TRIUMF — RESEARCH PROPOSAL 927 Sheet 1 of 20

TRIUMF — RESEARCH PROPOSAL �Experiment no.

927Sheet 1 of 20

Title of proposed experiment:

Using (3He,p): Spectroscopy of proton unbound 19Na

Name of group: TUDA

Spokesperson for group: F. Sarazin / L. Buchmann

E-Mail address: [email protected], [email protected] Fax number: 222-1074

Members of the group (name, institution, status, per cent of time devoted to experiment)

F. Sarazin TRIUMF Research Fellow 30%L. Buchmann TRIUMF Senior Research Scientist 30%G. Ball TRIUMF Senior Research Scientist 20%G. Hackman TRIUMF Research Scientist 20%A. Laird TRIUMF Research Associate 30%A. Shotter TRIUMF Director/Full Professor 10%P. Walden TRIUMF Senior Research Scientist 20%A. Chen SFU Research Fellow 20%T. Davinson Univ. Edinburgh Research Scientist 30%C. Ruiz Univ. Edinburgh Graduate Student 30%I. Roberts Univ. Edinburgh Graduate Student 30%A. Robinson Univ. Edinburgh Graduate Student 30%P. Woods Univ. Edinburgh Full Professor 20%B. Fulton Univ. York Full Professor 20%D. Groombridge Univ. York Research Fellow 20%J. Pearson Univ. York Graduate Student 20%C. Svensson Univ. Guelph Research Scientist 10%J. Waddington Univ. McMaster Professor 10%

Start of preparations: February 2002

Date ready: Fall 2002

Completion date: 2005

Beam time requested:

12-hr shifts Beam line/channel Polarized primary beam?

34 TUDA @ ISACI/II No

SUMMARY Expt # 927 Sheet 2 of 20

We propose to determine if the structure of proton unbound 19Na allows the considera-tion of the two-proton capture reaction 18Ne(2p,γ)20Mg as a viable alternative for bridgingthe waiting point 18Ne at high temperature and density conditions. In order to obtainthe level structure of the proton unbound 19Na, we propose to use the transfer reaction17Ne(3He,p)19Na in inverse kinematics at the TUDA scattering facility employing a 3Hegas cell and a 17Ne radioactive beam. The high Q-value of this reaction (Q=11.199MeV)should allow us to measure a wide range of new proton unbound states in 19Na, includingthe low energy ones which are of astrophysical interest. The calibration of the proton de-tectors will be obtained by the identification of the known proton unbound states in 20Nausing the 18Ne(3He,p)20Na reaction, which would demonstrate a new method to measurethe states above the proton threshold in 20Na, another key nucleus in the description of thebreak-out reaction of the hot CNO cycles via 19Ne(p,γ)20Na. Further uses of the (3He,p)reaction are 24Al(3He,p)26Si as discussed in the proposal of A. Chen and 29P(3He,p)31Sin the context of the 30P(p,γ)31S reaction. In a first phase tests with stable beams arerequested.

BEAM REQUIREMENTS Expt # 927 Sheet 3 of 20

Experimental area

ISAC-HE, TUDA, eventually ISAC II

Primary beam and target (energy, energy spread, intensity, pulse characteristics, emittance)

Secondary channel ISAC-HE

Secondary beam (particle type, momentum range, momentum bite, solid angle, spot size, emmittance, intensity,beam purity, target, special characteristics)

p-MgO or SiC, 500 MeV, cwECR Source

17Ne (unstable) up to 106 pps, 1.6 MeV/u, 5 MeV/u18Ne (unstable) up to 108 pps, 1.6 MeV/u, 5 MeV/u

SUPPORT REQUIREMENTS Expt # 927 Sheet 4 of 20

TRIUMF SUPPORT:

NON-TRIUMF SUPPORT

TUDA like facility (TUDAII) at ISACII.

The TUDA facility, including considerable manpower for setup and operation, has beenprovided by U. of Edinburgh and U. of York. This support will continue. The TUDAcollaboration is supported both by an EPSRC (UK) and by a NSERC grant (Canada) formanpower, replacement parts and computing support. The He gas cell is currently underdevelopment at the U. of York. The E detection system has to be developed using bothscintillators and silicon arrays. The later needs additional NSERC support to be appliedfor.

SAFETY Expt # 927 Sheet 5 of 20

Standard TUDA operation with short lived radioactive isotopes, (18Ne, T1/2=1.67s,17Ne, T1/2=109.2ms). Low voltage detectors and electronics. Gas cell target.

DETAILED STATEMENT OF PROPOSED RESEARCH Expt # 927 Sheet 6 of 20

1 Scientific Justification

Explosive hydrogen burning is thought to be the main source of energy generation innovae and X-ray bursters, and also provides an important route for nucleosynthesis via therp process [1]. The leak rate of material between the CNO cycles and the rp-process (Z≥10)is mainly limited by the waiting point nuclei 15O (T1/2=122s) and 18Ne (T1/2=1.67s), sincea new proton capture leads to proton unstable 16F and 19Na, respectively. It is believedthat these two waiting points are bridged at higher temperature and density conditionsby the capture reaction sequences 15O(α,γ)19Ne(p,γ)20Na and 18Ne(α,p)21Na(p,γ)22Mg,both involving an α capture.

