G5 Design Review, April 24, 2009 Gun to 5cell Cavity Test: Overview Dmitry Kayran G5 test Design Review April, 24 2009

G5 Design Review, April 24, 2009G5 Design Review, April 24, 2009

Gun to 5cell Cavity Test: Overview

Dmitry Kayran

G5 test Design ReviewApril, 24 2009


OutlineOutline• Goals of G5 Test• G5 layout and main components• Parameters and regimes• Plans & Conclusions


Why we are doing the G5 test?

• G5 test is first stage of ERL commissioning– Most of all ERL components can be tested during G5Test

• Will demonstrate of high brightness SRF Injector operating

• The high energy at the end• We will measure:

» Projected emittance in both planes» Bunch length and longitudinal tails» Slice emittance» Energy spread

• To have a base line for comparison of straight line and z-bend merger system performance


ERL setup


G5 setup


G5 test layout

SRF 5cell cavity

SRF Gun Triplet

Beam Profile Monitors OTR/Yag Screens

Dipole

Solenoids

Transport car

Faraday Cup

GUN S

FC

T

Halo m

onito

r

S 5 cell RF

- BPMs

FC

ERL quad triplet

quadinterchangeablescreen/slit

0.3 m14º

- OTR/YaG screens

Pep

per-pot

S

- Steering dipoles

1.95 m


G5Test: Components

• SRF Gun and 5cell cavity, Cryosystem for both• 1MW Klystron and 50kW RF power supplies, LLRF• Vacuum chambers, pumps, control• Cathode, Deposition System, Transport Car, Laser,

Laser Control• Magnets and Power Supplies: HTS solenoid, solenoids,

steering dipoles, quadrupoles, 14° dipole (ERL 60° dipole will be used)

• Instrumentation: beam profile monitors, beam position monitors, beam current monitor


Main parameters for G5 test

• Charge per Bunch: 0.05-5 nC• Gun Energy: 2.5 -3 MeV• Maximum Energy: 20 MeV• Max. Average current: 500 nA• Max. Rep Rate: 100 Hz• Average Power: < 10 Watts• Trains mode operation


Electron beam parameters and regimes for G5test

Start-up Base line High charge

Cathode Cooper Multi-Alkaline Multi-Alkaline

Long. Pulse shape (FWHM)

12 psec Sin(x)/x 50 psec flattop 70 psec flat top

Trans. Pulse shape Gaussian 2.5 mm sharp edge 3 mm sharp

RF frequency 703.55 MHz 703.55 MHz 703.55 MHz

Operational regem Pulses of trains Pulses of trains Pulses of trains

Rep. rate in train 9.383 MHz 9.383 MHz 9.383 MHz

Train length 100 pulses 100 pulses 100 pulses

Trains rep. rate 0-1 Hz 0-1 Hz 0-1 Hz

Charge per bunch upto 50 pC 1.4 nC 5 nC

Gun kinetic energy 2.0 MeV 2.0 MeV 2.5 MeV

Max. Energy 20 MeV 20 MeV 20 MeV

Max average current 0.001 mA 0.001 mA 0.001 mA

Max average power 20 W 20 W 20 W


Beam Parameters to Measure

At 20MeV two operational modes: 1. Straight ahead

– projected emittance– transverse halo

2. With the bend– bunch length / long. halo /energy

spread– slice emittance

Plan to do at low energy- Cathode QE and

- Cathode lifetime in SRF gun

- Slice emittance

- Projected emittance

- Halo studies

GUN S

FC

T

Halo m

onito

r

S 5 cell RF

- BPMs

FC

ERL quad triplet

quadinterchangeablescreen/slit

0.3 m14º

- OTR/YaG screens

Pep

per-pot

S

- Steering dipoles

1.95 m


Straight ahead path: Quad scanOnly one quad of the triplet is used for quad scan. Assuming that PS’s are unipolar, the first quad can be used for the horizontal quad scan, while the second quad can be sued for the vertical scan.

x,min 200 mymax(95%) 6 mmx (Parmela) 1.43 mx (“reconstructed”) 1.45 m

1st quad y,min 135 mxmax (95%) 6 mmy (Parmela) 1.43 my (“reconstructed”) 1.46 m

2nd quad

We will be able to measure emittances in 1 m range


G5 test Status• During the 5cell cavity Cold Emission Test:

– 5cell cavity (Cryo, Vacuum, Controls, RF PS, LLRF) tested ( 20 MV/m achieved in pulsed mode). – PASS, MPS and general control systems tested– BLMs, pin diodes, PMT, chipmunks tested– Next CET Feed back system needs to be tested.

