Gatling Gun Program Review, June 28th-29th, 2012

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Gatling Gun Program Review

Charge to the Review CommitteePresented by

Ilan Ben-ZviAccelerator R&D Division Head

Collider-Accelerator DepartmentBrookhaven National Laboratory

RHIC

NSRLLINACBooster

AGS

Tandems

STAR6:00 o’clock

PHENIX8:00 o’clock

10:00 o’clockPolarized Jet Target

12:00 o’clock

RF4:00 o’clock

(AnDY)2:00 o’clock

RHIC – a High Luminosity (Polarized) Hadron Collider

Operated modes (beam energies):Au – Au 3.8/4.6/5.8/10/14/32/65/100 GeV/nd – Au* 100 GeV/n Cu – Cu 11/31/100 GeV/np – p 11/31/100/205/250 GeV Planned or possible future modes:Au – Au 2.5 GeV/n (~ SPS cm energy)U – U 100 GeV/np – Au* 100 GeV/nCu – Au* 100 GeV/n (*asymmetric rigidity)

Achieved peak luminosities:Au–Au (100 GeV/n) 1951030 cm-2 s -1

p–p (250 GeV) 1501030 cm-2 s -1

Other large hadron colliders (scaled to 250 GeV):Tevatron (p – pbar) 1081030 cm-2 s -1

LHC (p – p) 2601030 cm-2 s -1

EBIS

The Accelerator R&D Division

• The C-AD Accelerator R&D Division is engaged in R&D towards eRHIC, a proposed electron – hadron collider based on RHIC.

• The major R&D projects of the division:– The design of eRHIC, – The R&D ERL, – The Coherent electron Cooling POP experiment,– The 50 mA polarized electron source for eRHIC.

The Funneling Gun

• The high current polarized electron source is based on funneling 20 independent cathodes.

• We are funded by strategic LDRD to prove the feasibility of funneling as applied to a polarized electron gun.

• We are also interested in building up local expertise in the subject.

The charge to the committee

• The Cathodes – Consider cathode preparation– Consider adequacy of the cathode cooling system.

• The electrostatic design of the gun.– Is the gun design is electrostatically conservative. – Consider potential charging of the alumina ceramic inside

the combiner magnet.

• The quality of the vacuum system design, in particular:– The general design of the chambers for XHV.– The element of risk by the fabrication of the gun using

multiple commercial vendors, imposed by the restrictions on in-house staff.

– Potential failure points due to in-vacuum motion elements.– Consider the design for obtaining, maintaining and reading

XHV reliably.

• Laser and optical design – The issues of setup and alignment of twenty separate

lasers onto twenty separate photocathodes.– Consider the optical windows, such as issues of

birefringence.– Consider halo generation from stray light.– Consider the issues associated with delivering beam pulses

with identical bunch charge from 20 cathodes.

• Other issues.– Consider potential issues with the “C” magnets used

to deflect the beam, such as astigmatic focusing.– Consider the phased plan of the experiment and the

proposed schedule.– Beam instrumentation– Beam dump

• Each talk will provide information on open issues and potential trouble spots

Gatling Gun Program Review, June 28th-29th, 2012

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Review Agenda

Start Time Topics Speakers 9:30 Introduction to the Gatling Gun Development Program J.Skaritka 10:00 Experience with GaAs Cathodes at BNL T. Rao

10:20 Polarized GaAs Cathode development and preparation of Gatling Gun Cathodes E. Riehn

10:40 Break

11:00 Electro-Static Modeling Q. Wu

11:30 Beam Physics Modeling and Combiner design E. Wang 12:00 Lunch (served in this room) 1:00 Tour of Cathode Preparation Lab Bldg. 966 E. Riehn 1:30 Vacuum system development and status J. Skaritka 2:10 Laser System development and status B. Sheehy

2:30 Break 2:50 Beam Diagnostics and Instrumentation D. Gassner 3:10 Depressed Collector and High Voltage system S. Pikin 3:30 Outside component manufactures and status J. Skaritka

Welcome and thanks

• Welcome to the committee members – we appreciate your help!

• Thanks for the team working on the Gatling Gun!