in the table below.

Continuous Source

En (0°)

Neutron source  max intensity (4π)

Neutron Flux at 1 cm, 0°

Tritium Target

15.19 MeV

~8x109 n/s

5x107 n.cm-2.s-1

Deuterium Target

3.09 MeV

(characterization in progress)

qq 105 n.cm-2.s-1

ddg GE2

To use the facility

The facility can accomodate on request experiments - from public or private laboratories - requiring fast neutrons with specifications as described above. The neutron source can used alone (empty room) or with moderators. The monitoring of the neutron source is ensured by the detection of charged particles associated to the neutron production.

The user schedule is defined over a period of 6 months, any application should be sent to the This email address is being protected from spambots. You need JavaScript enabled to view it..

The running rate, depending on your organisation, can be provided on request.

Facility managers : Benjamin Cheymol, Accelerator Group,+33 (0)4 76 28 45 05

Scientific coordinator : Annick Billebaud, Reactor Physics Group, +33 (0)4 76 28 40 57

Technical team : Solenne Rey, Accelerator Group, +33 (0)4 76 28 45 92

Thesis in preparation

  • Études des déflecteurs électrostatiques sur faisceaux de hadrons polarisés pour JEDI, par Julien MICHAUD, directeur : JM De Conto, depuis octobre 2016
  • Études de l’efficacité de conversion de vapeurs métalliques des ions multichargés en sources ECR, par Alexandre LEDUC, thèse en co-tutelle GANIL-LPSC, directeur : L. Maunoury (GANIL), co-directeur : T. Thuillier, depuis octobre 2016
  • Investigation of Plasma Kinetic Instabilities in ECR Ion Sources, par Bichu BHASKAR, thèse en co-tutelle UGA-JYFL, directeur (JYFL) : H. Koivisto, co-directeur (UGA) : T. Thuillier, depuis décembre 2017
  • Machine learning appliqué aux accélérateurs, thèse CIFRE, directeur : JM De Conto, co-directeur: F. Bouly, depuis février 2018

2016-2018

Accélérateur linéaire pour le projet MYRRHA

Projet R&D Multipactor

  • D. Amorim et al., Design of a RF Device to Study the Multipactor Phenomenon, 7th International Particle Accelerator Conference, May 2016, Busan, South Korea, 2016

Projet JEDI

  • Frank Rathmann et al: The search for electric dipole moments of light ions in storage rings
    2013 J. Phys.: Conf. Ser. 447 012011
  • D. Eversmann et al : New Method for a Continuous Determination of the Spin Tune in Storage Rings and Implications for Precision Experiments - Phys. Rev. Lett. 115, 094801 (2015)
  • G. Guidoboni et al: How to Reach a Thousand-Second in-Plane Polarization
  • Lifetime with 0.97-GeV=c Deuterons in a Storage Ring - Phys. Lett. 117, 054801 (2016)

Booster de charge

  • Diagnostics of a charge breeder electron cyclotron resonance ion source helium plasma with the injection of 23Na1+ ions, O. Tarvainen, H. Koivisto, A. Galata, J. Angot, T. Lamy, T. Thuillier et al., Physical review accelerators and beams19, 053402 (2016).
  • Plasma instabilities of a charge breeder ECRIS, O. Tarvainen, J. Angot, I. Izotov, V. Skalyga, H. Koivisto, T. Thuillier, T. Kalvas and T. Lamy, Plasma Sources Sci. 26, 105002 (2017).
  • Charge breeding time investigations of electron cyclotron resonance charge breeders, Julien Angot et al., Phys. Accel. Beams 21, 104801 (2018)

Within the straight continuity of the undertaken work on GUINEVERE – a demonstrator dedicated to feasibility studies on hybrid reactors technologies (deuteron beam: 250 W, reactor: 150W) - LPSC is involved in the MYRRHA (Multipurpose hYbrid Research Reactor for Hightech Applications) project.

