This project is funded by the NSF through grant PHY , and the Universities of JINA. The Joint Institute for Nuclear Astrophysics Henderson DUSEL Capstone Workshop A Recoil Separator for ALNA-Phase2 Manoël Couder University of Notre Dame Joint Institute for Nuclear Astrophysics

This project is funded by the NSF through grant PHY , and the Universities of JINA. The Joint Institute for Nuclear Astrophysics Henderson DUSEL Capstone Workshop Charged particles cross section measurements at low energy Effort to extract the signal at low energy are needed because cross section drops exponentially  Increase the number of interactions Beam intensity increased Gas target are more and more elaborated  Improved detection techniques Gamma detector: 4  segmented Active shielding

Tracking Arrays based on Position Sensitive Ge Detectors Large Gamma Arrays based on Compton Suppressed Spectrometers   40 — 20 % ( M  =1 — M  =30)   10 — 5 % ( M  =1 — M  =30) GAMMASPHEREEUROBALLGRETAAGATA Slide from: J. Simpson, “The AGATA project”, NPDC19, 2005

This project is funded by the NSF through grant PHY , and the Universities of JINA. The Joint Institute for Nuclear Astrophysics Henderson DUSEL Capstone Workshop Charge particles Cross section measurements at low energy – Status Effort to extract the signal at low energy (fight against background) are needed because cross section drops exponentially:  Increase the number of interactions Beam intensity increased Gas target are more and more elaborated  Try to extract more by improving detection techniques Gamma detector: 4  segmented Active shielding  Underground laboratory

This project is funded by the NSF through grant PHY , and the Universities of JINA. The Joint Institute for Nuclear Astrophysics Henderson DUSEL Capstone Workshop p, 4 He beam Target  rays Direct kinematics: Light ion beam on heavy target Find additional tags to improve detection for (p,) and (,) No additional tag possible only fight to increase signal to noise ratio.  rays p, 4 He target Inverse kinematics: “Heavy ion” beam on light target HI beam Reaction products 10  A for 1 recoil/10 min Require rejection of the beam-> RMS Existing device: Triumf Bochum …

This project is funded by the NSF through grant PHY , and the Universities of JINA. The Joint Institute for Nuclear Astrophysics Henderson DUSEL Capstone Workshop Triumf DRAGON ISAC Radioactive beam induce reaction -> Inverse kinematics is the only solution. Example with stable beam induce reaction 21 Ne(p,g) 22 Na Spectrum and picture from S. Engels Thesis, Recoil energy spectra in singles and coincidence mode for 21 Ne(p,  ) 22 Na at Ecm = keV Gamma energy spectrum in singles and coincidence mode Residual beam

This project is funded by the NSF through grant PHY , and the Universities of JINA. The Joint Institute for Nuclear Astrophysics Henderson DUSEL Capstone Workshop 12 C(,) 16 ERNA - Ecm = 3.2 MeV D. Schürmann, Santa Tecla 2005 Spectrum from D. Schürmann, Santa Tecla 2005 BaF 2  detector Signal Cosmic and room background Beam induced background F. Strieder, Tuckson 2003 Spectrum from F. Strieder, Tuckson 2003

This project is funded by the NSF through grant PHY , and the Universities of JINA. The Joint Institute for Nuclear Astrophysics Henderson DUSEL Capstone Workshop Why a RMS underground ?  The dramatic cosmic background reduction leaves the environmental and beam induce background.  The number of bad  – HI coincidence decrease !! The Notre Dame Recoil Mass separator  Design of a RMS for ( ,  ) reaction studies at low energy for beam with 16<A<40. Large acceptance  <40 mrad  E/E<7.4%  Required for reaction of interest: 22 Ne( ,  ) 26 Mg, 18 O( ,  ) 22 Ne  Mass separation achieved with a Wien filter  New design of the electrodes  First beam expected late 2007  Good prototype for underground laboratory  High intensity AC accelerator is required for beam up to A=40  Source and accelerator LBNL

This project is funded by the NSF through grant PHY , and the Universities of JINA. The Joint Institute for Nuclear Astrophysics Henderson DUSEL Capstone Workshop The Notre Dame RMS Charge selection Jet gas target + post-stripper  detectors Wien Filter – Mass separation Detection system 8cm Recoil Beam Recoil+Beam q selected Beam q+2 q+1

This project is funded by the NSF through grant PHY , and the Universities of JINA. The Joint Institute for Nuclear Astrophysics Henderson DUSEL Capstone Workshop G.P.A. Berg 1, M. Couder 1, J. Görres 1, J. Hinnefeld 2, L.O. Lamm 1, P.J. Leblanc 1, E. Stech 1, M. Wiescher 1 1 University of Notre Dame. 2 Indiana University, South Bend. Summary:  RMS must accept ALL the recoils  Large angular and energy acceptance  Low event rate ~1/few hours  Rejection important >10 20 beam ions  Low energy  No ID of the heavy ion, no additional discrimination   ray – HI coincidence is crucial to make a TRUE EVENT ID