Progress of SRF and

ERL at Peking

UniversityLu Xiangyang

Institute of Heavy Ion Physics

Peking University

OUTLINE By the supports of both National Basic

Research Project (973) and Peking University, in recent years, the SRF Group, IHIP, PKU, are keeping the studies on SRF and ERL of:

• The study of cavity performance upgrade

• The upgrade of PKU DC-SC photo-injector

• The study of manufactory of TESLA 9-cell cavity

• The study of ERL-FEL

cavity upgrade

I. The study of cavity performance upgrade

Recent Nb SRF cavity is required to perform

*Higher acceleration field

*Higher Q and

*lower cost.

To reach those requirements, SRF people are focus on:

*The development of new cavity shape

*The application of new Nb material

*The development of new post processes

Based on the former studies on SRF and the evolvement of Chinese industrial Nb production, Peking University allied with OTIC, Ningxia do the effort together on the upgrade of cavity performance by the application of Chinese Nb material, especially on the application of large grain size and single crystal Nb sheets.

cavity upgrade

• Since 2005, PKU, OTIC and JLab started the co-operation of the cavity performance study which made of OTIC large grain size Nb sheets.

cavity upgrade

large grain size Nb sheets, OTIC

The single cell cavity made of OTIC LGNb, PKU

cavity upgrade

The 2-cell test cavity made of LGNb, PKU

cavity upgrade

Single cell Chinese Large Grain

Q0 vs. Eacc

1.00E+09

1.00E+10

1.00E+11

0 5 10 15 20 25 30 35 40

Eacc [MV/m]

Q0

Test#5a,after 1250C,3hrs,in situ bakedTest #2,no bakeTest#5,after 1250C,3 hrs, no bake

Test #2/5/5a

Quench @ 36.6 MV/m

cavity upgrade

Test results of 1.5GHz single cell cavity made of OTIC LGNb (by JLab).

The sample sheet The formed half cells

(after BCP,90m)

cavity upgrade

Since 2006, OTIC have got the success of produce the single crystal Nb sheet.

PKU is making a single cell test cavity use such material.

cavity upgrade

EBSD test of SCN before and after rolling

Elongation property study of single crystal Nb sheet

DC-SC injector

2002－ 2004， The idea of DC-SC had proved. The injector prototype is operated and tested. Under 4.5K, the beam energy gain is 1MeV, emmitance is 5 m,the highest current is 1 mA.

2004, DC-SC Photoinjector is collected by “RF SUPERCONDUCTIVTY-2004”, NSF, USA。

II.The upgrade of DC-SC photoinjector

Since 2005， the upgrade of DC-SC photoinjector was launched。 The major improvements are: The cavity from 1+1/2 to 3+1/2 cell, Eacc20MV/m. DC gun voltage up to 150kV. Redesign 2Kcryostat Expected properties： 5MeV, 1 5mA, 3 m.

DC-SC injector

China needs SRF accelerator.

PKU and OTIC launched the project of the development of SRF module

We start from very beginning:*The Nb sheets preparation and test*The art of deep drawing and EBW of TESLA type 9－ cell cavit

y*The post process of TESLA type 9－ cell*The RF measurement and tuning of TESLA type 9－ cell cavity*The technical of 2K cryostat

TESLA Cavity & Accelerator module

III. Development of home made TESLA type cavity and SRF accelerator module

The study of manufactory TESLA type 9-cell cavity

2k cryogenic system

Accelerator module

The designed parameters of the module

Frequency 1300 MHz

Operation temperature 1.8 ～ 2.0 K

Highest gradient >25 MV/m

Operation gradient 20~25 MV/m

Q0 @25 MV/m ~1010

Static heat loss < 8 W

Accelerator module

Draft design of PKU-ERL-FEL facility

PKU-ERL-FEL

IV. PKU-ERL-FEL

PKU-ERL-FEL parametersInject Energy 5 MeV

Maximum Energy 30 MeV

Bunch Frequency 26 MHz

Bunch Charge ~60 pC

Bunch length at Entrance of Undulator ~1 ps

Macro Pulse Length 2 ms

Rep. Frequency of Macro Pulse 10 Hz

Energy Spread (rms) 0.24%

Transverse Emittance （ rms, n.） ~3μm

Length of Undulator 1.5 m

λu of Undulator 3 cm

K of Undulator 0.5-1.4

Optical Cavity Length 11.52 m

Wavelength of FEL 4.7-8.3μm

PKU-ERL-FEL

PKU-ERL-FEL

PKU-ERL-FEL Facility concept

Thank you !

Welcome to SRF 2007, Peking University !