CYCLOTRONS 2010 - List of Authors (Servais, T.)

Paper	Title	Page
MOPCP072	Design of IBA Cyclone 11 Cyclotron Magnet	192
	V. Nuttens, M. Abs, W.J.G.M. Kleeven, B. Nactergal, D. Neuvéglise, T. Servais, S. Zaremba IBA, Louvain-la-Neuve, Belgium
	To extend customer choice in the low energy range, IBA is developing the Cyclone 11. It is a fixed energy 11 MeV H⁻ cyclotron for the production of PET isotopes. The cyclotron magnet is based on the well known Cyclone 10/5, with the same yoke dimensions, which is compatible with the IBA self-shielding design. The higher proton energy compared to the 10 MeV machine takes the benefit of the higher PET isotope production yield. This poster presents the Cyclone 10 magnet modifications required to reach 11 MeV. At first, the magnetic field has been raised by a small reduction of the valley depth. Additionally, the main coil current has been increased. The pole edge milling has been used to obtain the isochronous magnetic field shape. Beam optics in the magnet is excellent. Extraction is ensured by means of stripper foils mounted on carousels located at different azimuths allowing for up to eight targets.

MOPCP074	Upgrade of the IBA Cyclone 3D Cyclotron	197
	W.J.G.M. Kleeven, M. Abs, E. Forton, B. Nactergal, D. Neuvéglise, T. Servais, S. Zaremba IBA, Louvain-la-Neuve, Belgium
	There is a need for 15O generator producing a continuous flow of PET tracer without disrupting the schedule of the hospital main cyclotron (usually used for ¹⁸F and ¹¹C production) and to promote new emergency room evaluation of brain stroke and ischemic heart attack in PET centers without access to cyclotron short-lived isotopes. To answer, IBA improves the Cyclone 3D, originally developed for this purpose and accelerating D⁺ ions to more than 3 MeV. In the previous magnet design, vertical focusing is obtained by four straight pole-sectors. The new design has three spiralled pole-sectors. This improves the vertical focusing properties of the machine. Also the main coil and the return yoke are slightly modified. This will increase the extraction energy by about 10% from 3.3 MeV to 3.6 MeV. This new design will improve the transmission in the cyclotron and the extraction efficiency above 80%, using an electrostatic deflector. The goal is to obtain an extracted current of 50 μA with the prototype, then 70 μA for subsequent machines. This represents a doubling of the previous model performance. Results of magnetic field optimization and extraction calculations are presented.

MOPCP075	Cyclotron Vacuum Model and H⁻ Gas Stripping Losses	200
	V. Nuttens, M. Abs, J.L. Delvaux, Y. Jongen, W.J.G.M. Kleeven, L. Medeiros-Romao, M. Mehaudens, T. Servais, T. Vanderlinden, P. Verbruggen IBA, Louvain-la-Neuve, Belgium
	Many proton cyclotrons take the advantage of stripping for the extraction, by accelerating H⁻ ions. However, before extraction, the negative ion beam can suffer losses from stripping by the residual gas. The higher is the pressure, the higher the losses. Moreover, the stripped beam will be stopped on the inner wall of the cyclotron, inducing an additional degassing and increasing the pressure and hence losses in the cyclotron. For high beam current, degassing can be too large compared to the pumping capacity and the beam transmission can drop down to zero. The pressure inside the cyclotron has therefore a large impact on the current that can be extracted from the cyclotron. A simple model has been set up at IBA to determine the vacuum pressure in the hills and in the valleys of the Cyclone 70 cyclotron. The transmission is then computed by integration of the gas stripping cross-section along the ion orbits in the cyclotron. Pressure and transmission provided by the model are in good agreement with experimental data in the ARRONAX Cyclone 70 cyclotron installed in Nantes.

Paper

Title

Page

Design of IBA Cyclone 11 Cyclotron Magnet

192

V. Nuttens, M. Abs, W.J.G.M. Kleeven, B. Nactergal, D. Neuvéglise, T. Servais, S. Zaremba
IBA, Louvain-la-Neuve, Belgium

To extend customer choice in the low energy range, IBA is developing the Cyclone 11. It is a fixed energy 11 MeV H⁻ cyclotron for the production of PET isotopes. The cyclotron magnet is based on the well known Cyclone 10/5, with the same yoke dimensions, which is compatible with the IBA self-shielding design. The higher proton energy compared to the 10 MeV machine takes the benefit of the higher PET isotope production yield. This poster presents the Cyclone 10 magnet modifications required to reach 11 MeV. At first, the magnetic field has been raised by a small reduction of the valley depth. Additionally, the main coil current has been increased. The pole edge milling has been used to obtain the isochronous magnetic field shape. Beam optics in the magnet is excellent. Extraction is ensured by means of stripper foils mounted on carousels located at different azimuths allowing for up to eight targets.

MOPCP074

Upgrade of the IBA Cyclone 3D Cyclotron

197

W.J.G.M. Kleeven, M. Abs, E. Forton, B. Nactergal, D. Neuvéglise, T. Servais, S. Zaremba
IBA, Louvain-la-Neuve, Belgium

There is a need for 15O generator producing a continuous flow of PET tracer without disrupting the schedule of the hospital main cyclotron (usually used for ¹⁸F and ¹¹C production) and to promote new emergency room evaluation of brain stroke and ischemic heart attack in PET centers without access to cyclotron short-lived isotopes. To answer, IBA improves the Cyclone 3D, originally developed for this purpose and accelerating D⁺ ions to more than 3 MeV. In the previous magnet design, vertical focusing is obtained by four straight pole-sectors. The new design has three spiralled pole-sectors. This improves the vertical focusing properties of the machine. Also the main coil and the return yoke are slightly modified. This will increase the extraction energy by about 10% from 3.3 MeV to 3.6 MeV. This new design will improve the transmission in the cyclotron and the extraction efficiency above 80%, using an electrostatic deflector. The goal is to obtain an extracted current of 50 μA with the prototype, then 70 μA for subsequent machines. This represents a doubling of the previous model performance. Results of magnetic field optimization and extraction calculations are presented.

MOPCP075

Cyclotron Vacuum Model and H⁻ Gas Stripping Losses

200

V. Nuttens, M. Abs, J.L. Delvaux, Y. Jongen, W.J.G.M. Kleeven, L. Medeiros-Romao, M. Mehaudens, T. Servais, T. Vanderlinden, P. Verbruggen
IBA, Louvain-la-Neuve, Belgium

Many proton cyclotrons take the advantage of stripping for the extraction, by accelerating H⁻ ions. However, before extraction, the negative ion beam can suffer losses from stripping by the residual gas. The higher is the pressure, the higher the losses. Moreover, the stripped beam will be stopped on the inner wall of the cyclotron, inducing an additional degassing and increasing the pressure and hence losses in the cyclotron. For high beam current, degassing can be too large compared to the pumping capacity and the beam transmission can drop down to zero. The pressure inside the cyclotron has therefore a large impact on the current that can be extracted from the cyclotron. A simple model has been set up at IBA to determine the vacuum pressure in the hills and in the valleys of the Cyclone 70 cyclotron. The transmission is then computed by integration of the gas stripping cross-section along the ion orbits in the cyclotron. Pressure and transmission provided by the model are in good agreement with experimental data in the ARRONAX Cyclone 70 cyclotron installed in Nantes.