However, similarly to the triple-alpha reaction, where unbound 8Be is created as anintermediate state toward the creation of 12C, it is possible to consider a 2-proton captureprocess, which would connect 15O with 17Ne and 18Ne with 20Mg via respectively theunbound 16F and 19Na nuclei as intermediate states. To address this question, a preciseknowledge of the structure of a few states in these unbound nuclei is required. J. Gorreset al. estimate that the reaction rates deduced for this process cannot compete realisti-cally with the reaction rate of their respective alpha-induced reaction for typical stellarconditions [2] (X-ray burst). However, in the case of 19Na, only the ground state and firstexcited state have been observed once with a quoted precision in energy of about 10 keV[3]. The other parameters in the calculation [2] were based on theoretical considerations.An accurate determination of the energy and width of the ground state and the first ex-cited states of 19Na as well as an experimental spin assignment of these states are neededto fully calculate the reaction rate of the 2-step reaction 18Ne(2p,γ)20Mg.

It is also worth noting that, since 19Na is unbound by only 320keV, an almost uniquecase among the light nuclei, it may be an excellent candidate to study the Thomas-Ehrmann effect beyond the proton drip-line [4,5]. Interestingly, while the other protonunbound nuclei display a Thomas-Ehrmann shift tending to lower the unbound statescompared to their bound mirror states, 19Na shows an inverse effect for the only knownexcited state [6]. In addition, 19Na has a closed N=8 neutron shell and its states can bemade subject to thorough shell or other model calculations.

For calibration purposes, proton unbound states in 20Na can also be investigated ina new way. It is believed that most of the low lying states above the proton thresholdin 20Na, expected to participate to the important astrophysical step 19Ne(p,γ)20Na, havebeen already identified [7]. There are, however, still ongoing discussions concerning thespin of some of these states, in particular for the important state at 2643-keV which is thestate thought to dominate the reaction rate for novae since it lies only 448keV above the19Ne+p threshold [8]. In this context, angular distributions obtained by transfer reactionmay give some new insights for spin assignment.

2 Description of the Experiment

We propose to use the transfer reaction 17Ne(3He,p)19Na in inverse kinematics at theTUDA general scattering facility [9] employing a 3He gas cell. The high Q-value of thisreaction (Q=11.199MeV) allows us to populate a wide range of states including the ground


state in 19Na. More generally, (3He,p) reactions have been used extensively in the past asa viable alternative to elastic scattering measurement to survey a wide range of excitationenergies (See for example Ref. [10]). The He gas cell is currently under development atthe University of York and its design has already been discussed in a previous acceptedproposal [11] for the 18Ne(α,p) reaction, which would involve measuring much smallercross section. Its design was driven by the necessity to reduce the proton background inthe detectors to the minimum. The design of this cell remains however fairly flexible anda consensus should be easy to reach.

The energy of the beam will be at maximum for ISAC I, i.e. 1.64 MeV/u. Thiscorresponds to a cm energy of 4.1 MeV for the 3He+17Ne system. For this energy the18Ne(α,p)21Na reaction with a nearly identical Coulombbarrier has been observed. If crosssections at these energies for the available radioactive beam/cross section combinationsprove too small or beamschedules delay things, the experiment will be continued at ISACII at 5 MeV/u.

The proposed reactions imply the detection in coincidence of the proton issued fromthe transfer reaction and the proton subsequently emitted by the decaying compoundnuclei. These two protons can be well identified in LEDA-type silicon arrays [12] or othersilicon strip detectors such as a CD-type array (see fig 1). We plan to use two LEDA andone CD arrays in order to cover a large solid angle, two detector being used to cover theforward angle, the third one to cover the backward angle in the laboratory frame (Seefig.2). The CD detector covering the most forward angles (<20 degrees) would mainly beused to detect the proton from the transfer reaction emitted when the recoil is emittedin the backward angle in the center of mass. Due to their high energy (up to 23 MeV),the identification will be provided by a ∆E-E system. A CD detector in front will providethe ∆E as well as the angle, while a thick single non-segmented silicon detector will stopthe protons and thus provide the E. Initially scintillators maybe used as E detectors. Thedevelopment of ∆E-E capabilities will be of great importance for transferring TUDA toISACII. A mylar foil will be used to protect the detector from the scattered beam andother heavy ions products. A first LEDA detector, possibly in its LAMP configuration[12], will be also placed downstream of the target in order to cover the large forward anglebeyond the maximum scattering angle of the beam. A thin mylar foil might howeverbe necessary to stop a small fraction of the beam which may be scattered on the exitfoil of the gas cell. This LEDA detector will cover the region where most of the protonoriginating from 19Na should be emitted (See fig.3). Finally, the second LEDA array willbe placed upstream of the target to provide a larger angular coverage for the detectionof the proton originating from the transfer reaction. The distances of the detectors withrespect to the target and the thicknesses of the foil will be optimized for each reactionstudied. The calibration of the proton detectors will be obtained by using the reaction18Ne(3He,p) which leads to 20Na and 20Ne(3He,p)22Na which stable reaction will be alsoused for setup purposes. In the stable beam runs, it will also be investigated, how a vertexreconstruction can be used to determine the lifetime of narrow states. By comparison ofpopulation of an excited state, the ratio of total and partial widths can be established,allowing in some cases for ωγ determinations. The addition of γ-detection capabilities atTUDA is under consideration.

One advantage of this method compared to the resonant elastic scattering, is that onlyone energy (at maximum) is needed to scan the excitation scheme of 19Na and 20Na.


If successful, it is proposed to use the method also in 24Al(3He,p)26Si as discussedin the proposal of A. Chen and 29P(3He,p)31S in the context of the 30P(p,γ)31S reactionimportant in Ne novae.

