IPAC2016 - Classification: 07 Accelerator Technology / T13 Cryogenics

Paper	Title	Page
TUZB02	Challenge of In-vacuum and Cryogenic Undulator Technologies	1080
	J.C. Huang, C.-H. Chang, C.H. Chang, T.Y. Chung, C.-S. Hwang, C.K. Yang, Y.T. Yu NSRRC, Hsinchu, Taiwan H. Kitamura RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	An in-vacuum undulator (IVU) opens the utilization of high-brilliance X-rays in the medium energy storage rings. The development of a short-period undulator with low phase error becomes important to bring X-ray into a new unprecedented brilliant light source in an ultimate storage ring (USR). NdFeB or PrFeB cryogenic permanent magnet undulators (CPMUs) with a short period have been developed worldwide to obtain high brilliance of undulator radiation. A CPMU has high resistance against beam-induced heat load and allow to operate at a narrow gap. In a low emittance or ultimate storage ring, not only the performance of an undulator but the choice of the lattice functions is very important to obtain high bril-liance of synchrotron radiation. The optimum betatron functions and zero dispersion function shall be given for a straight section at IVU/CPMUs. In this paper, the relevant factors and design issues for IVU/CPMU will be discussed. Many technological challenges of a short-period undulator associated with beam induced-heat load, phase errors, and the deformation of in-vacuum girders will also be presented herein.
	Slides TUZB02 [5.204 MB]
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMB046	The Preliminary Conceptual Design of a 2k Cryogneic System for Circular Electron Positron Collider (CEPC)	1199
	Y.P. Liu, L. Bian, R. Ge, R. Han, S.P. Li, M.J. Sang, L.R. Sun, M.F. Xu, R. Ye, J.Q. Zhang, J.H. Zhang, X.Z. Zhang, Z.Z. Zhang IHEP, Beijing, People's Republic of China
	The Circular Electron Positron Collider (CEPC) is a long-term collider project, which will serve as a Higgs Factory and offer a unique opportunity for direct searches for New Physics in the high-energy range far beyond LHC reach [1]. In the frame of this project, a large 2K cryogenic system will be built to provide coolant for superconducting cavities used in booster ring and collider ring. All the superconducting cavities will be working under 2K. This paper will give a brief introduction to the preliminary considerations of this large cryogenic system, including the general layout, heat load estimation, helium refrigerator, schematic flow diagram as well as the main parameters and working process
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMB047	Tracking the Helium Balance in FREIA	1202
	V.G. Ziemann, L. Hermansson Uppsala University, Uppsala, Sweden
	In the FREIA laboratory at Uppsala University we test the super-conducting spoke-cavities for the European Spallation Source. Liquid Helium for cooling the cavities is provided by a liquefaction plant from which also a local user community at the University is served. Recently we encountered a leak due to a faulty valve which went undetected for some time and caused significant loss of Helium. In order to prevent such mishaps in the future we implemented a Helium tracking system that includes detailed accounting of Helium leaving and entering the closed system as well as all volumes containing Helium in the system. We describe the technical implementation and experience to date.
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMB048	Compensation of Beam Induced Effects in LHC Cryogenic Systems	1205
	B. Bradu, E. Blanco Viñuela, G. Ferlin, B. Fernández Adiego, G. Iadarola, P. Plutecki, E. Rogez, A. Tovar González CERN, Geneva, Switzerland
	This paper presents the different control strategies deployed in the LHC cryogenic system in order to compensate the beam induced effects in real-time. LHC beam is inducing important heat loads along the 27 km of beam screens due to synchrotron radiations, image current and electron clouds. These dynamic heat loads disturb significantly the cryogenic plants and automatic compensations are mandatory to operate the LHC at full energy. The LHC beam screens must be maintained in an acceptable temperature range around 20 K to ensure a good beam vacuum, especially during beam injections and energy ramping where the dynamic responses of cryogenic systems cannot be managed with conventional feedback control techniques. Consequently, several control strategies such as feed-forward compensation have been developed and deployed successfully on the machine during 2015 where the beam induced heat loads are forecast in real-time to anticipate their future effects on cryogenic systems. All these developments have been first entirely modeled and simulated dynamically to be validated, allowing then a smooth deployment during the LHC operation.
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMB049	Development of Separator Cooling System for Helium	1209
	W.R. Liao, S.-H. Chang, W.-S. Chiou, P.S.D. Chuang, F. Z. Hsiao, H.C. Li, T.F. Lin, H.H. Tsai NSRRC, Hsinchu, Taiwan
	A helium phase separator with a condenser is under fabrication and assembled at National Synchrotron Radiation Research Centre (NSRRC). The objective of a helium phase separator with its condenser is to separate two-phase helium flow and to re-condense vaporized gaseous helium with a cryocooler of Gifford-McMahon type. We developed a 100 litre (ltr) helium phase separator with a small heat loss as a prototype. The experimental results for the total cooling capacity of the phase separator are 0.73 W at 1.67 bara, which includes the effect of thermal conduction and thermal radiation from the environment. The helium liquefaction rate is 2 ltr/day with a 100 ltr vessel. The mechanism of heat transfer in phase separator was investigated and discussed. This paper presents the experiment of helium liquefaction process of 100 ltr separator with condenser, which was a key component of the helium phase separator.
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMB050	Development of Multi-channel Line for the NSRRC Cryogenic System	1212
	P.S.D. Chuang, S.-H. Chang, W.-S. Chiou, F. Z. Hsiao, H.C. Li, W.R. Liao, T.F. Lin, H.H. Tsai NSRRC, Hsinchu, Taiwan
	For the past few years, the technology of X-ray photon source is getting more and more advanced, more and more countries are now striving to build the biggest synchrotron facility to meet its' need. In Taiwan, the construction of an electron accelerator with the energy of up to 3.5 GeV is constructed to fulfill the strong demands for an X-ray photon source with high brilliance and flux. Thus, to let the TPS be under stable operation, the cryogenic system is therefore very important. The refrigerant of the TPS Cryogenic System is Liquid Helium, to maintain liquid helium in its state, the temperature has to be maintained under 4.5K, however to let liquid helium turn into gas helium, only 20 W is needed. Therefore, the Multi-Channel Line is developed in our system to prevent heat from conduction in and letting liquid helium vaporize. Several mechanical parts have been designed to reduce heat loss and meet its needs, for example the Spacer. The paper presents a design methodology of long multi-channel helium cryogenic transfer lines. It describes some aspects thermo-mechanical calculation, supporting structure and contraction protection.
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Challenge of In-vacuum and Cryogenic Undulator Technologies

