The beam horizontal orbit at Hefei Light Source(HLS)was drifting all along while the storage ring was operating.To study this phenomenon,the displacement and the temperature variation of the BPM chamber were measured....The beam horizontal orbit at Hefei Light Source(HLS)was drifting all along while the storage ring was operating.To study this phenomenon,the displacement and the temperature variation of the BPM chamber were measured.By analyzing the measurement results,the main reason that explained the drifting phenomenon was found. The vacuum chamber following the dipole magnets was heated by the synchrotron light,which caused the increasing of the chamber surface temperature.The variation of the chamber temperature was the main reason why the BPM chamber held the horizontal displacement.To suppress the orbit drifting,a compensation method of BPM movement was proposed and its experimental results were given.展开更多
The fiber Bragg grating （FBG） sensing technology was used to monitor the situation of a crevice of the continuous beam joint and rails near rail expansion devices on a viaduct of the urban railway. The monitoring it...The fiber Bragg grating （FBG） sensing technology was used to monitor the situation of a crevice of the continuous beam joint and rails near rail expansion devices on a viaduct of the urban railway. The monitoring items consisted of the rail temperature, rail displacement, viaduct beam displacement, and strain of sliding rail in the rail expansion device section. The strain sensor was a prefabricate FBG strain gauge, the displacement sensor with different scales used an FBG stress ring, and the FBG of the temperature sensor was pre-drawn and fixed in a metal tube. Compensation sensors were used to balance environmental temperature changes. All FBGs were suspended adhered, therefore the chirped phenomenon of the FBG reflection peak was avoided, and the measurement accuracy was improved. The monitoring results matched to the manual test and theoretical estimation.展开更多
文摘The beam horizontal orbit at Hefei Light Source(HLS)was drifting all along while the storage ring was operating.To study this phenomenon,the displacement and the temperature variation of the BPM chamber were measured.By analyzing the measurement results,the main reason that explained the drifting phenomenon was found. The vacuum chamber following the dipole magnets was heated by the synchrotron light,which caused the increasing of the chamber surface temperature.The variation of the chamber temperature was the main reason why the BPM chamber held the horizontal displacement.To suppress the orbit drifting,a compensation method of BPM movement was proposed and its experimental results were given.
文摘The fiber Bragg grating （FBG） sensing technology was used to monitor the situation of a crevice of the continuous beam joint and rails near rail expansion devices on a viaduct of the urban railway. The monitoring items consisted of the rail temperature, rail displacement, viaduct beam displacement, and strain of sliding rail in the rail expansion device section. The strain sensor was a prefabricate FBG strain gauge, the displacement sensor with different scales used an FBG stress ring, and the FBG of the temperature sensor was pre-drawn and fixed in a metal tube. Compensation sensors were used to balance environmental temperature changes. All FBGs were suspended adhered, therefore the chirped phenomenon of the FBG reflection peak was avoided, and the measurement accuracy was improved. The monitoring results matched to the manual test and theoretical estimation.