3 Experimental Equipment

Very recently, the TUDA general scattering facility has been proved successful inmeasuring resonances of astrophysical interest in 22Mg by resonant elastic scattering [13].In particular, the mylar foils in front of the detectors have been very efficient in reducingthe scattered beam while not affecting significantly the proton energy resolution.

The design of the gas target is still under discussion at the University of York andtherefore remains flexible. A few minor modifications would be planned if beamtime isgranted to this experiment, in particular concerning the entrance section of the targetwhich should allow the proton to be detected at the backward angles. The original ac-cepted experiment using the He cell is also planning to use a 18Ne beam. Therefore,it is expected to be ready for Spring-Summer 2002 date for which the radioactive Nebeam should be available for experiments. In this experiment, the beam would be passedthrough the cell and dumped outside the TUDA chamber.

Up to now, the TUDA facility has been running with two LEDA configuration down-stream to the target. An upgrade of the facility will consist in adding new feed-throughsat the back of the chamber to allow the chamber to support one or two LEDA configu-rations at the backward angle in the laboratory frame. A new LEDA system is alreadyavailable and is to be tested. The upgrade will be completed well before the expected datefor availability of the 17−18Ne beams.

Because proton energies are very high, the existing LEDA arrays will not fully stopthem. Therefore a full energy detection capacity has to be developed. This will allow forunique particle identification. Scintillators may serve as a first step, while later silicondetectors can provide additional angular information. Silicon detectors need additionalfunding not presently available.

4 Readiness

The TUDA chamber and infrastructure for data acquisition is available. This spring(2002) we plan for the installation of VME based spectroscopic ADCs permitting morechannels and higher data acquisition rates. Feedthroughs for the use of back-hemispheredetectors will also be installed. Some aspects of the experiment will be ready by May 1,2002, while runs with radioactive ions may realistically start end of 2002.

5 Beam Time required

While the yields for 17Ne have not yet been determined at ISAC, from TISOL expe-rience (max. yield 2×105 s−1 from a MgO target) it is expected that about 105 17Ne


can be delivered to the TUDA target. With a target of 1019 cm−2 thickness of 3He andcross sections of about 1 mb into a specific transition this results in (about 1/3 detec-tion efficiency) 1 event/hour/transition. With the usual inefficiencies in operation about100 events/transition are therefore expected in a two week period of running in which noenergy changes would be necessary.

We propose, however, that the experiment be thoroughly tested before proceeding to17Ne. Therefore we propose to start with stable beam 20Ne(3He,p)22Na reaction observingwell known resonances in 21Ne+p. From there we go to the use of a 18Ne beam for a fewdays. A 18Ne beam should have at least two orders of magnitude more intensity than17Ne. When 18Ne beams are available, the 17Ne yield at the TUDA target should be wellestablished. With the reaction rate for two similar (A,Z) nuclei known, we would returnto the EEC for seeking approval for the final runs.

6 Data Analysis

The principle of the experiment requires the detection in coincidence of 2 protons inthe charged particle detectors. This provides a natural clean trigger for the experiment.The acquisition is then expected to work at a low rate. Previous experiments at TUDAshowed that the acquisition system can support a 3kHz trigger with no more than 30%dead time. Events will be written both onto disk and tape (DLT). On-line data analysistools are installed on devoted computers based on Sun Solaris system. For off-line analysisseveral computing systems are available at TRIUMF.

On-line analysis will be done using the standard tools of analysis (PAW, Midas,...).A Monte Carlo simulation will be written to simulate the simultaneous emission of thetwo protons and to identify the proton originating from the very short lived compoundnucleus. Finally, DWBA calculations will be used to fit the proton angular distributionto assign the spin of the observed excited states.


References

1. A.E. Champagne and M. Wiescher, Ann. Rev. Nucl. Part. Sci 42 (1992) 39

2. J. Gorres, M. Wiescher and F-K. Thielemann, Phys. Rev. C51 (1995) 392

3. W. Benenson et al., Phys. Lett. B58 (1975) 46

4. R.G. Thomas, Phys. Rev. 80 (1950) 136 ; Phys. Rev. 88 (1952) 1109

5. J.B. Ehrmann, Phys. Rev. 81 (1951) 412

6. E. Comay, I. Kelson and A. Zidon, Phys. Lett. B210 (1988) 31

7. G. Vancraeynest et al., Phys. Rev. C57 (1998) 2711

8. H.T. Fortune et al., Phys. Rev. C61 (2000) 057303

9. A.C. Shotter, Letter of intent, TRIUMF (1998)

10. J.D. Garrett et al., Nucl. Phys. A164 (1971) 449

11. A.C. Shotter and L. Buchmann, ISAC proposal E870 (1999)

12. T. Davinson, NIM A454 (2000) 350

13. C. Ruiz, F. Sarazin, L. Buchmann et al., to be submitted


26 cm

Active silicon area

10 cm

��

��

��

��

��

��

��

2

42.5

85

15

Back Face

Pixel

Front Face3.5 o

20

310

120 70

The LEDA �top�� CD �middle� and SWAN �bottom� detector arrays�

Fig. 1 The LEDA (top) and CD (bottom) detector arrays


p1:

prot

on f

rom

tra

nsfe

r re

acti

onp2

: pr

oton

fro

m s

ubse

quen

t de

cay

of 1

9Na

p2p1L

ED

A2

GA

S C

EL

L

LE

DA

1 (L

AM

P)

CD

+ t

hick

Non

-Seg

. Si

Bea

m

Fig. 2 Schematic configuration of the experimental setup


6

8

10

12

14

16

18

20

22

24

0 20 40 60 80 100 120 140 160 180

Proton from (3He,p) tranfer

0

0.5

1

1.5

2

2.5

3

3.5

0 5 10 15 20 25 30 35 40 45 50

Proton from the decay of 19Na

Fig. 3 Top: kinematic of the proton emitted from the transfer reaction ; Bottom: kinematic of theproton emitted from decaying 19Na. (X-axis: laboratory angle (degrees); Y-axis: energy (MeV) )

PUBLICATION LIST OF SPOKESPERSON(S) Expt # 927 Sheet 14 of 20

Include publications in refereed journal over at least the previous 5 years.