1080

J.C. Huang, C.-H. Chang, C.H. Chang, T.Y. Chung, C.-S. Hwang, C.K. Yang, Y.T. Yu
NSRRC, Hsinchu, Taiwan
H. Kitamura
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

An in-vacuum undulator (IVU) opens the utilization of high-brilliance X-rays in the medium energy storage rings. The development of a short-period undulator with low phase error becomes important to bring X-ray into a new unprecedented brilliant light source in an ultimate storage ring (USR). NdFeB or PrFeB cryogenic permanent magnet undulators (CPMUs) with a short period have been developed worldwide to obtain high brilliance of undulator radiation. A CPMU has high resistance against beam-induced heat load and allow to operate at a narrow gap. In a low emittance or ultimate storage ring, not only the performance of an undulator but the choice of the lattice functions is very important to obtain high bril-liance of synchrotron radiation. The optimum betatron functions and zero dispersion function shall be given for a straight section at IVU/CPMUs. In this paper, the relevant factors and design issues for IVU/CPMU will be discussed. Many technological challenges of a short-period undulator associated with beam induced-heat load, phase errors, and the deformation of in-vacuum girders will also be presented herein.

Slides TUZB02 [5.204 MB]

Export •

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

TUPMB046

The Preliminary Conceptual Design of a 2k Cryogneic System for Circular Electron Positron Collider (CEPC)

1199

Y.P. Liu, L. Bian, R. Ge, R. Han, S.P. Li, M.J. Sang, L.R. Sun, M.F. Xu, R. Ye, J.Q. Zhang, J.H. Zhang, X.Z. Zhang, Z.Z. Zhang
IHEP, Beijing, People's Republic of China

The Circular Electron Positron Collider (CEPC) is a long-term collider project, which will serve as a Higgs Factory and offer a unique opportunity for direct searches for New Physics in the high-energy range far beyond LHC reach [1]. In the frame of this project, a large 2K cryogenic system will be built to provide coolant for superconducting cavities used in booster ring and collider ring. All the superconducting cavities will be working under 2K. This paper will give a brief introduction to the preliminary considerations of this large cryogenic system, including the general layout, heat load estimation, helium refrigerator, schematic flow diagram as well as the main parameters and working process

