200 likes | 304 Views
A University-based cyclotron laboratory for nuclear science. Maxime Brodeur. Importance of low-E NP research . Goal : understand the atomic nucleus. Three main topics of studies in the low-energy domain:. Fundamental symmetries Nuclear astrophysics Nuclear structure.
E N D
A University-based cyclotron laboratory for nuclear science Maxime Brodeur
Importance of low-E NP research Goal: understand the atomic nucleus Three main topics of studies in the low-energy domain: • Fundamental symmetries • Nuclear astrophysics • Nuclear structure By providing stable ion beams and some RIBs, ARUNA currently contributes in all subfields. These beams are however of limited reach ARUNA workshop – June 13, 2014
The problem Main options to perform experiments with exotic beams in the USA: • CARIBU/ATLAS at ANL • NSCL Highly competitive large user facilities Proposed Accepted Beam request largely exceed available time ARUNA workshop – June 13, 2014
Side-effects • Experiments requiring time cannot be performed • Few measurements can be done yearly The 2013 low-energy community meeting statement: “The community is concerned about the lack of beam time at existing facility and its impact on the workforce development” Propose to locally produce RIBs to address this need Result: reduced experimental time ARUNA workshop – June 13, 2014
Local RIB production TR24 from ACSI 1.1 barn at 24 MeV p-induced fission p from 24 MeV commercial cyclotron Ip~ 500mA H- machine; 2 simultaneous beams ARUNA workshop – June 13, 2014
Partnership Isotope production Notre Dame Cyclotron • The cyclotron and building will be financed by Notre Dame and the medical isotope company. • Operation of the cyclotron and operational costs (e.g. utilities) provided by the company Shared use of cyclotron with private partner Production of medical radioisotopes (99mTc, …) ARUNA workshop – June 13, 2014
Partnership Isotope production Notre Dame Cyclotron • Place where long-term and more challenging measurements can be done… • … while measurements on exceptionally exotic nuclei would be done at FRIB Day-time use for research (simultaneous also possible) Lots of beam availability for nuclear experiments ARUNA workshop – June 13, 2014
Long-term, challenging measurements Produced at low yield (<1 ion/h), requires long time (weeks) to perform the measurement • abn of mirror transition to test the electroweak interaction Challenging measurement requiring large statistics of long half-lived nuclei (t1/2 reaching 20 min.) m and Pnof exotic, relevant r-process nuclei ARUNA workshop – June 13, 2014
RIB production method Can change targets for optimal production • Fission (n-rich, r-process) • Fusion-evaporation (p-rich, mirror transitions) IG-ISOL method Universal Well-established Versatile ARUNA workshop – June 13, 2014
Calculated deliverable yields 238U(p,f) Ep = 30 MeV Ip = 10 mA • Comparable to CARIBU with 1 Ci252Cf source • Different yield distribution (complementary) Figure from J. Aysto ARUNA workshop – June 13, 2014
RIB separation 24 MeV p from cyclotron Fission product 24 MeV p from cyclotron • Non-isobaric contamination removed by dipole magnet ARUNA workshop – June 13, 2014
Isobaric purification 24 MeV p from cyclotron • Isobaric contamination removed by a multi-reflection time-of-flight separator • Can also be used for mass measurements RFQ cooler and buncher MR-TOF mass separator or spectrometer Pure bunches to Paul trap Bunches from RFQ Recall Yuan Mei’s talk ARUNA workshop – June 13, 2014
Experimental possibilities 24 MeV p from cyclotron Ion trap measurements: RFQ cooler and buncher Could also measure t1/2, … open to suggestions MR-TOF mass separator or spectrometer Or experiments with the protons themselves; e.g. STAR Paul trap for Pn measurements b-delayed n-emission BR abnof mirror transitions ARUNA workshop – June 13, 2014 Co
Which Pn can be done? Total of 160 Pn 70 Pnthat CARIBU cannot produce ARUNA workshop – June 13, 2014
Applied physics research opportunities • Some measurements also have applied physics interests e.g. Pn values are important for: • The design of next generation nuclear reactors • Stockpile stewardship ARUNA workshop – June 13, 2014
Applied physics research opportunities e.g. Alternate means to produce 99mTc • Used in 80% of nucl. med. procedures • Generated from 99Mo decay, which is produced by fission in reactors • In 2016: 2 reactors responsible to 2/3 world supply set to close • Alternative: 100Mo(p,2n) reaction using cyclotrons • Issue: purity of 99mTc produced • Contamination production s calculation done at UND (Couder) • smeasurements are underway (Couder) Medical radioisotopes research ARUNA workshop – June 13, 2014
Conclusion • The cyclotron facility will allow various funding opportunities • Like other ARUNA facilities, the unfair advantage of this facility over large user facilities is time. • Allows to make long-term measurements that cannot be done at large facilities The new RIB facility will help the nuclear physics community with beam time shortage. This unique American IG-ISOL facility would provide a training opportunity in tomorrow’s scientific workforce ARUNA workshop – June 13, 2014
Backup slides ARUNA workshop – June 13, 2014
RIB cooling and bunching 24 MeV p from cyclotron RFQ cooler and buncher Cooled bunches Continuous beam ARUNA workshop – June 13, 2014
Pn measurements 24 MeV p from cyclotron RFQ cooler and buncher MR-TOF mass separator or spectrometer Paul trap for Pn measurements ARUNA workshop – June 13, 2014