PAC2013 - List of Authors (Portmann, G.J.)

Paper

Title

Page

Pseudo Single Bunch with Adjustable Frequency

285

C. Sun, M.P. Hertlein, J. Kirz, M. Marcus, G.J. Portmann, D. Robin, C. Steier
LBNL, Berkeley, California, USA

We present the concept and results of pseudo single bunch (PSB) operation–a new operational mode at the advanced light source–that can greatly expand the capabilities of synchrotron light sources to carry out dynamics and time-of-flight experiments. In PSB operation, a single electron bunch is displaced transversely from the other electron bunches using a short-pulse, high-repetition-rate kicker magnet. Experiments that require light emitted only from a single bunch can stop the light emitted from the other bunches using a collimator. Other beam lines will only see a small reduction in flux due to the displaced bunch. As a result, PSB eliminates the need to schedule multibunch and timing experiments during different running periods. Furthermore, the time spacing of PSB pulses can be adjusted from milliseconds to microseconds with a novel “kick-and-cancel” scheme, which can significantly alleviate complications of using high-power choppers and substantially reduce the rate of sample damage.

TUOCB2

Successful Completion of the ALS Brightness Upgrade

433

C. Steier, B.J. Bailey, K. Berg, A. Biocca, A.T. Black, P.W. Casey, D. Colomb, R.F. Gunion, N. Li, A. Madur, S. Marks, H. Nishimura, G.C. Pappas, K.V. Petermann, G.J. Portmann, S. Prestemon, A.W. Rawlins, D. Robin, S.L. Rossi, T. Scarvie, D. Schlueter, C. Sun, H. Tarawneh, W. Wan, E.C. Williams
LBNL, Berkeley, California, USA
C. Chen, J. Jin, Y.M. Wen, J. Wu, L. Yin, J.D. Zhang, Q.G. Zhou
SINAP, Shanghai, People's Republic of China

Funding: The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The Advanced Light Source (ALS) at Berkeley Lab is one of the brightest sources for soft x-rays worldwide. A multiyear upgrade of the ALS is underway, which includes new and replacement x-ray beamlines, a replacement of many of the original insertion devices and many upgrades to the accelerator. The accelerator upgrade that affects the ALS performance most directly is the brightness upgrade, which reduced the horizontal emittance from 6.3 nm to 2.0 nm (2.5 nm effective), resulting in one of the lowest horizontal emittances of operating light sources. Magnets for this upgrade were installed in late 2012 and early 2013 followed by successful commissioning and user operation with 2.0 nm horizontal emittance.

Slides TUOCB2 [4.931 MB]

WEYA1

Recent Results from the APEX Project at LBNL

709

F. Sannibale, K.M. Baptiste, C.W. Cork, J.N. Corlett, S. De Santis, L.R. Doolittle, J.A. Doyle, D. Filippetto, G.L. Harris, G. Huang, R. Huang, T.D. Kramasz, S. Kwiatkowski, R.E. Lellinger, V. Moroz, W.E. Norum, C. F. Papadopoulos, G.J. Portmann, H.J. Qian, J.W. Staples, M. Vinco, R.P. Wells, M.S. Zolotorev
LBNL, Berkeley, California, USA
R. Huang
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231
The commissioning at the Lawrence Berkeley National Laboratory (LBNL) of a high-brightness high-repetition rate (MHz-class) photo-gun, based on a normal conducting 186 MHz (VHF-band) RF cavity operating in CW mode, is now completed. The gun has been designed to satisfy the requirements for operating high-repetition rate 4th generation light sources. Test of high quantum efficiency photocathodes with bunches of hundreds pC at MHz repetition rate are now underway. They include, Cs2Te cathodes developed in collaboration with INFN-LASA and multialkali antimonides (CsK2Sb), prepared by a collaborating group at LBNL. The present experimental results and the plan for future activities are presented.