1. C.Ruiz, F.Sarazin, L.Buchmann, T.Davinson, A.A.Chen, D.Groombridge, L.Ling,A.Murphy, J.Pearson, I.Roberts, A.Robinson, A.S.Shotter, P.Walden, P.J.Woods,

strong resonances in elastic scattering of radioactive 21Na on protons

To be submitted to Phys. Rev. C (2001).

2. F.M.Marques, M.Labiche, N.A.Orr, J.C.Angelique, L.Axelsson, B.Benoit, U.Bergmann,M.J.G.Borge, W.N.Catford, S.P.G.Chapell, N.M.Clarke, G.Costa, N.Curtis, A.DArrigo,F.de Oliveira, E.de Goes Brennand, O.Dorvaux, M.Freer, B.R.Fulton, G.Giardina,C.Gregori, S.Grevy, D.Guillemaud-Mueller, F.Hannappe, B.Heusch, B.Jonson, C.LeBrun, S.Leenhardt, M.Lewitowicz, M.J.Lopez, K.Markenroth, M.Motta, A.C.Mueller,T.Nilsson, A.Ninane, G.Nyman, I.Piqueras, K.Riisager, M.G.Saint-Laurent, F.Sarazin,S.M.Singer, O.Sorlin, L.Stuttge,

Three-body correlations in Borromean halo nuclei

Accepted by Phys. Rev. C (2001).

3. M.Labiche, N.A.Orr, F.M.Marques, J.C.Angelique, L.Axelsson, B.Benoit, U.Bergmann,M.J.G.Borge, W.N.Catford, S.P.G.Chapell, N.M.Clarke, G.Costa, N.Curtis, A.D’Arrigo,F.de Oliveira, E.de Goes Brennand, O.Dorvaux, G.Fazio, M.Freer, B.R.Fulton,G.Giardina, S.Grevy, D.Guillemaud-Mueller, F.Hannappe, B.Heusch, K.L.Jones,B.Jonson, C.Le Brun, S.Leenhardt, M.Lewitowicz, M.J.Lopez, K.Markenroth, A.Mueller,T.Nilsson, A.Ninane, G.Nyman, I.Piqueras, K.Riisager, M.G.Saint-Laurent, F.Sarazin,S.M.Singer, O.Sorlin, L.Stuttge,

The halo structure of 14Be

Phys. Rev. Lett. 86 (2001) 600.

4. F.Sarazin, H.Savajols, W.Mittig, F.Nowacki, N.A.Orr, Z.Ren, P.Roussel-Chomaz,G.Auger, D.Baiborodin, A.V.Belozyorov, C.Borcea, E.Caurier, Z.Dlouhy, A.Gillibert,A.S.Lalleman, M.Lewitowicz, S.M.Lukyanov, F.de Oliveira, Y.E.Penionzhkevich,D.Ridikas, H.Sakurai, O.Tarasov, A.de Vismes,

Shape coexistence and the N=28 shell closure far from stability

Phys. Rev. Lett. 84 (2000) 5062.

5. A.de Vismes, P.Roussel-Chomaz, W.Mittig, A.Pakou, N.Alamanos, F.Auger, J.Barrette,A.V.Belozyorov, W.N.Catford, Z.Dlouhy, A.Gillibert, V.Lapoux, A.Lepine-Szily,S.M.Lukyanov, F.Marie, A.Musumarra, F.de Oliveira, N.A.Orr, S.Ottini-Hustache,Y.E.Penionzhkevich, F.Sarazin, H.Savajols,

A determination of the 6He+p interaction potential

Phys. Lett. B476 (2000) 219


6. F.M.Marques, M.Labiche, N.A.Orr, J.C.Angelique, L.Axelsson, B.Benoit, U.Bergmann,M.J.G.Borge, W.N.Catford, S.P.G.Chapell, N.M.Clarke, G.Costa, N.Curtis, A.DArrigo,F.de Oliveira, E.de Goes Brennand, O.Dorvaux, M.Freer, B.R.Fulton, G.Giardina,C.Gregori, S.Grevy, D.Guillemaud-Mueller, F.Hannappe, B.Heusch, B.Jonson, C.LeBrun, S.Leenhardt, M.Lewitowicz, M.J.Lopez, K.Markenroth, M.Motta, A.C.Mueller,T.Nilsson, A.Ninane, G.Nyman, I.Piqueras, K.Riisager, M.G.Saint-Laurent, F.Sarazin,S.M.Singer, O.Sorlin, L.Stuttge,

Two-Neutron Interferometry as a probe of the Nuclear Halo

Phys. Lett. B476 (2000) 219

7. F.M.Marques, M.Labiche, N.A.Orr, F.Sarazin and J.C.Angelique,

Neutron cross-talk rejection in a modular array and the detection of neutron haloes

NIM A450 (2000) 109.

