IPAC2015 - List of Authors (Du, X.)

Paper	Title	Page
TUXB2	Upgrade of the Unilac for Fair	1281
	L. Groening, A. Adonin, R. M. Brodhage, X. Du, R. Hollinger, O.K. Kester, S. Mickat, A. Orzhekhovskaya, B. Schlitt, G. Schreiber, H. Vormann, C. Xiao GSI, Darmstadt, Germany H. Hähnel, U. Ratzinger, A. Seibel, R. Tiede IAP, Frankfurt am Main, Germany
	The UNIversal Linear Accelerator (UNILAC) at GSI serves as injector for all ion species from protons to uranium since four decades. Its 10⁸ MHz Alvarez type DTL providing acceleration from 1.4 MeV/u to 11.4 MeV/u has suffered from material fatigue. The DTL will be replaced by a completely new section with almost same design parameters, i.e. pulsed current of up to 15 mA of 238U²⁸⁺ at 11.4 MeV/u. A dedicated terminal & LEBT for operation with 238U⁴⁺ is currently constructed. The uranium sources need to be upgraded in order to provide increased beam brilliances and for operation at 3 Hz. In parallel a 70 MeV / 70 mA proton linac based on H-mode cavities is under design and construction. This contribution will also give a brief summary of the overall status of the FAIR project.
	Slides TUXB2 [4.634 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUXB2
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WEPMA017	Alvarez DTL Cavity Design for the UNLAC Upgrade	2786
	X. Du, L. Groening, S. Mickat GSI, Darmstadt, Germany A. Seibel IAP, Frankfurt am Main, Germany
	The 10⁸.4 MHz drift tube linac (DTL) accelerator for GSI’s UNLAC upgrade project is in its initial design stage using CST-MWS code. Optimization criteria for cavity design are effective shunt impedance (ZTT), transit-time factor, and electrical breakdown limit. In geometrical op-timization we have aimed at increase of the energy gain in each RF gap of the DTL cells by maximizing ZTT per peak surface field with special designed tube profile. Mul-ti-pacting probability is evaluated for one gap of typical single cell. For the beta profile design, a code based on VBA macros of CST is developed to perform cell by cell design with pre-optimized 3D tube structures. With this code several beta profile designs are presented and com-pared for the balance of power consumption, ZTT, tank length, and breakdown possibility of the complete cavity. The stability of the field has been taken into account and for this the crossed stem arrangement is assessed. This paper gives a short introduction of the method, presents some important results. Possible countermeas-ures are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMA017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPF027	Ten Gap Model of a New Alvarez DTL Cavity at GSI	3748
	A. Seibel, O.K. Kester IAP, Frankfurt am Main, Germany X. Du, L. Groening, S. Mickat GSI, Darmstadt, Germany
	In order to meet the challenges of the FAIR project at GSI requiring highest beam intensities an upgrade of the existing Universal Linear Accelerator (UNILAC) is planned. The 10⁸ MHz cavities will be replaced by new rf-structures of the same frequency. Simulations are done to improve the rf-properties. The geometry of the drift tubes is to be changed to a smoother curvature to reach a homogeneous surface field distribution and higher shunt impedances. To check the necessity of cooling channels, simulations on the temperature distribution at the drift tubes and stems are conducted. A test bench for low power rf-measurements with a 10 gap aluminum model (scale 1:3) is under construction. The modular mechanical design of the model will allow probing experimentally a wide range of drift tube and stem geometries. With the bead pull method the electrical field distribution will be measured as well as the field stability with respect to parasitic modes. Additionally, appropriate locations along the cavity to place fixed and dynamic rf-frequency tuners will be determined.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF027
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Upgrade of the Unilac for Fair

1281

L. Groening, A. Adonin, R. M. Brodhage, X. Du, R. Hollinger, O.K. Kester, S. Mickat, A. Orzhekhovskaya, B. Schlitt, G. Schreiber, H. Vormann, C. Xiao
GSI, Darmstadt, Germany
H. Hähnel, U. Ratzinger, A. Seibel, R. Tiede
IAP, Frankfurt am Main, Germany

The UNIversal Linear Accelerator (UNILAC) at GSI serves as injector for all ion species from protons to uranium since four decades. Its 10⁸ MHz Alvarez type DTL providing acceleration from 1.4 MeV/u to 11.4 MeV/u has suffered from material fatigue. The DTL will be replaced by a completely new section with almost same design parameters, i.e. pulsed current of up to 15 mA of 238U²⁸⁺ at 11.4 MeV/u. A dedicated terminal & LEBT for operation with 238U⁴⁺ is currently constructed. The uranium sources need to be upgraded in order to provide increased beam brilliances and for operation at 3 Hz. In parallel a 70 MeV / 70 mA proton linac based on H-mode cavities is under design and construction. This contribution will also give a brief summary of the overall status of the FAIR project.

Slides TUXB2 [4.634 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUXB2

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMA017

Alvarez DTL Cavity Design for the UNLAC Upgrade

2786

X. Du, L. Groening, S. Mickat
GSI, Darmstadt, Germany
A. Seibel
IAP, Frankfurt am Main, Germany

The 10⁸.4 MHz drift tube linac (DTL) accelerator for GSI’s UNLAC upgrade project is in its initial design stage using CST-MWS code. Optimization criteria for cavity design are effective shunt impedance (ZTT), transit-time factor, and electrical breakdown limit. In geometrical op-timization we have aimed at increase of the energy gain in each RF gap of the DTL cells by maximizing ZTT per peak surface field with special designed tube profile. Mul-ti-pacting probability is evaluated for one gap of typical single cell. For the beta profile design, a code based on VBA macros of CST is developed to perform cell by cell design with pre-optimized 3D tube structures. With this code several beta profile designs are presented and com-pared for the balance of power consumption, ZTT, tank length, and breakdown possibility of the complete cavity. The stability of the field has been taken into account and for this the crossed stem arrangement is assessed. This paper gives a short introduction of the method, presents some important results. Possible countermeas-ures are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMA017

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPF027

Ten Gap Model of a New Alvarez DTL Cavity at GSI

3748

A. Seibel, O.K. Kester
IAP, Frankfurt am Main, Germany
X. Du, L. Groening, S. Mickat
GSI, Darmstadt, Germany

In order to meet the challenges of the FAIR project at GSI requiring highest beam intensities an upgrade of the existing Universal Linear Accelerator (UNILAC) is planned. The 10⁸ MHz cavities will be replaced by new rf-structures of the same frequency. Simulations are done to improve the rf-properties. The geometry of the drift tubes is to be changed to a smoother curvature to reach a homogeneous surface field distribution and higher shunt impedances. To check the necessity of cooling channels, simulations on the temperature distribution at the drift tubes and stems are conducted. A test bench for low power rf-measurements with a 10 gap aluminum model (scale 1:3) is under construction. The modular mechanical design of the model will allow probing experimentally a wide range of drift tube and stem geometries. With the bead pull method the electrical field distribution will be measured as well as the field stability with respect to parasitic modes. Additionally, appropriate locations along the cavity to place fixed and dynamic rf-frequency tuners will be determined.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF027

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)