Slides WEYA1 [22.976 MB]

Paper	Title	Page
MOPHO22	Pseudo Single Bunch with Adjustable Frequency	285
	C. Sun, M.P. Hertlein, J. Kirz, M. Marcus, G.J. Portmann, D. Robin, C. Steier LBNL, Berkeley, California, USA
	We present the concept and results of pseudo single bunch (PSB) operation–a new operational mode at the advanced light source–that can greatly expand the capabilities of synchrotron light sources to carry out dynamics and time-of-flight experiments. In PSB operation, a single electron bunch is displaced transversely from the other electron bunches using a short-pulse, high-repetition-rate kicker magnet. Experiments that require light emitted only from a single bunch can stop the light emitted from the other bunches using a collimator. Other beam lines will only see a small reduction in flux due to the displaced bunch. As a result, PSB eliminates the need to schedule multibunch and timing experiments during different running periods. Furthermore, the time spacing of PSB pulses can be adjusted from milliseconds to microseconds with a novel “kick-and-cancel” scheme, which can significantly alleviate complications of using high-power choppers and substantially reduce the rate of sample damage.

TUOCB2	Successful Completion of the ALS Brightness Upgrade	433
	C. Steier, B.J. Bailey, K. Berg, A. Biocca, A.T. Black, P.W. Casey, D. Colomb, R.F. Gunion, N. Li, A. Madur, S. Marks, H. Nishimura, G.C. Pappas, K.V. Petermann, G.J. Portmann, S. Prestemon, A.W. Rawlins, D. Robin, S.L. Rossi, T. Scarvie, D. Schlueter, C. Sun, H. Tarawneh, W. Wan, E.C. Williams LBNL, Berkeley, California, USA C. Chen, J. Jin, Y.M. Wen, J. Wu, L. Yin, J.D. Zhang, Q.G. Zhou SINAP, Shanghai, People's Republic of China
	Funding: The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The Advanced Light Source (ALS) at Berkeley Lab is one of the brightest sources for soft x-rays worldwide. A multiyear upgrade of the ALS is underway, which includes new and replacement x-ray beamlines, a replacement of many of the original insertion devices and many upgrades to the accelerator. The accelerator upgrade that affects the ALS performance most directly is the brightness upgrade, which reduced the horizontal emittance from 6.3 nm to 2.0 nm (2.5 nm effective), resulting in one of the lowest horizontal emittances of operating light sources. Magnets for this upgrade were installed in late 2012 and early 2013 followed by successful commissioning and user operation with 2.0 nm horizontal emittance.
	Slides TUOCB2 [4.931 MB]

WEYA1	Recent Results from the APEX Project at LBNL	709
	F. Sannibale, K.M. Baptiste, C.W. Cork, J.N. Corlett, S. De Santis, L.R. Doolittle, J.A. Doyle, D. Filippetto, G.L. Harris, G. Huang, R. Huang, T.D. Kramasz, S. Kwiatkowski, R.E. Lellinger, V. Moroz, W.E. Norum, C. F. Papadopoulos, G.J. Portmann, H.J. Qian, J.W. Staples, M. Vinco, R.P. Wells, M.S. Zolotorev LBNL, Berkeley, California, USA R. Huang USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231 The commissioning at the Lawrence Berkeley National Laboratory (LBNL) of a high-brightness high-repetition rate (MHz-class) photo-gun, based on a normal conducting 186 MHz (VHF-band) RF cavity operating in CW mode, is now completed. The gun has been designed to satisfy the requirements for operating high-repetition rate 4th generation light sources. Test of high quantum efficiency photocathodes with bunches of hundreds pC at MHz repetition rate are now underway. They include, Cs2Te cathodes developed in collaboration with INFN-LASA and multialkali antimonides (CsK2Sb), prepared by a collaborating group at LBNL. The present experimental results and the plan for future activities are presented.
	Slides WEYA1 [22.976 MB]