Application of vibration wire measurement technology to pre-alignment units of High Energy Photon Source booster

Fig. 2. Vibration wire magnetic center measurement system of pre-alignment unit of booster

Fig. 3. Schematic diagram of measuring methods for horizontal and vertical magnetic centers of quadrupole magnets

Fig. 4. Schematic diagram of measuring method of horizontal magnetic center of sextupole magnet

Fig. 5. Ceramic double cone thread repeat positioning device

Fig. 6. Vibrating wire measurement program

Fig. 7. Vibrating wire data processing program

Fig. 8. Simplified schematic of magnetic center scan of vibrating wire

Fig. 9. Schematic diagram of vibrating wire sag

Table 1. Design parameters of the quadrupole and sextupole magnets

Table 1. Design parameters of the quadrupole and sextupole magnets

magnet	max. field	min. field	aperture /mm	magnetic length /mm	core length /m	turns per pole	max. of current /A	min. of current /A	good field region /mm	field errors	max. of power loss /kW	water pressure drop /(kg·cm⁻²)	water flow velocity /(m·s⁻¹)	temperature rise /℃	weight /kg
BS1QD13	33 T/m	1.5 T/m	40	300	290	13	411	19	±16	5×10⁻⁴	3	3	2.45	5.7	345
BS1SD6	1000 T/m²	30 T/m²	40	200	194	8	135.3	4.1	±16	1×10⁻³	0.33	3	1.89	3	75

Table 2. Ceramic double cone repeat positioning accuracy

Table 2. Ceramic double cone repeat positioning accuracy

vibrating wire repeated positioning method	cone angle	deviation X_max/μm	deviation Y_max/μm	deviation X_min/μm	deviation Y_min/μm	deviation X_sat/μm	deviation Y_sat/μm
compared with previous time	70°	8.3	4.4	0.1	0.2	2.7	1.3
	90°	4.9	1.1	0.0	0.0	0.9	0.3
	110°	5.9	4.9	0.0	0	1.4	1.4
compared with the initial zero	70°	18.9	3.0	0.0	1.1	6.4	0.6
	90°	5.5	2.4	0.0	0.0	1.0	0.6
	110°	6.0	6.4	0.0	0.1	1.6	1.9

Table 3. The vibrating wire is aligned on the horizontal magnetic axis of the pre-alignment unit

Table 3. The vibrating wire is aligned on the horizontal magnetic axis of the pre-alignment unit

position	operator	lattice value	horizontal offset/mm
fixed end magnetic axis point	1	−50.0	−1.000
fixed end magnetic axis point	2	−50.0	−1.000
fixed end vibrating wire	1	−50.2	−1.004
fixed end vibrating wire	2	−50.0	−1.000
free end magnetic axis point	1	−50.0	−1.000
free end magnetic axis point	2	−50.0	−1.000
free end vibrating wire	1	−50.2	−1.004
free end vibrating wire	2	−50.3	−1.006

Table 4. The vibrating wire is aligned on the vertical magnetic axis of the pre-alignment unit

Table 4. The vibrating wire is aligned on the vertical magnetic axis of the pre-alignment unit

position	visual distance of the instrument from each measuring point/mm	lattice value	lattice value deviation	vertical offset/mm	vertical offset deviation/mm	lattice value	lattice value deviation	vertical offset/mm	vertical offset deviation/mm
position		operator 1				operator 2
vibrating wire of the fixed end of the quadrupole magnet	2550	−41.0	50.0	−0.820	1.000	−41.5	51.0	−0.830	1.020
magnetic axis point of the fixed end of the quadrupole magnet	2295	9.0	50.0	0.180	1.000	9.5	51.0	0.190	1.020
vibrating wire of the free end of the sextupole magnet	2550	−43.0	50.0	−0.860	1.000	−43.0	50.5	−0.860	1.010
magnetic axis point of the free end of the sextupole magnet	2305	7.0	50.0	0.140	1.000	7.5	50.5	0.150	1.010

Table 5. Sag of vibration wire at the position of pre-alignment unit quadrupole and sextupole magnets
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Table 5. Sag of vibration wire at the position of pre-alignment unit quadrupole and sextupole magnets
type of magnet L/mm δh/mm f₁/Hz z₁/mm z₃/mm S(z)/mm
quadrupole magnet 7453.0 1.8 18.36 1272.0 1592.0 −0.218
sextupole magnet 18.30 1713.0 1931.0 −0.236

Table 6. Repeatability of vibrating-wire magnetic center scanning in pre-alignment unit

Table 6. Repeatability of vibrating-wire magnetic center scanning in pre-alignment unit

type of magnet	times	X/mm	X deviation/mm	Y/mm	Y deviation/mm	X/mm	X deviation/mm	Y/mm	Y deviation/mm
type of magnet	times	magnetic center of fixed end				magnetic center of free end
quadrupole magnet	the first time	−1.002	0.002	0.997	−0.002	−1.002	0.001	0.997	−0.003
quadrupole magnet	the second time	−1.000	0.002	0.995	−0.002	−1.001	0.001	0.994	−0.003
sextupole magnet	the first time	−0.959	−0.004	0.989	0.006	−0.965	−0.004	0.989	0.001
sextupole magnet	the second time	−0.963	−0.004	0.995	0.006	−0.969	−0.004	0.990	0.001

Table 7. Fit deviation of vibration line scanning of 3D magnetic center of the pre-alignment unit of the High Energy Photon Source booster