J.H. Lee BNL Correlations Fest, June 2002, BNL HBT in BRAHMS.
E/B PEDM R&D - BNL
Transcript of E/B PEDM R&D - BNL
![Page 1: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/1.jpg)
E/B PEDM R&D
W. Morse PEDM Review 1
W. Morse 12/7/2009
![Page 2: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/2.jpg)
Large Scale Electrodes
Parameter Tevatron pbar-p Separators
BNL K-pi Separators
PEDM
Length 2.6m 4.5m 2.4m
Gap 5cm 10cm 2cm
W. Morse PEDM Review 2
Gap 5cm 10cm 2cm
Height 0.2m 0.4m 0.2m
Number 24 2 64
Max. HV ±180KV ±200KV ±190KV
![Page 3: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/3.jpg)
Tevatron pbar-p Separator Module
W. Morse PEDM Review 3
![Page 4: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/4.jpg)
HV Feedthrough to 0.2m High Electrodes
W. Morse PEDM Review 4
![Page 5: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/5.jpg)
101in. Long Separator Electrode
W. Morse PEDM Review 5
![Page 6: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/6.jpg)
Construction of 101 in. Long Separator Electrode
W. Morse PEDM Review 6
![Page 7: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/7.jpg)
FN Field Emission Current vs. E
Fowler-Nordheim Equ.
0.1
1
W. Morse PEDM Review 7
0.001
0.01
0.1
0 10 20 30 40
E (GV/m)
I (p
A/c
m^2
)
![Page 8: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/8.jpg)
Recent Progress from LC/ERL R&D (5mm gap tests) Cornell/JLab
W. Morse PEDM Review 8
![Page 9: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/9.jpg)
V vs. Gap: Fengnian & Weihan, IEEE Tran. Electrical Insulation 25, 557 (1990)
W. Morse PEDM Review 9
![Page 10: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/10.jpg)
How to Scale from 5mm Gap to 2cm?
15
20
25
30
EFE
Field Emission Heating or Macro-Particle Heating for New Methods?
W. Morse PEDM Review 10
0
5
10
15
5 10 15 20
Gap (mm)
EFE
MP
![Page 11: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/11.jpg)
Sparks
• Oleg Prokofiev, the Tevatron pbar-p separator team leader:
• Current conditioning – HVPS in current limiting mode,• Gas conditioning – 10-4 Torr glow discharge region,• Spark conditioning – start out at many sparks/hr, 1
W. Morse PEDM Review 11
• Spark conditioning – start out at many sparks/hr, 1 spark/day after several days, run for one week.
• “To reach ±150-170KV for PEDM electrodes and have ~1spark/month, conditioning will be performed at ±165-190KV”.
• Tevatron pbar-p separator goal was 1spark/yr per module – pbars are precious.
![Page 12: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/12.jpg)
Beam Impedance
• J. Crisp and B. Fellenz, FNAL-TM-2202 and K. Ng, Proc. 2003 Part. Acc. Conf. IEEE7803-7739-9.
• “The conclusion points to the fact that the separators actually contribute negligibly when compared with other discontinuities in the Tevatron vacuum chamber, except for the rather large resonance at 22.5MHz”.
W. Morse PEDM Review 12
for the rather large resonance at 22.5MHz”. • The Tevatron runs with 0.1A average proton current,
while PEDM has only 3mA.• Tevatron separator measured Re (ZL0/n) and Re (ZT1)
impedances were 0.08Ω, 0.01Ω, 0.2MΩ/m, and 0.04MΩ/m at the peak of the 22.5 and 67.8 MHz resonances, respectively. Need C-AD help to avoid resonances.
![Page 13: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/13.jpg)
Longitudinal Beam Impedance
• Systematic error for spin.• Beam power loss = I2 Re (ZL0).• RF makes up beam power loss.• If RF cavity is inclined, CW and CCW beams
W. Morse PEDM Review 13
• If RF cavity is inclined, CW and CCW beams see different Ev, which is a systematic error for magnetic focusing, as Yannis described.
• Require ring Re (ZL0) < 10KΩ. Need C-AD help to avoid resonances.
• This is not a systematic for electric focusing.
![Page 14: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/14.jpg)
Vertical Electric Field Systematic
• If CW/CCW beams see different Ev, this is a systematic for magnetic focusing (<5nV/m).
• Image charges, etc.• Solution: keep plates high
enough.
W. Morse PEDM Review 14
![Page 15: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/15.jpg)
Image Charge vs. y for Infinite Plates
1.E-03
1.E-02
1.E-01
1.E+00
W. Morse PEDM Review 15
1.E-07
1.E-06
1.E-05
1.E-04
1.E-03
0 2 4 6 8 10
![Page 16: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/16.jpg)
Quadrupole Magnet Design – W. Meng Collider-Accelerator Dept.
W. Morse PEDM Review 16
![Page 17: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/17.jpg)
E vs. Gap Test from June 2009 C-AD Review
W. Morse PEDM Review 17
![Page 18: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/18.jpg)
E vs. Gap Test Level of Effort
Construction – Tech. 200mh $20K
Construction – Eng. 100mh $10K
Material $24K $24K
W. Morse PEDM Review 18
Material $24K $24K
Testing - Physicist $120K $120K
Testing – Tech. $35K $35K
Total $209K
![Page 19: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/19.jpg)
First E Module
W. Morse PEDM Review 19
![Page 20: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/20.jpg)
Start date set arbitrarily to Jan. Natural time to start is June 2010.
W. Morse PEDM Review 20
![Page 21: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/21.jpg)
First E Module Level of EffortItem K$
Electrode Plate 27.5
Vacuum Tank 35.7
End Flange 13.5
Ports 35.5
Vacuum Tank Assembly 6.3
W. Morse PEDM Review 21
Vacuum Tank Assembly 6.3
Electrode Assembly 3.8
Inner Support Structure 48.1
Gauges 22.5
Vacuum Equipment 104.1
Vacuum Hookup 5.0
Instrumentation and Commissioning 52.5
Total 356.4
![Page 22: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/22.jpg)
Milestones
• May, 2010 – Commission E vs. gap test setup.
• June, 2010 – Start first E module design.• October, 2010 – E vs. gap results.
W. Morse PEDM Review 22
• October, 2010 – E vs. gap results.• February, 2012 – Commission first E
module test.• May, 2012 – Finish first E module test.
![Page 23: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/23.jpg)
Conclusions
• $0.6M E/B R&D over 3 years• Relatively low technical/cost risk• X% lower E field strength:
W. Morse PEDM Review 23
• increases the ring length by X%• and decreases edm sensitivity by X%.
![Page 24: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/24.jpg)
Extra Slides
W. Morse PEDM Review 24
![Page 25: E/B PEDM R&D - BNL](https://reader033.fdocuments.in/reader033/viewer/2022042609/62634eaf88b8c17428213dc6/html5/thumbnails/25.jpg)
RF Inclined
• Beam is blue.• Electric field is red.
W. Morse PEDM Review 25