arXiv subjects

James Lackey

Publications and source records attributed to James Lackey.

3 recordsLinked to original sources

arXiv2005

Study Report of the Booster Transition Jump System

There are more than 15 years since the transition-jump system (TJS) was installed. Because of the quad steering, which is caused by the beam not being well centered through all the gamma-T quads, the TJS has never been used in the operation. Based upon the recent calculation, the short 12 gamma-T quad had the worst offset in the vertical direction, and it was lowered 4 mm. Afterwards, the orbit error caused by the gamma-T quad steering has been largely removed, and this encourages our efforts of commissioning the TJS to reach its design goal.

physics.acc-ph↗

arXiv2005

Booster 6-GeV Study

Since a wider aperture has been obtained along the Booster beam line, this opens the opportunity for Booster running a higher intensity beam than ever before. Sooner or later, the available RF accelerating voltage will become a new limit for the beam intensity. Either by increasing the RFSUM or by reducing the accelerating rate can achieve the similar goal. The motivation for the 6-GeV study is to gain the relative accelerating voltage via a slower acceleration.

physics.acc-ph↗

arXiv2005

Reshape of the Bunch-by-bunch BPM Signal to a Turn-by-turn Matrix during the Fast RF Frequency-sweeping Time in Booster

The bunch-by-bunch BPM signal array has to be reshaped into a turn-by-turn (TBT) matrix in order to make the TBT beam position information of a single bunch available for further data analysis, such as via the Fourier transform to obtain the synchrotron tune and betatron tune, etc. Since the RF frequency sweeps more than 10 MHz in the first 8 ms of a Booster cycle, the revolution time decreases more than 20%. The number of data points for each Booster turn (BT) should be varied in the same pace with the revolution time since the sampling rate of a digital oscilloscope is usually fixed. And this can be done by pre-determining the relationship between the RF frequency and the time in a cycle via the curve fit.

physics.acc-ph↗