Export •

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

TUPMB047

Tracking the Helium Balance in FREIA

1202

V.G. Ziemann, L. Hermansson
Uppsala University, Uppsala, Sweden

In the FREIA laboratory at Uppsala University we test the super-conducting spoke-cavities for the European Spallation Source. Liquid Helium for cooling the cavities is provided by a liquefaction plant from which also a local user community at the University is served. Recently we encountered a leak due to a faulty valve which went undetected for some time and caused significant loss of Helium. In order to prevent such mishaps in the future we implemented a Helium tracking system that includes detailed accounting of Helium leaving and entering the closed system as well as all volumes containing Helium in the system. We describe the technical implementation and experience to date.

Export •

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

TUPMB048

Compensation of Beam Induced Effects in LHC Cryogenic Systems

1205

B. Bradu, E. Blanco Viñuela, G. Ferlin, B. Fernández Adiego, G. Iadarola, P. Plutecki, E. Rogez, A. Tovar González
CERN, Geneva, Switzerland

This paper presents the different control strategies deployed in the LHC cryogenic system in order to compensate the beam induced effects in real-time. LHC beam is inducing important heat loads along the 27 km of beam screens due to synchrotron radiations, image current and electron clouds. These dynamic heat loads disturb significantly the cryogenic plants and automatic compensations are mandatory to operate the LHC at full energy. The LHC beam screens must be maintained in an acceptable temperature range around 20 K to ensure a good beam vacuum, especially during beam injections and energy ramping where the dynamic responses of cryogenic systems cannot be managed with conventional feedback control techniques. Consequently, several control strategies such as feed-forward compensation have been developed and deployed successfully on the machine during 2015 where the beam induced heat loads are forecast in real-time to anticipate their future effects on cryogenic systems. All these developments have been first entirely modeled and simulated dynamically to be validated, allowing then a smooth deployment during the LHC operation.

Export •

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

TUPMB049

Development of Separator Cooling System for Helium

1209

W.R. Liao, S.-H. Chang, W.-S. Chiou, P.S.D. Chuang, F. Z. Hsiao, H.C. Li, T.F. Lin, H.H. Tsai
NSRRC, Hsinchu, Taiwan

A helium phase separator with a condenser is under fabrication and assembled at National Synchrotron Radiation Research Centre (NSRRC). The objective of a helium phase separator with its condenser is to separate two-phase helium flow and to re-condense vaporized gaseous helium with a cryocooler of Gifford-McMahon type. We developed a 100 litre (ltr) helium phase separator with a small heat loss as a prototype. The experimental results for the total cooling capacity of the phase separator are 0.73 W at 1.67 bara, which includes the effect of thermal conduction and thermal radiation from the environment. The helium liquefaction rate is 2 ltr/day with a 100 ltr vessel. The mechanism of heat transfer in phase separator was investigated and discussed. This paper presents the experiment of helium liquefaction process of 100 ltr separator with condenser, which was a key component of the helium phase separator.

Export •

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

TUPMB050

Development of Multi-channel Line for the NSRRC Cryogenic System

1212

P.S.D. Chuang, S.-H. Chang, W.-S. Chiou, F. Z. Hsiao, H.C. Li, W.R. Liao, T.F. Lin, H.H. Tsai
NSRRC, Hsinchu, Taiwan

For the past few years, the technology of X-ray photon source is getting more and more advanced, more and more countries are now striving to build the biggest synchrotron facility to meet its' need. In Taiwan, the construction of an electron accelerator with the energy of up to 3.5 GeV is constructed to fulfill the strong demands for an X-ray photon source with high brilliance and flux. Thus, to let the TPS be under stable operation, the cryogenic system is therefore very important. The refrigerant of the TPS Cryogenic System is Liquid Helium, to maintain liquid helium in its state, the temperature has to be maintained under 4.5K, however to let liquid helium turn into gas helium, only 20 W is needed. Therefore, the Multi-Channel Line is developed in our system to prevent heat from conduction in and letting liquid helium vaporize. Several mechanical parts have been designed to reduce heat loss and meet its needs, for example the Spacer. The paper presents a design methodology of long multi-channel helium cryogenic transfer lines. It describes some aspects thermo-mechanical calculation, supporting structure and contraction protection.

Export •

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