A combined unit, which has the ability to measure the current and emittance of the high intensity direct current（DC）ion beam, is developed at Peking University（PKU）. It is a multi-slit single-wire（MSSW）-type bea...A combined unit, which has the ability to measure the current and emittance of the high intensity direct current（DC）ion beam, is developed at Peking University（PKU）. It is a multi-slit single-wire（MSSW）-type beam emittance meter combined with a water-cooled Faraday Cup, named high intensity beam emittance measurement unit-6（HIBEMU-6）. It takes about 15 seconds to complete one measurement of the beam current and its emittance. The emittance of a 50-mA@50-kV DC proton beam is measured.展开更多
This paper describes a long-term operation of the 2.45-GHz microwave proton source at Peking University. The DC proton beam of 50–55 mA with energy of 35 keV has been run for 306 hours continuously. Total beam availa...This paper describes a long-term operation of the 2.45-GHz microwave proton source at Peking University. The DC proton beam of 50–55 mA with energy of 35 keV has been run for 306 hours continuously. Total beam availability,defined as 35-keV beam-on time divided by elapsed time, is higher than 99%. Water cooling machine failures cause all the downtime, and no plasma generator failure or high voltage breakdown is observed. The longest uninterrupted run time is122 hours.展开更多
The stability and reliability of an ion source and its beam availability are extremely significant for any accelerator,especially for those high current long term CW operation ones like ADS. Although the first high qu...The stability and reliability of an ion source and its beam availability are extremely significant for any accelerator,especially for those high current long term CW operation ones like ADS. Although the first high quality 306-hours continuous wave（CW） operating curve at 50 m A@35 ke V has been successfully obtained with a standard compact 2.45 GHz ECR ion source at Peking University（PKU）, but the uncertainties that caused beam trips before are unacceptable during an accelerator real operation and should be eliminated. Meanwhile, no permission will be given when the beam power is upgraded from 50 m A@35 ke V to 50 m A@50 ke V. To improve the PKU CW proton source quality, several upgrades were done recently. After those improvements, a new long term CW proton beam experiment at 50 m A@50 ke V was carried out in June 2016. The total running time is 300.5 hours, including near 6 hours ion source preparation and 294 hours non-disturb continuous operation. Within the continuous 13 days operation, no beam-off happened, no spark was observed,no beam drop appeared, no interrupting action was needed, and only a few beam fluctuations caused by the air conditional failure occurred. Beam availability and reliability within the 294 hours is 100%. The root-mean-square（RMS） emittance of this 50 m A@50 ke V CW proton beam is about 0.186 π.mm.mrad. A careful inspection of the ion source was done after this long term operation and no obvious damage was found. The restart experimental results obtained after the ion source inspection prove the high repeatability of PKU PMECRIS. In addition, a 130-m A H＋beam was obtained at 50 k V with duty factor of 10%（100 Hz/1 ms） with this source. Details will be presented in this paper.展开更多
High current hydrogen molecular ion beam is obtained with a specially designed stainless steel liner permanent magnet2.45-GHz electron–cyclotron resonance（ECR） ion source（PMECR II） at Peking University（PKU）. To...High current hydrogen molecular ion beam is obtained with a specially designed stainless steel liner permanent magnet2.45-GHz electron–cyclotron resonance（ECR） ion source（PMECR II） at Peking University（PKU）. To further understand the physics of the hydrogen generation process inside a plasma chamber, theoretical and experimental investigations on the liner material of the plasma chamber in different running conditions are carried out. Several kinds of materials, stainless steel（SS）, tantalum（Ta）, quartz, and aluminum（Al） are selected in our study. Experimental results show that stainless steel and tantalum are much better than others in H~＋_2 generation. During the experiment, an increasing trend in H~＋_2 fraction is observed with stainless steel liner after O_2 discharge inside the ion source. Surface analyses show that the roughness change on the surface after O_2 discharge may be responsible for this phenomenon. After these studies, the pure current of H~＋_2 ions can reach 42.3 mA with a fraction of 52.9%. More details are presented in this paper.展开更多
Optical emission spectroscopy（OES）, as a simple in situ method without disturbing the plasma, has been performed for the plasma diagnosis of a 2.45 GHz permanent magnet electron cyclotron resonance（PMECR） ion sour...Optical emission spectroscopy（OES）, as a simple in situ method without disturbing the plasma, has been performed for the plasma diagnosis of a 2.45 GHz permanent magnet electron cyclotron resonance（PMECR） ion source at Peking University（PKU）. A spectrum measurement platform has been set up with the quartz-chamber electron cyclotron resonance（ECR） ion source [Patent Number： ZL 201110026605.4] and experiments were carried out recently. The electron temperature and electron density inside the ECR plasma chamber have been measured with the method of line intensity ratio of noble gas. Hydrogen plasma processes inside the discharge chamber are discussed based on the diagnostic results. What is more, the superiority of the method of line intensity ratio of noble gas is indicated with a comparison to line intensity ratio of hydrogen. Details will be presented in this paper.展开更多
基金Project supported by the National Basic Research Program of China(Grant No.2014CB845502)the National Natural Science Foundation of China(Grant No.91126004)
文摘A combined unit, which has the ability to measure the current and emittance of the high intensity direct current（DC）ion beam, is developed at Peking University（PKU）. It is a multi-slit single-wire（MSSW）-type beam emittance meter combined with a water-cooled Faraday Cup, named high intensity beam emittance measurement unit-6（HIBEMU-6）. It takes about 15 seconds to complete one measurement of the beam current and its emittance. The emittance of a 50-mA@50-kV DC proton beam is measured.
