Capacitive-load isolation technique[1] was proposed to improve the stability and capacitive load ability of the timing detector system in internal target of CSRe. This technique can solve the overshoot and ringing pro...Capacitive-load isolation technique[1] was proposed to improve the stability and capacitive load ability of the timing detector system in internal target of CSRe. This technique can solve the overshoot and ringing problems of the circuit, without affecting its gain and bandwidth. By constructing the circuit model, the cause of the instability of the circuit is analyzed mathematically, and the rationality of the capacitive-load isolation techniques is proved in experiment.展开更多
Laser cooling is the most promising method to achieve high phase-space densities, even crystalline beams for relativistic heavy ion at storage rings[1]. A test laser cooling experiment has been performed with 12C3+ io...Laser cooling is the most promising method to achieve high phase-space densities, even crystalline beams for relativistic heavy ion at storage rings[1]. A test laser cooling experiment has been performed with 12C3+ ions at the CSRe. In this experiment, the 12C3+ ions were produced from an electron cyclotron resonance (ECR) ion source, and due to the residual gas and the injection gases such as CO and CO2, 16O4+ ions will be produced at the same time.展开更多
The Isochronous Mass Spectrometry is a high accurate mass spectrometer. A secondary electrons time detector has been developed and used for mass measurements. Secondary electrons from a thin carbon foil are accelerate...The Isochronous Mass Spectrometry is a high accurate mass spectrometer. A secondary electrons time detector has been developed and used for mass measurements. Secondary electrons from a thin carbon foil are accelerated by an electric field and deflected 180°by a magnetic field onto a micro-channel plate. The time detector has been tested with alpha particles and a time resolution of 197 ps （FWHM） was obtained in the laboratory. A mass resolution around 8×10^-6 for Am/m was achieved by using this time detector in a pilot mass measurement experiment.展开更多
An RF system for the CSRe （cooling storage experimental ring） is designed and manufactured domestically. The present paper mainly describes the RF system design in five main sections： ferrite ring, RF cavity, RF ge...An RF system for the CSRe （cooling storage experimental ring） is designed and manufactured domestically. The present paper mainly describes the RF system design in five main sections： ferrite ring, RF cavity, RF generator, low level system and cavity cooling. The cavity is based on a type of coaxial resonator which is shorted at the end with one gap and loaded with domestic ferrite rings. The RF generator is designed in the push-pull mode and the low level control system is based on a DSP＋FGPA＋DDS＋USB interface and has three feedback loops. Finally we give the results of the measurement on our system.展开更多
The 400 MeV/u 12C6＋ ion beam was successfully cooled by the intensive electron beam near 1 A in CSRe.The momentum cooling time was estimated near 15 s.The cooling force was measured in the cases of difierent electron...The 400 MeV/u 12C6＋ ion beam was successfully cooled by the intensive electron beam near 1 A in CSRe.The momentum cooling time was estimated near 15 s.The cooling force was measured in the cases of difierent electron beam profiles,and the difierent angles between the ion beam and electron beam.The lifetime of the ion beam in CSRe was over 80 h.The dispersion in the cooling section was confirmed as positive close to zero.The beam sizes before cooling and after cooling were measured by the moving screen.The beam diameter after cooling was about 1 mm.The bunch length was measured with the help of the signals from the beam position monitor.The difiusion was studied in the absence of the electron beam.展开更多
The operational frequency range of RF system at HIRFL-CSRe (cooling storage experimental ring) is 0.5-2 MHz, and it works in fundamental and second harmonic. It includes five sections: ferrite ring loaded RF cavity, R...The operational frequency range of RF system at HIRFL-CSRe (cooling storage experimental ring) is 0.5-2 MHz, and it works in fundamental and second harmonic. It includes five sections: ferrite ring loaded RF cavity, RF generator, low-level system, computer system and cavity cooling. The cavity is based on the coaxial resonator type which is short at the terminal with one gap and loaded with domestic ferrite rings. The RF generator is designed in a push-pull mode. The low-level control system is based on PID, DSP, FPGA and DDS9854+USB interface and has three feedback loops. This RF system is designed independently and manufactured domestically. For the first time, it realized the pulse modulation, variable harmonic and CW operational modes. The maximum output power is up to 70 kW and the 10 kV RF voltage is used to capture the irradiative beam and decelerate the beam from 400 to 30 MeV/u.展开更多
The stability of the magnetic fields is crucial for the precision experiments conducted at the experimental Cooler Storage Ring CSRe.From 2016,sudden changes of dB=B>10−4 of CSRe dipole magnetic fields happened irr...The stability of the magnetic fields is crucial for the precision experiments conducted at the experimental Cooler Storage Ring CSRe.From 2016,sudden changes of dB=B>10−4 of CSRe dipole magnetic fields happened irregularly which made the precision mass measurements at CSRe difficult to proceed.Therefore,a monitoring system have been built and the instabilities of the power supply and field strengths of the CSRe dipole magnets have been investigated in 2017.展开更多
文摘Capacitive-load isolation technique[1] was proposed to improve the stability and capacitive load ability of the timing detector system in internal target of CSRe. This technique can solve the overshoot and ringing problems of the circuit, without affecting its gain and bandwidth. By constructing the circuit model, the cause of the instability of the circuit is analyzed mathematically, and the rationality of the capacitive-load isolation techniques is proved in experiment.
