High-energy photon source(HEPS) is a 6 GeV ultralow emittance storage ring light source to be built in Beijing, China. Both the horizontal and vertical beam sizes of the HEPS storage ring are below 10 lm. It is a chal...High-energy photon source(HEPS) is a 6 GeV ultralow emittance storage ring light source to be built in Beijing, China. Both the horizontal and vertical beam sizes of the HEPS storage ring are below 10 lm. It is a challenge to measure such a small beam size in both directions. To this end, measurement by a Kirkpatrick–Baez(KB) mirror imaging system was evaluated. A test KB system for the Shanghai Synchrotron Radiation Facility storage ring was designed and tested. Two crossed cylindrical mirrors were used to image the dipole source point. Both mirrors can be moved in and out so that the monitor is interchangeable with the original X-ray pinhole monitor. The aberration and point spread function, which would cause image blur, were evaluated. A beam-based calibration scheme was used by varying the beam size with different quadrupole settings and fitting them with the corresponding theoretical values.We updated the original X-ray camera with a new camera having a 5-lm-thick LuAG/Ce scintillator, and the imaging result shows greatly decreased image blur.展开更多
A 16-pole superconducting multipole wiggler with a large gap of 68 mm was designed and fabricated to serve as a multipole wiggler for HEPS-TF.The wiggler consists of 16 pairs of NbTi superconducting coils with a perio...A 16-pole superconducting multipole wiggler with a large gap of 68 mm was designed and fabricated to serve as a multipole wiggler for HEPS-TF.The wiggler consists of 16 pairs of NbTi superconducting coils with a period length of 170 mm,and its maximum peak field is 2.6 Tesla.In magnet design,magnet poles were optimized.Furthermore,the Lorentz force on the coils and electromagnetic force between the upper and lower halves were computed and analyzed along with the stored energy and inductance at different currents.To enhance the critical current of the magnet coil,all the pole coils selected for the magnet exhibited excellent performance,and appropriate prestress derived from the coil force analysis was applied to the pole coils during magnet assembly.The entire magnet structure was immersed in 4.2-K liquid helium in the cryostat cooled solely by four two-stage cryocoolers,and the performance test of the superconducting wiggler was appropriately completed.Based on the measured results,the first and second field integrals on the axis of the superconducting wiggler were significantly improved at different field levels after the compensation of the corrector coils.Subsequently,the wiggler was successfully installed in the storage ring of BEPCII operation with beams.展开更多
文摘High-energy photon source(HEPS) is a 6 GeV ultralow emittance storage ring light source to be built in Beijing, China. Both the horizontal and vertical beam sizes of the HEPS storage ring are below 10 lm. It is a challenge to measure such a small beam size in both directions. To this end, measurement by a Kirkpatrick–Baez(KB) mirror imaging system was evaluated. A test KB system for the Shanghai Synchrotron Radiation Facility storage ring was designed and tested. Two crossed cylindrical mirrors were used to image the dipole source point. Both mirrors can be moved in and out so that the monitor is interchangeable with the original X-ray pinhole monitor. The aberration and point spread function, which would cause image blur, were evaluated. A beam-based calibration scheme was used by varying the beam size with different quadrupole settings and fitting them with the corresponding theoretical values.We updated the original X-ray camera with a new camera having a 5-lm-thick LuAG/Ce scintillator, and the imaging result shows greatly decreased image blur.
文摘A 16-pole superconducting multipole wiggler with a large gap of 68 mm was designed and fabricated to serve as a multipole wiggler for HEPS-TF.The wiggler consists of 16 pairs of NbTi superconducting coils with a period length of 170 mm,and its maximum peak field is 2.6 Tesla.In magnet design,magnet poles were optimized.Furthermore,the Lorentz force on the coils and electromagnetic force between the upper and lower halves were computed and analyzed along with the stored energy and inductance at different currents.To enhance the critical current of the magnet coil,all the pole coils selected for the magnet exhibited excellent performance,and appropriate prestress derived from the coil force analysis was applied to the pole coils during magnet assembly.The entire magnet structure was immersed in 4.2-K liquid helium in the cryostat cooled solely by four two-stage cryocoolers,and the performance test of the superconducting wiggler was appropriately completed.Based on the measured results,the first and second field integrals on the axis of the superconducting wiggler were significantly improved at different field levels after the compensation of the corrector coils.Subsequently,the wiggler was successfully installed in the storage ring of BEPCII operation with beams.