基金Project supported by the National Basic Research Program of China(Grant No.2014CB845502)the National Natural Science Foundation of China(Grant No.91126004)
文摘This paper describes a long-term operation of the 2.45-GHz microwave proton source at Peking University. The DC proton beam of 50–55 mA with energy of 35 keV has been run for 306 hours continuously. Total beam availability,defined as 35-keV beam-on time divided by elapsed time, is higher than 99%. Water cooling machine failures cause all the downtime, and no plasma generator failure or high voltage breakdown is observed. The longest uninterrupted run time is122 hours.
基金Project supported by the National Basic Research Program of China(Grant No.2014CB845502)the National Natural Science Foundation of China(Grant No.11575013)
文摘The stability and reliability of an ion source and its beam availability are extremely significant for any accelerator,especially for those high current long term CW operation ones like ADS. Although the first high quality 306-hours continuous wave（CW） operating curve at 50 m A@35 ke V has been successfully obtained with a standard compact 2.45 GHz ECR ion source at Peking University（PKU）, but the uncertainties that caused beam trips before are unacceptable during an accelerator real operation and should be eliminated. Meanwhile, no permission will be given when the beam power is upgraded from 50 m A@35 ke V to 50 m A@50 ke V. To improve the PKU CW proton source quality, several upgrades were done recently. After those improvements, a new long term CW proton beam experiment at 50 m A@50 ke V was carried out in June 2016. The total running time is 300.5 hours, including near 6 hours ion source preparation and 294 hours non-disturb continuous operation. Within the continuous 13 days operation, no beam-off happened, no spark was observed,no beam drop appeared, no interrupting action was needed, and only a few beam fluctuations caused by the air conditional failure occurred. Beam availability and reliability within the 294 hours is 100%. The root-mean-square（RMS） emittance of this 50 m A@50 ke V CW proton beam is about 0.186 π.mm.mrad. A careful inspection of the ion source was done after this long term operation and no obvious damage was found. The restart experimental results obtained after the ion source inspection prove the high repeatability of PKU PMECRIS. In addition, a 130-m A H＋beam was obtained at 50 k V with duty factor of 10%（100 Hz/1 ms） with this source. Details will be presented in this paper.
基金supported by the National Natural Science Foundation of China(Grant Nos.11175009 and 11575013)
文摘High current hydrogen molecular ion beam is obtained with a specially designed stainless steel liner permanent magnet2.45-GHz electron–cyclotron resonance（ECR） ion source（PMECR II） at Peking University（PKU）. To further understand the physics of the hydrogen generation process inside a plasma chamber, theoretical and experimental investigations on the liner material of the plasma chamber in different running conditions are carried out. Several kinds of materials, stainless steel（SS）, tantalum（Ta）, quartz, and aluminum（Al） are selected in our study. Experimental results show that stainless steel and tantalum are much better than others in H~＋_2 generation. During the experiment, an increasing trend in H~＋_2 fraction is observed with stainless steel liner after O_2 discharge inside the ion source. Surface analyses show that the roughness change on the surface after O_2 discharge may be responsible for this phenomenon. After these studies, the pure current of H~＋_2 ions can reach 42.3 mA with a fraction of 52.9%. More details are presented in this paper.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11175009 and 11575013)
文摘Optical emission spectroscopy（OES）, as a simple in situ method without disturbing the plasma, has been performed for the plasma diagnosis of a 2.45 GHz permanent magnet electron cyclotron resonance（PMECR） ion source at Peking University（PKU）. A spectrum measurement platform has been set up with the quartz-chamber electron cyclotron resonance（ECR） ion source [Patent Number： ZL 201110026605.4] and experiments were carried out recently. The electron temperature and electron density inside the ECR plasma chamber have been measured with the method of line intensity ratio of noble gas. Hydrogen plasma processes inside the discharge chamber are discussed based on the diagnostic results. What is more, the superiority of the method of line intensity ratio of noble gas is indicated with a comparison to line intensity ratio of hydrogen. Details will be presented in this paper.