基金National Natural Science Foundation of China(11504388), West Light Doctoral Foundation of Chinese Academy of Sciences
文摘Laser cooling is the most promising method to achieve high phase-space densities, even crystalline beams for relativistic heavy ion at storage rings[1]. A test laser cooling experiment has been performed with 12C3+ ions at the CSRe. In this experiment, the 12C3+ ions were produced from an electron cyclotron resonance (ECR) ion source, and due to the residual gas and the injection gases such as CO and CO2, 16O4+ ions will be produced at the same time.
基金Supported by National Natural Science Foundation of China (10635080, 10221003)State Key Development Program of BasicsResearch of China (2007CB815000)Knowledge Innovation Project of Chinese Academy of Sciences (CXTD-J2005-1, KJCX2-SWN18)
文摘The Isochronous Mass Spectrometry is a high accurate mass spectrometer. A secondary electrons time detector has been developed and used for mass measurements. Secondary electrons from a thin carbon foil are accelerated by an electric field and deflected 180°by a magnetic field onto a micro-channel plate. The time detector has been tested with alpha particles and a time resolution of 197 ps （FWHM） was obtained in the laboratory. A mass resolution around 8×10^-6 for Am/m was achieved by using this time detector in a pilot mass measurement experiment.
文摘An RF system for the CSRe （cooling storage experimental ring） is designed and manufactured domestically. The present paper mainly describes the RF system design in five main sections： ferrite ring, RF cavity, RF generator, low level system and cavity cooling. The cavity is based on a type of coaxial resonator which is shorted at the end with one gap and loaded with domestic ferrite rings. The RF generator is designed in the push-pull mode and the low level control system is based on a DSP＋FGPA＋DDS＋USB interface and has three feedback loops. Finally we give the results of the measurement on our system.
文摘The 400 MeV/u 12C6＋ ion beam was successfully cooled by the intensive electron beam near 1 A in CSRe.The momentum cooling time was estimated near 15 s.The cooling force was measured in the cases of difierent electron beam profiles,and the difierent angles between the ion beam and electron beam.The lifetime of the ion beam in CSRe was over 80 h.The dispersion in the cooling section was confirmed as positive close to zero.The beam sizes before cooling and after cooling were measured by the moving screen.The beam diameter after cooling was about 1 mm.The bunch length was measured with the help of the signals from the beam position monitor.The difiusion was studied in the absence of the electron beam.
文摘The operational frequency range of RF system at HIRFL-CSRe (cooling storage experimental ring) is 0.5-2 MHz, and it works in fundamental and second harmonic. It includes five sections: ferrite ring loaded RF cavity, RF generator, low-level system, computer system and cavity cooling. The cavity is based on the coaxial resonator type which is short at the terminal with one gap and loaded with domestic ferrite rings. The RF generator is designed in a push-pull mode. The low-level control system is based on PID, DSP, FPGA and DDS9854+USB interface and has three feedback loops. This RF system is designed independently and manufactured domestically. For the first time, it realized the pulse modulation, variable harmonic and CW operational modes. The maximum output power is up to 70 kW and the 10 kV RF voltage is used to capture the irradiative beam and decelerate the beam from 400 to 30 MeV/u.
文摘The stability of the magnetic fields is crucial for the precision experiments conducted at the experimental Cooler Storage Ring CSRe.From 2016,sudden changes of dB=B>10−4 of CSRe dipole magnetic fields happened irregularly which made the precision mass measurements at CSRe difficult to proceed.Therefore,a monitoring system have been built and the instabilities of the power supply and field strengths of the CSRe dipole magnets have been investigated in 2017.