8. Z.Ren, W.Mittig and F.Sarazin,

Relativistic mean-field study on proton skins and proton halos in exotic nuclei

Nucl. Phys. A652 (1999) 250-270

Publications LB:

7 Refereed Journals

1. L. Buchmann, “Radiative cascade transitions and the 12C(α,γ)16O E2 cross sectionto the ground state of 16O”, Phys. Rev. C., 64 022801(R) (2001)

2. N. Bateman, K. Abe, G. Ball, L. Buchmann, J. Chow, J.M.D’Auria, Y. Fuchi, C. Il-iadis, H. Ishiyama, K.P. Jackson, S. Karataglidis, S. Kato, S. Kubono, K. Kumagai,M. Kurokawa, X. Liu, S. Michimasa, P. Strasser, and M.H. Tanaka, “ Measure-ment of the 24Mg(p,t)22Mg reaction and implications for the 21Na(p,γ)22Mg stellarreaction rate”, Phys. Rev. C, 63 (2001) 035803

3. L.Buchmann, E.Gete, J.C.Chow, J.D.King, and D.F. Measday, “The β-delayed par-ticle decay of 9C and the A-9, T=1/2 nuclear system; R-matrix fits, the A=9 nuclearsystem, and the stellar reaction rate of 4He(αn,γ)9Be”, Phys. Rev. C., 63 (2001)034303

4. E.Gete, L.Buchmann, R.E.Azuma, D.Anthony, N.Bateman, J.C.Chow, J.M.D’Auria,M.Dombsky, U.Giesen, C.Illiadis, K.P.Jackson, J.D.King, D.F. Measday, and A.C.Morton,“The β-delayed particle decay of 9C and the A-9, T=1/2 nuclear system; Experi-ment, data and phenomenological analysis”, Phys. Rev. C., 61 (2000) 064310

5. A.Y.Zyuzin, L.R.Buchmann, J.S.Vincent, K.R.Buckley, N.O.Bateman,K.A.Snover, J.M.Csandjan, T.D.Steiger, E.G.Adelberger, and H.E.Swanson, “Metal-lic beryllium-7 target of small diameter”, Nucl. Inst. Meth., A438 (1999) 109


6. E.G.Adelberger, S.A.Austin, J.N.Bahcall, A.B.Balantkin, G.Bertsch, G.Bognert,L.S.Brown, L.Buchmann, F.E.Cecil, A.E.Champagne, L. de Braeckeleer, C.A.Duba,S.E.Elliott, S.J. Freedman, M.Gai, C.Goldring, C.R.Gould, A.Cruzinov, W.C.Haxton,K.M. Hoeger, E.Henley, C.W.Johnson, M. Kamionskowski, R.W. Kavanaugh, S.E.Koonin,K.Kubodera, K.Langanke, T. Motobayashi, V, Pandharipande, P.Parker, R.G.H.Robertson, C.Rolfs, R.F. Sawyer, N.Shaviv, T.D.Shoppa, K.Snover, E.Swanson,R.E.Tribble, S. Turck-Chiene, and J.F. Wikerson, “Solar Fusion Rates”, Rev. Mod.Phys., 70 (1998) 1265

7. J.Gorres, J. Meißner, H.Schatz, E.Stech, P.Tischhauser, M.Wiescher, R.Harkewics,B.Sherrill, M.Steiner, D. Bazin, M.Hellstrom, D.J.Morrissey, R.N.Boys, L.Buchmann,D.H.Hartmann, J.D.Hinnefeld,“Lifetime of 44Ti as probe of supernova models”,Phys. Rev Lett. 80 (1998) 2554

8. J.C.Chow, A.C.Morton, R.E.Azuma, N.Bateman, R.N.Boyd, L.Buchmann, J.M.D’Auria,T.Davinson, M.Dombsky, W.Galster, E.Gete, U.Giesen, C.Iliadis, K.P.Jackson, J.D.King,G.Roy, T.Shoppa, and A.Shotter, “Three-particle break-up of the isobaric analoguestate in 17F”, Phys. Rev. C 57, (1998) R475

9. J.A.Behr, A.Gorelov, T.Swanson, O.Hausser, K.P.Jackson, M.Trinczek, U.Giesen.J.M.D’Auria, R.Hardy, T.Wilson, P.Choboter, F.Leblond,L.Buchmann, M.Dombsky, C.D.P. Levy, G.Roy, B.A.Brown, and J.Dilling, “Magneto-optic trapping of β-decaying 38mK, 37K from an on-line isotope separator”, Phys.Rev. Lett. 79, (1997) 375

10. J.D’Auria, L.Buchmann, D.Hutcheon, P.Lipnik, D.Hunter, J.Rogers, R.Helmer, U.Giesen,A.Olin, P.Bricault, N.Bateman, “A facility for studying radiative capture reactionsinduced with radioactive beams at ISAC”, Nucl. Inst. Meth. B, 126 (1997) 262

11. L.Buchmann, “New stellar reaction rate for 12C(α,γ)16O”, Ap.J., 468 (1996) L127,Erratum: Ap.J., 479 (1997) L153

12. C.Iliadis, R.E.Azuma, L.Buchmann, J.Chow, J.M.D’Auria, M.Dombsky, U.Giesen,J.D.King, and A.C. Morton, “Beta-delayed particle decay of 36K”, Nucl. Phys. A609 (1996) 237

13. L.Buchmann, R.E.Azuma, C.A.Barnes, K,Langanke, and J.Humblet, “An analysisof the total 12C(α,γ)16O cross section based on available angular distributions andother primary data”, Phys. Rev. C, 54, (1996) 393

14. C.Iliadis, L.Buchmann, P.M.Endt, H.Herndl, and M.Wiescher, ”New stellar reactionrates for 25Mg(p,γ)26Al and 25Al(p,γ)26Si”, Phys.Rev. C, 53 (1996) 475

