• B.M. Hegelich
  LMU, München

Par­ti­cle ac­cel­er­a­tion with high power lasers has been demon­strat­ed by var­i­ous mech­a­nisms, ac­cel­er­at­ing elec­trons to GeV en­er­gies. So far, ion en­er­gies were stuck in the MeV range un­less one could reach in­ten­si­ties ≥ 10²⁴ W/cm². These pa­ram­e­ters are dis­cour­ag­ing for ad­vanced ac­cel­er­a­tor con­cepts and un­ac­cept­able for ap­pli­ca­tions like Ion-driv­en Fast Ig­ni­tion (IFI) or hadron ther­a­py. The re­al­iza­tion of ul­tra­high con­trast lasers and free stand­ing nm-thin laser tar­gets how­ev­er marks a paradigm shift. The com­bi­na­tion of these two tech­niques en­ables a num­ber of new ion ac­cel­er­a­tion mech­a­nisms that have been ob­served in sim­u­la­tions and promise GeV ion en­er­gies. Ex­am­ples are the Break-Out Af­ter­burn­er (BOA) ac­cel­er­a­tion and the Phase-Sta­ble Ac­cel­er­a­tion (PSA) regime, also re­port­ed as Ra­di­a­tion Pres­sure Ac­cel­er­a­tion (RPA). Here we pre­sent the first ex­per­i­men­tal re­al­iza­tion of the BOA ac­cel­er­a­tion mech­a­nism, achiev­ing 0.5 GeV car­bon ions out of a sin­gle laser ac­cel­er­a­tion stage at the Los Alam­os Tri­dent laser. Full 3D-PIC sim­u­la­tions at full solid den­si­ty con­firm ear­li­er 1- and 2D re­sults, and are in good agree­ment with the ex­per­i­men­tal data. More­over, hav­ing been per­formed be­fore the ex­per­i­ment, they ex­hib­it ex­traor­di­nary pre­dic­tive power. We will dis­cuss the re­quire­ments this poses on the drive lasers es­pe­cial­ly con­cern­ing the pulse con­trast and re­port first ex­per­i­men­tal re­sults in re­al­iz­ing those con­di­tions and how to scale to fu­ture lasers.

Slides

• I. Hofmann, A. Orzhekhovskaya, S. Yaramyshev
  GSI, Darmstadt
• I. Alber, K. Harres, M. Roth
  TU Darmstadt, Darmstadt

Funding: Work supported by EURATOM (IFE KiT Program).

The re­cent de­vel­op­ment in laser ac­cel­er­a­tion of pro­tons and ions has stim­u­lat­ed ideas for using this con­cept as in­no­va­tive and com­pact ther­a­py ac­cel­er­a­tor. While cur­rent­ly achieved pa­ram­e­ters do not allow a re­al­is­tic con­cep­tu­al study yet we find that our sim­u­la­tion stud­ies on ion col­li­ma­tion and trans­port, based on out­put data from the PHE­LIX ex­per­i­ment, al­ready give a use­ful guid­ance. Of par­tic­u­lar im­por­tance are the chro­mat­ic and ge­o­met­ric aber­ra­tions of the first col­li­ma­tor as in­ter­face be­tween the pro­duc­tion tar­get and a con­ven­tion­al ac­cel­er­a­tor struc­ture. We show that the re­sult­ing 6D phase space match­es well with the re­quire­ments for syn­chrotron in­jec­tion.

Slides

• H. Palancher
  CEA-IRFU, Gif-sur-Yvette

Funding: This work has been performed in collaboration with FRMII (Munich, Germany) at the MLL tandem accelerator.

For de­vel­op­ing new gen­er­a­tions of nu­cle­ar fuels, in-pile ex­per­i­ments are re­quired. How­ev­er con­sid­er­ing their price and the delay (a few years) be­tween their de­sign and their anal­y­sis, each tech­no­log­i­cal so­lu­tion can not be test­ed in nu­cle­ar fuel re­ac­tors. For that pur­pose, al­ter­na­tive strate­gies have to be de­fined, with the view to iden­ti­fy the best can­di­date to test in-pile. This talk will be fo­cused on the in­ter­est of heavy ion ir­ra­di­a­tion for the se­lec­tion of low en­riched ²³⁵U nu­cle­ar fuels. To ful­fill the re­quire­ments of in­ter­na­tion­al non-pro­lif­er­a­tion treaty, high den­si­ty UMo al­loys ap­pear as the only ap­pro­pri­at­ed fuel ma­te­ri­al es­pe­cial­ly for the most pow­er­ful re­search re­ac­tors cores (ma­te­ri­al test­ing re­ac­tors, neu­tron sources). UMo fuel el­e­ments usu­al­ly con­sist of fis­sile par­ti­cles dis­persed in an Al ma­trix. How­ev­er their in-pile be­hav­ior is cur­rent­ly not sat­is­fac­to­ry be­cause of the growth of a large in­ter­ac­tion layer at UMo/Al in­ter­faces under ir­ra­di­a­tion. Heavy ion ir­ra­di­a­tions with 80 MeV ¹²⁷I ions have been suc­cess­ful­ly used to sim­u­late the dam­ages caused by the fis­sion prod­ucts at the UMo/Al in­ter­face. The growth of an in­ter­ac­tion layer has been re­pro­duced thanks to this out-of-pile method­ol­o­gy. This al­lows to se­lect reme­dies (sil­i­con ad­di­tion to the alu­minum ma­trix, UMo par­ti­cle coat­ing,…) for the growth of this in­ter­ac­tion layer.

Slides

• A. Roy
  IUAC, New Delhi

Con­fer­ence Clos­ing Re­marks.

Slides