Supported by the  SCK-CEN, the MYRRHA project aims at the construction of an ADS (Accelerator Driven System) demonstrator (50 to 100 MWth) in order to study the feasibility of high radiotoxicity nuclear wastes. The nuclear reaction, in the subcritical core of this fast spectrum reactor, will be sustained thanks to spallation neutrons. These neutrons will be produced by means of a proton beam impacting a target: a Lead-Bismuth eutectic. 

A high power accelerator will produce a continuous wave (CW) proton beam (4 mA – 600 MeV). In addition to the high beam power, one has to consider that frequently-repeated beam interruptions can induce high thermal stresses and fatigue on the reactor structures, the target or the fuel elements, with possible significant damages especially on the fuel claddings. Therefore the accelerator will have to be extremely reliable. The present tentative limit for the number of allowable beam trips is: 10 unexpected interruptions longer than 3 seconds per 3-months operation cycle. The reference solution for the accelerator (studied in the MAX project) is a superconducting accelerator with a fault tolerant scheme for rapid RF failure mitigation. To maximize the reliability this accelerator design is based on a redundant injection line. The superconducting line will be composed of one family of spoke cavities and two families of 5-cells elliptical cavities.In the 1st step of the R&D programme dedicated to this multi-megawatt demonstrator, the LPSC construct, implement and test a prototype of the Low Energy Beam Transfer line (LEBT) of the proton injector (10 mA, 30 keV).  The LEBT main goal is to produce and shape the proton beam for its proper injection in the RFQ (Radiofrequency Quadrupole). To maximise the accelerator reliability and the beam availability, the LEBT design is based on a compact line with a minimum of electrostatic element. It is composed of an industrial ion source,  combined magnetic elements (solenoids + steerers) for the beam focussing, beam diagnostics, a fast chopper, a beam dump as well as pumping system for the residual gas regulation in the line and a global control system. The mechanical construction of the LEBT is now in progress:

  • The magnetic elements are under construction,
  • The beam dump design is achieved with thermal simulation,
  • A system of 4 independent slits is defined; it will enable  to tune the transvers profile of the beam,
  • Beam diagnostics will enable to measure the profile and the emittances in both transverse directions.

LEBT MYRRHA 3D

A view of the LEBT: from the source to second solenoid.

The SCK-CEN is responsible for the chopper design and its construction. The global control system is developed by a private company in partnership with SCK-CEN and the LPSC. An experimental area was implemented to welcome the LEBT at LPSC.  It will fully be characterised at Grenoble before being sent to Belgium for its coupling with the RFQ.

 

beam enveloppe

 Beam simulation in the LEBT with a space charge compensation of about 80%. Beam envelope in the horizontal plan.

 

The understanding of high intensity beam dynamics at low energy is a key point to enable its good transports through the LEBT. In this energy range, the beam physics is dominated by non-linear effects due to the space charge field induce by the beam on itself. This field has defocussing effect on the beam, which induce a halo growth. However, the beam can also ionise the residual gas inside the line, with the consequence of creating ion/electron pairs. These generated secondary particles can either be trapped or repelled by the proton beam; depending on their charge. Particles with an opposite charge to the beam (in our case electrons for the proton beam) will gathered inside the beam potential well which can therefore be considered as a kind of plasma. The beam defocussing, due to the proton/proton repulsive effect, can therefore be minimised.

influence SCC

 Illustration of the space charge compensation effect at the LEBT output. Left: the emittance in the horizontal plan and the transverse beam profile assuming there is no space charge compensation. Right: the emittance in the horizontal plan and the transverse beam profile with an overall space charge compensation of ~ 80% in the LEBT.

 

In this way, the MYRRHA LEBT will enable to study the physics of low energy hadron beams. It is crucial point to optimise the beam transmission and behaviour in the following parts of the accelerator. These studies would also be useful for all the actual high power hadrons accelerator projects (ESS, SPIRAL2, IFMIF-EVEDA, etc).