15. R.E.Azuma, L.Buchmann, F.C.Barker, C.A.Barnes, J.D’Auria, M.Dombsky, U.Giesen,K.P. Jackson, J.D.King, R.Korteling, P.McNeely, J.Powell, G.Roy, J.Vincent, T.R.Wang,S.S.M.Wong, and P.W.Wrean, ”Constraints on the low-energy E1 cross section of12C(α,γ)16O from the β-delayed α-spectrum of 16N”, Phys. Rev. C., 50 (1994) 1194Erratum Phys. Rev. C., 56 (1997) 1655

16. M.Dombsky, L.Buchmann, J.M.D’Auria, U.Giesen, K.P.Jackson, J.D.King, E.Korkmaz,R.Korteling, P.McNeely, J.Powell, G.Roy, M.Trinczek, and J.Vincent, ”β-delayed α-Decay of 17N”, Phys. Rev. C, 49 (1994) 1867


17. S.Kubono, C.C.Yun, R.N.Boyd, L.R.Buchmann, Y.Fuchi, M.Hosaka, N.Ikeda, C.L.Jiang,I.Katayama, H.Kawashima, H. Miyatake, T.Niizeki, T.Nomura, A.Odawara, M.Ohura,H.Ohnuma, H.Orihara, C.Rolfs, T. Shimoda, Y. Tajima, M.H.Tanaka, and H.Toyokawa,“High resolution study of 24Mg(d,p)23Mg for the Ne-E problem”, Z.Phys. A 348(1994) 59

18. L.Buchmann, R.E.Azuma, C.A.Barnes, J.D’Auria, M.Dombsky, U.Giesen, K.P. Jack-son, J.D.King, R.Korteling, P.McNeely, J.Powell, G.Roy, M.Trinzcek, J.Vincent,S.S.M.Wong, and P.W.Wrean “A study of beta delayed alpha emission from 16N”Nucl. Inst. Meth., B79 (1993) 330

19. L.Buchmann, R.E.Azuma, C.A.Barnes, A.Chen, J.Chen, J.D’Auria, M.Dombsky,U.Giesen, K.P. Jackson, J.D.King, R.Korteling, P.McNeely, J.Powell, G.Roy, M.Trinzcek,J.Vincent, S.S.M.Wong, and P.W.Wrean “The β-delayed α-spectrum of 16N and thelow-energy extrapolation of the 12C(α,γ)16O cross section”, J. Phys. G Nucl. Part.Phys. 19 (1993) S115

20. L.Buchmann, R.E.Azuma, C.A.Barnes, J.D’Auria, M.Dombsky, U.Giesen, K.P. Jack-son, J.D.King, R.Korteling, P.McNeely, J.Powell, G.Roy, J.Vincent, T.R.Wang,S.S.M.Wong, and P.W.Wrean, “β-delayed α-spectrum of 16N and the 12C(α,γ)16Ocross section at low energies”, Phys. Rev. Let. 70,6 (1993) 726

21. J.M.D’Auria, L.Buchmann, M.Dombsky, P.McNeely, G.Roy, H.Sprenger, and J.Vincent,“Upgrade of the TRIUMF on-line separator, TISOL”, Nucl. Inst. Meth., B70 (1992)75

22. M.Dombsky, L.Buchmann, J.M.D’Auria, P.McNeely, G.Roy, H.Sprenger, and J.Vincent,“Targets and ion sources at the TISOL facility”, Nucl. Inst. Meth., B70 (1992) 125

23. L.Buchmann, J.Vincent, H.Sprenger, J.D’Auria, M.Dombsky, P.McNeely, and G.Roy,“The ECR ion source at the TRIUMF isotope separator TISOL”, Rev.Sci.Instrum.,63,4 (1992) 2387

24. C.D.P.Levy, L.Buchmann, K.Jayamanna, M.McDonald, R.Ruegg, P.W.Schmor andA.N.Zelenski, “A d.c. polarized H− ion source based on optically pumped rubidium”,Rev.Sci.Instrum., 63,4 (1992) 2625

25. L.Buchmann, J.Vincent, H.Sprenger, M.Dombsky, J.M.D’Auria, P.McNeely, andG.Roy, ”The ECR ion source at the TRIUMF isotope separator, TISOL”, Nucl.Inst. Meth. B62 (1992) 521

26. J.D.King, D.Frekers, R.Abegg, R.E.Azuma, L.Buchmann, C.Chan, T.E.Drake, R.Helmer,K.P.Jackson, L.Lee, C.A.Miller, E.Rost, R.Sawafta, R.Schuhbank, S.S.M.Wong, S.Yen,and X.Zhu, “Excitation of the 10.957 MeV 0−; T=0 state in 16O by 400 MeV Pro-tons”, Phys.Rev.C, 44, 3 (1991) 1077

27. L.Buchmann, K.Jayamanna, C.D.P.Levy, M.McDonald, R.Ruegg,P.W.Schmor, A.Belov, V.G.Polushkin, and A.N.Zelenski, “A DC optically pumped,polarized H− source”, Nucl. Inst. Meth. (1991), A306 (1991) 413

28. L.Buchmann, “A proton polarimeter for beam energies below 300 keV”, Nucl. Instr.Meth. (1991), A301 (1991) 383


29. J.D’Auria and L. Buchmann, ”Radioactive beams facilities: A status report”, Nucl.Instr. Meth. B56/57 (1991) 516

30. M.Dombsky, J.M.D’Auria, L.Buchmann, H.Sprenger, J.Vincent, P.McNeely, andG.Roy, “Target and ion source development at the TISOL facility at TRIUMF”,Nucl. Instr. Meth., A295 (1990) 291