• SRF Gun is under-construction in AES. • 1MW RF power supply has been tasted. Waveguide components to SRF Gun needs

to be designed• Laser is here and will be tested soon. Laser beam delivery system is under

constraction.• Cathode deposition system and transport car are in 966 • Dipole and quads are tested and available• All solenoids (HTS and normal) assembled, magnetic measurements needs to be

done.• Some ERL vacuum components will be reused other were designed• Steering dipoles need to be design • Main magnets power supply are here, lower current PS needs to be purchased• Beam profile monitors (Radiobeam) will be reviewed next month• Pepper pot system and Faraday cup (preliminary discussed with Princeton scientific) • Halo monitor (there are two crosses -place holders for halo monitors) needs to be

designed


Commisionnig plan: ERL fully operational in 2011

We start commissioning of the R&D ERL components 5cell SRF cavity cold emission test

•first cool-down March, 14, 2009

•20 MV/m in CET April, 23 2009G5 test (low average current) work in progress•First, the straight pass (gun -- 5 cell cavity -- beam stop) test for the SRF Gun performance studies. (October 2010)

#Metal cathode (low charge per bunch)

#Multi-Alkaline Cathode (up to 5nC per bunch)•Next, a novel concept of emittance preservation in a beam merger at the lower energy will be tested (end of 2010)

•After recirculation loop completed, demonstrate energy recovery of high charge and high current beam.The prototype will serve as a test bed for studying issues relevant for very high current ERLs (2011)

•Proof of principle coherent electron cooling ions in RHIC at ~ 40 GeV/n is feasible with existing R&D ERL parameters (ERL available around 2012)


2-3 MeV

2-3 MeV

20 MeV

20 MeV

20 MeV

2-3 MeV

SC RF GunSC 5 Cell cavity

Beam dump

BPM

DCCT

1MW Klystron

SRF Linac50 kW Transmitter operational

Arc assembly

Quadrupole

Dipole

Tested in

BLD912

ready for

gun

First cool-down, March, 2009 T=2K

Measured, ready to be

installed

BNL R&D ERL: Status


Thank you


• Backup slides


Transport car

• Under two ion pumps operation, the baseline vacuum is 2*10-8torr without baking.

• Baking the transport car. The temperature is kept at 200C except the bellow which is kept at 150C for 50 hours.

• The baseline vacuum is 3*10-8torr after baking.( We don’t know why until now)

• Leak test. No leak on the transport car.


BNL R&D ERL Status: complete Design of major ERL components is completed. Hardware components are being

manufactured and/or procured.

– ERL Enclosure (Vault) was constructed (2005)

– 5-cell Cavity is being processed and tested at JLAB, installed at 912. First cool down T=2K in March 2009. Cold Emission Test next week.

– The preparation chamber for SRF gun photo-cathodes under vacuum studies

– 1 MW Gun klystron (for SRF gun) including circulators and dummy loads installed, tested for full power 1MW

– 50 kW (for 5 cell 20 MeV SRF linac) installed, tested

– Recirculation loop magnets and injection line magnets have arrived and measured. Magnets power supplies were delivered.

– Loop vacuum system components are on hand

– RF control will be based on the new digital RHIC LLRF. The LLRF system is currently under development. (CET will use PLL based LLRF and move to digital LLRF then one is available).

– Machine protection system is installed


BNL R&D ERL Status: to do list..

• Laser room completion (April, 2009)• Gun drive laser is been procured (arriving in May, 2009)• G5 test additional components designed some needs to

be ordered yet (June 2009)• Extraction line component, magnets, vacuum chamber

under design• Gun is under construction at AES (Cold Emission Test at

BNL October 2010)


5-Cell cavity, full load

• Start: 650 L, 80 kg (density=123.9 g/L)• End: 304 L, 44.3 kg (density=145.6 g/L)• Unusable volume: 100 L• Usable Volume: 204 L at 145.6 g/L = 29700 gr.• Usable heat capacity:

29700 x 23.4 J/g =695 000 Joules• Usable time: 695 700 J / 50 W / 3600 s/hr = 3.8

hours


Gun

• Start: 167 L, 20.7 kg (density=123.9 g/L)• End: 78.1 L, 11.4 kg (density=145.6 g/L)• Unusable volume: 20 L (17L)• Usable Volume: 58.1 L at 145.6 g/L = 8460 gr.• Usable heat capacity: 8400 x 23.4 J/g = 197 964

Joules• Usable time: 197964 / 14 W 3600 s/hr = 3.9

hours

Documents

G5 Design Review, April 24, 2009 Gun to 5cell Cavity Test: Overview Dmitry Kayran G5 test Design Review April, 24 2009