J. R. Alonso

Performance specifications for proton medical facility

Performance specifications of technical components of a modern proton radiotherapy facility are presented. The technical items specified include: the accelerator; the beam transport system including rotating gantry; the treatment beamline systems including beam scattering, beam scanning, and dosimetric instrumentation; and an integrated treatment and accelerator control system. Also included are treatment ancillary facilities such as diagnostic tools, patient positioning and alignment devices, and treatment planning systems. The facility specified will accommodate beam scanning enabling the three-dimensional conformal therapy deliver .

Magnetic moment of proton drip-line nucleus 9C

Abstract The magnetic moment of the proton drip-line nucleus 9 C (I π = 3 2 − , T 1 2 =126 ms ) has been measured for the first time, using the β-NMR detection technique with polarized radioactive beams. The measured value for the magnetic moment is |μ( 9 C )| = 1.3914±0.0005 μ N . The deduced spin expectation value 〈σ〉 of 1.44 is unusually larger than any other ones of even-odd nuclei.

High Purity Radioactive Beams at the Bevalac

Peripheral nuclear fragmentation reactions of primary Bevalac heavy ion beams are used to produce secondary beams of radioactive nuclei. The large cross section and small deflection of the projectile fragments lead to high production and delivery efficiency for these beams. Dispersive beam transport allows good separation and purification of the desired secondary beams. 11C and 19Ne beams of high purity and good intensity (almost 0.2% of the primary beam current) are presently being used for biomedical experiments.

Observation of spin polarization of projectile fragments from 106 A MeV 40Ca+Au collisions☆

Abstract Spin polarization of projectile fragments 37 K and 39 Ca has been observed in 106 A MeV 40 Ca+ 197 Au collisions n ear the grazing angle. The fragment polarization was determined to be positive for points on the high momentum side of the distribution and negative for points on the low momentum side. At the highest energy, the spin polarization follows the same systematics observed at much lower energies, where it is believed that very different reaction mechanisms dominate. A simple fragmentation model explained the observed momentum dependence of the polarization quite well.

Fully Stripped Heavy Ion Yield vs Energy for Xe and au Ions

The Bevalac is now capable of accelerating U-238 ions to approximately 1 GeV/amu and measurements have shown that fully stripped U-238 ions are produced with good yield at these energies. However, knowing the stripping yields at different energies for U-238 does not allow an accurate prediction for other, lower Z projectiles. Consequently, extensive stripping yield measurements were made for Au-197 and Xe-139 ions. In addition to the stripping measurements from the direct Bevalac beam, pickup measurements were also made with specially prepared bare, one electron, and two electron ions. Since many research groups are considering heavy ion storage rings and/or synchrotrons, the pickup cross section for bare ions is important to estimate beam lifetime in terms of the average machine vacuum. Since the Mylar target provides a pickup probability similar to air, a preliminary analysis of the Xe/sup 54 +/ and U/sup 92 +/ data are presented along with predictions for other ions ranging down to Fe/sup 26 +/. 11 refs., 3 figs., 1 tab.

Magnetic moments of proton drip-line nuclei13O and9C

The magnetic moments of the proton drip-line nuclei13O(Iπ = 3/2−,T1/2 = 8.6 ms) and 9C(Iπ = 3/2−,T1/2 = 126 ms) have been determined for the first time through the combined techniques of polarized radioactive nuclear beams andβ-NMR detection. The observed magnetic moments are ¦μ(13O)¦ = 1.3891 ±0.0003μN and ¦μ(9C)¦ = 1.3914 ±0.0005μN. Spin expectation values 〈σ〉 are deduced to be 0.76 and 1.44 for13O and9C, respectively. While the 〈σ〉 of13O is consistent with the systematics from isospinT= 1/2 mirror pairs, the 〈σ〉 of9C is unusually large, even far larger than the single particle value, 〈σ〉 = 1.

Technologies for Delivery of Proton and Ion Beams for Radiotherapy

Recent developments for the delivery of proton and ion beam therapy have been significant, and a number of technological solutions now exist for the creation and utilisation of these particles for the treatment of cancer. In this paper we review the historical development of particle accelerators used for external beam radiotherapy and discuss the more recent progress towards more capable and cost-effective sources of particles.

High energy heavy ions: techniques and applications

Abstract Pioneering work at the Bevalac has given significant insight into the field or relativistic heavy ions, both in the development of techniques for acceleration and delivery of these beams as well as in many novel areas of applications. This paper will outline our experiences at the Bevalac; ion sources, low velocity acceleration, matching to the synchrotron booster, and beam delivery. Applications discussed will include the observation of new effects in central nuclear collisions, production of beams of exotic short-lived (down to 1 μs) isotopes through peripheral nuclear collisions, atomic physics with hydrogen-like uranium ions, effects of heavy “cosmic rays” on satellite equipment, and an ongoing cancer radiotherapy program with heavy ions.

QUADRUPOLE MOMENT OF THE PROTON DRIP-LINE NUCLIDE 13O

Abstract The quadrupole moment of the proton drip-line nuclide 13O(Iπ=3/2−,T=3/2,T1/2=8.6 ms) has been determined for the first time by detecting its β-NQR signal following the production of polarized 13O through the projectile fragmentation process in the 16O + Be collision. The quadrupole moment has been determined to be |Q(13O)|=11.0±1.3 mb. The present result together with the quadrupole moment of its mirror partner 13B is compared with the theoretical values obtained by the shell model code, OXBASH, and by the Hartree-Fock calculation with its single proton separation energy taken into account.

Electromagnetic moments of short lived beta emitters F-21, Mg-23, Si-27 and Ca-39

The β-NMR spectra of 21F, 23Mg, 27Si and 39Ca which were produced in heavy ion collisions and implanted in various crystals have been observed. The magnetic moments of 21F and 27Si were determined to be |μ(21F)| = 3.9194 ± 0.0012 μN and |μ(27Si)| = 0.8653 ± 0.0003 μN, respectively. The electric quadrupole coupling constants were determined for the first time to be |eqQ(21F in MgF2)/h|= 9.94 ± 0.09 MHz, |eqQ(23Mg in MgF2)/h|= 1.96 ± 0.06 MHz, |eqQ(27Si in Al2O3)/h|= 1.90 ± 0.12 MHz, |eqQ(39Ca in CaCO3)/h|= 0.60 ± 0.04 MHz. From the present eqQ/h, the Q moments were deduced as |Q(21F)|= 110 ± 22 mb, |Q(23Mg)|= 114 ± 3 mb, |Q(27Si)|= 60 ± 13 mb and |Q(39Ca)|= 36± 7 mb. The present data were compared with the theoretical values obtained by the OXBASH shell model code.