31. J.M. D’Auria, M.Dombsky, L.Buchmann, and J.S. Vincent, “Studies related to theproduction of an isotopically pure 22Na radioactive target”, Nucl. Instr. Meth.A288 (1990) 354

32. P.McNeely, G.Roy, J.Soukup,J.M.D’Auria, L.Buchmann, M.McDonald, P.W.Schmor,H.Sprenger, and J.Vincent, “The UoA/TRIUMF radioactive beam ECR ion source”,Rev.Sci.Instrum. 61,1 (1990) 273

33. J.M. D’Auria, M. Dombsky, L. Buchmann, J.D. Vincent, and J.D. King, “The pro-posed ISAC facility at TRIUMF”, Nucl. Instr. Meth., B40/41 (1989) 418

34. M. Wiescher, J. Gorres, S. Graff, L.Buchmann, F.-K. Thielemann, ”The hot pp-Chains in Low Metallicity Objects”, Ap. J. 343 (1989) 352

35. L.Lee, T.E.Drake, S.S.M.Wong, D.Frekers, R.E.Azuma, L.Buchmann,A.Galindo-Uribari, J.D.King, R.Schubank, R.Abegg, R.Helmer, K.P.Jackson, C.A.Miller,andS.Yen,”Intermediate-energy proton scattering to the ground and negative paritystates of 40Ca , 90Zr and 208Pb”, Nucl. Phys. A492 (1989) 607

36. L.Lee, T.E.Drake, S.S.M.Wong, D.Frekers, R.E.Azuma, L.Buchmann, A. Galindo-Uribarri, J.D. King, R.Schubank, R.Abegg, R. Helmer, K.P. Jackson, C.A.Miller,andS.Yen, “Inelastic proton scattering to the positive-parity states in 90Zr at 400 MeV”,J.Phys. G, 15 (1989) L91

37. P.McNeely, G.Roy, J.Soukup, J.M.D’Auria, L.Buchmann, M.McDonald, P.W.Schmor,and H.Sprenger, ”An ECR ion source for radioactive beams at TRIUMF”, J.d.Phys.,50 (1989) Cl 807

38. L.Buchmann, J.M.D’Auria, and P.McCorquodale, “Stellar reaction rates of alphacapture on light (N �= Z) Nuclei and their astrophysical implications”, Ap. J.,324(1988) 953

39. L.Lee, T.E.Drake, S.S.M. Wong, D.Frekers, R.E.Azuma, L.Buchmann, A. Galindo-Uribari, J.D.King, R.Schubank, R.Abegg, R.Helmer, K.P.Jackson, C.A. Miller, S.Yen,and H.V. von Geramb, “Intermediate energy proton scattering from 40Ca , 90Zr and208Pb”, Phys. Lett. B, 205 2,3, (1988) 219

40. L.Buchmann, J.M.D’Auria, J.D.King, G.Mackenzie, H.Schneider,R.B.Moore, and C.Rolfs, “An Isol/postaccelerator facility for nuclear astrophysicsat TRIUMF”, Nucl. Instr. Meth., B26 (1987) 151

41. L.Buchmann, T.Mattman, J.M.D’Auria, E.Devita, H.Schneider, A.Otter, H.Sprenger,and P.W.Schmor, “A conceptual design of an ECR source for an Isol facility”, Nucl.Instr. Meth., B26 (1987) 253


42. J.E.Crawford, J.K.P.Lee, R.B.Moore, H.Dautet, F.Buchinger, K.Oxorn, L.Nikkinen,J.M.D’Auria, L.Buchmann, J.Vincent, and J.King, “A proposed radioactive beamfacility at TRIUMF”, Nucl. Instr. Meth. B26 (1987) 128

43. K.Oxorn, J.E.Crawford, H.Dautet, J.K.P.Lee, R.B.Moore, L.Nikkiinen, L.Buchmann,J.M.D’Auria, R.Kokke, A.J.Otter, H.Sprenger, and J.Vincent, “The installation ofa prototype on-line isotope separator at TRIUMF (TISOL)”, Nucl. Instr. Meth.,B26 (1987) 143

44. U.Schroder, A.Redder, C.Rolfs, R.E.Azuma, L.Buchmann, C.Campbell, J.D. King,and T.R. Donoghue, “Astrophysical S Factor of 3H(α, γ)7Li ”, Phys. Lett. B, 1921,2 (1987) 55

45. H.P.Trautvetter, H.W.Becker, U.Heinemann, L.Buchmann, C.Rolfs,F.Kappeler, M.Baumann, H.Freiesleben, H.J.Lutke-Stetzkamp,P.Geltenbort, and F.Gonnenwein, ”Destruction of 26Al in explosive nucleosynthesis”,Z.Phys.A, 323 (1986) 1

46. C.A.Miller, A.Scott, R.Abegg, R.Helmer, K.P.Jackson, M.Whiten, S.Yen, L.Lee,T.E.Drake, D.Frekers, S.S.M.Wong, R.E.Azuma, L.Buchmann, A. Galindo-Uribari,J.D.King, R.Schubank, R.Dymarz, H.V. von Geramb, and C.J.Horowitz, “Largeangle elastic scattering of 200 MeV protons from 208Pb”, Phys. Lett., 169B, 2,3(1986) 166

47. L.Lee, T.E.Drake, L.Buchmann, A.Galindo-Uribarri, R.Schubank, R.J.Sobie, D.R.Gill, B.K.Jennings, N. de Takacsy, “Evidence for the suppression of mul-tiple scattering in12C(π,π′) at low energies”, Phys. Lett. B, 174, 2 (1986) 147

48. L.Buchmann, J.M.D’Auria, G. Mackenzie, H.Schneider, R.B.Moore, “Developmentof a radioactive beams (RB) accelerator using ISOL as asource”, IEEE, Nucl. Sc. 32,5 (1985) 3330

49. L.Buchmann, M.Hilgemeier, A.Krauss, A.Redder, C.Rolfs, H.P. Trautvetter, andT.R. Donoghue, ”The abundance of 26Al in the MgAl cycle”, Nucl. Phys., A415(1984) 93

50. L.Buchmann, H.Baumeister, and C.Rolfs, “The fabrication of 26Al targets”, Nucl.Instr. Meth., B4 (1984) 132

51. P.Schmalbrock, H.W.Becker, L.Buchmann, J.Gorres, C.Rolfs,H.P.Trautvetter, and W.S.Rodney, “Search for γ-ray transitions within the 5LiGroundstate”, Z. Phys. A., 310 (1983), 243

52. J. Gorres, H.W. Becker, L.Buchmann, C.Rolfs, P.Schmalbrock,H.P.Trautvetter,, A.Vlieks, J.W.Hammer, T.R.Donoghue, “Proton-induced directcapture on 21Ne and 22Ne”, Nucl. Phys., A408 (1983), 372

53. P.Schmalbrock, H.W.Becker, L.Buchmann, J.Gorres, K.U.Kettner,W.E.Kieser, H.Krawinkel, C.Rolfs, and H.P.Trautvetter, “Stellar reaction rate of20Ne(α,γ)24Mg”, Nucl. Phys., A398 (1983) 279

54. K.U.Kettner, H.W.Becker, L.Buchmann, J.Gorres, H.Krawinkel, C.Rolfs, P.Schmalbrock,H.P.Trautvetter, and A.Vlieks, “The 4He(12C,γ)16O reaction at stellar energies”, Z.Phys. A, 308 (1982) 73


55. H.W.Becker, L.Buchmann, J.Gorres, K.U.Kettner, H.Krawinkel, C.Rolfs, P.Schmalbrock,H.P.Trautvetter, and A.Vlieks, “A supersonic jet gas target for γ spectroscopy mea-surements”, Nucl. Inst. Meth., 198 (1982) 277

56. H.Krawinkel, H.W.Becker, L.Buchmann, J.Gorres, K.U.Kettner, W.E.Kieser,R.Santo, P.Schmalbrock, H.P.Trautvetter, A.Vlieks, C.Rolfs, J.W. Hammer,R.E.Azuma, W.S.Rodney, “The 3He(α ,γ)7Be reaction and the solar neutrino prob-lem”, Z. Phys. A., 304 (1982) 307

57. L.Buchmann, H.W.Becker, K.U.Kettner, W.E.Kieser, P.Schmalbrock, and C.Rolfs,“Stellar reaction rate of 26Mg(p,γ)27Al ”, Z. Phys. A., 296 (1980) 273

58. K.Elix, H.W.Becker, L.Buchmann, J.Gorres, K.U.Kettner, M.Wiescher, and C.Rolfs,“Search for low-energy resonances in 25Mg(p,γ) 26Al”, Z. Phys. A, 293 (1979) 261

8 Submitted and In Print

1. A. Zyuzin, S.H. Park, L. Buchmann, K.R. Buckley, A.R. Junghans, E.C. Mohrmann,K.A. Snover, T.D. Steiger, and J. Vincent, “The fabrication of metallic 7Be targetswith a small diameter for 7Be(p,γ)8B measurements”, submitted to Nucl. Instr.Meth. B, June 2001

2. A.R. Junghans, E.C. Mohrmann, K.A. Snover, T.D. Steiger, E.G. Adelberger, J.M.Casandjian, H.E. Swanson, L. Buchmann, S.H. Park, A. Zyuzin, “7Be(p,γ)8B” as-trophysical S-factor from precision cross section measurements”, submitted to Phys.Rev. Let., August 2001

3. A.C. Morton, J.C. Chow, J.D. King, R.N. Boyd, N.P.T. Bateman, L. Buchmann,J.M. D’Auria, T. Davinson, M. Dombsky, W. Galster, E. Gete, U. Giesen, C. Iliadis,K.P. Jackson, J. Powell, G. Roy, and A. Shotter, “Beta-delayed particle decay of17Ne”, submitted to Nucl. Phys. A, August 2001

4. P.Tischhauser, R.E. Azuma, L. Buchmann, R. Detwiler, U. Giesen, J. Gorres, M.Heil, J. Hinnefeld, F. Kappeler, J.J. Kolata, H. Schatz, A. Shotter, E. Stech, S.Vouzoukas, and M. Wiescher,“ Elastic α-12 scattering and the 12C(α,γ)16O E2 S-factor”, submitted to Phys. Rev. Let., September 2001

5. D. Anthony, L. Buchmann, P. Bergbusch, J.M. D’Auria, M. Dombsky, U. Giesen,K.P. Jackson, J.D. King, J. Powell, and F.C. Barker, “Beta Delayed Deuteron emis-sion from 6He”, submitted to Phys. Rev. C, September 2001

TRIUMF — RESEARCH PROPOSAL 927 Sheet 1 of 20

Documents

Transcript of TRIUMF — RESEARCH PROPOSAL 927 Sheet 1 of 20