aac’08 santa cruz ca, july 27th - august 2nd 2008 development of a ferroelectric based tunable dla...

AAC’08 Santa Cruz CA, July 27th - August 2nd

2008

DEVELOPMENT OF A FERROELECTRIC BASED TUNABLE DLA STRUCTURE*

A.Kanareykin Euclid TechLabs LLC, Rockville, MD

*This work is supported by

the DOE, High Energy Physics

AAC’08, Santa Cruz CA, 2008


2008

A.Kanareykin, Euclid TechLabs LLC C.Jing, Euclid Techlabs LLC/ANL

E. Nenasheva, Ceramics Ltd A.Semenov, Eltech University

P.Schoessow, Euclid Techlabs LLCJ.G.Power, Argonne National Lab

W.Gai, Argonne National Lab

PROJECT IN COLLABORATION WITH ANL/AWA

TEAM


2008

Tunable Dielectric Loaded Accelerator

d

Ferroelectric

MW dielectric

Electrodes to apply dc field


2008

Development of a 400 μm Thin Cylindrical BST(M) Ferroelectric

Layer.

Press-form for the waveguide fabrication that makes possible to place tubes inside horizontally providing uniformity of compaction along its length.

Raw form of the cylindrical ceramic waveguides made of forsterite ceramic, permittivity of 6.8 (white) and BST-MgO-Mg2TiO4, BST(M) ferroelectric (grey).


2008

the set of the “witness” samples for 3 - 9 GHz and 1 MHz dielectric response measurements

Dual Layer Forsterite – BST(M) Structure

forsterite BST(M)


2008

BST(m) Mechanical Properties

Double layer dielectric-based accelerator loading assembly Thermal Conductivity

7.02 W/m-K

Coefficient of Thermal Expansion

10.1*10-6 K-1

Modulus of Elasticity 1.7*102 GPa

Poisson’s Ratio0.2

Density4.86 g/cm3

Specific Heat0.605 kJ/kg-K

Bending Strength127 MPa


2008

The Tunable DLA Resonator with Double Layer Loading

K-band TM01 launcher and the setup for the K band dielectric accelerating structure bench testing at the ANL/AWA


2008

SuperLANS simulations of the (a) TM011, 18821.3GHz; (b) TM012, 19195.8GHz and (c) TM013, 19760.4GHz modes of the DLA resonator.

SuperLANS simulations*

Δf/f=1/2(Qf/Q)(Δε/ε)#

*I.Gonin, V.Yakovlev#

ε TM011 MHz/ Q1 TM012 MHz/ Q2 TM013 MHz/ Q3

55018821.3

99019195.8

90119760.4

756

53918859.2

101219237.4

92019809.5

800

52018924.6

104919308.8

98019892.4

860

49519011.0

109019402.3

102019999.6

925


2008

TM011 mode

TM012&TM013 mode

C. Jing, April 2008.

Temperature Tuning of the DLA Structure

Temperature tuning of 14 MHz/0K


2008

28,0 28,5 29,0 29,5 30,0 30,5 31,0 31,5 32,0-4

-3

-2

-1

0

18 oC

27 oC

30 oC

32 oC

34 oC

39 oC

S11

, dB

f, GHz

29.6

29.7

29.8

29.9

30

30.1

30.2

30.3

18 27 30 32 34 39

GHz

T,0C

A.Semenov, April 2008

Temperature Tuning of the Ka-band Planar DLA

Resonator

Temperature tuning of 18 MHz/0K


2008

High Voltage Tuning Setup

layout of the double layer DLA resonator with the high voltage supply set and coaxial TM mode launcher for the bench testing


2008

C.Jing, April 2008.

frequency spectrum shift of the Ka band tunable ferroelectric based DLA

High Voltage Tuning Demonstration

6 MHz at 20 kV/cm


2008

Edc Emw

(B)

Emw Edc

transparent electrode

(A)

28,5 29,0 29,5 30,0 30,5 31,0 31,5

-5

-4

-3

-2

-1

S1

1, d

B

f, GHz

f=85 MHzE=2 V/m

High Voltage Tuning of the Ka-band Planar DLA

Resonator

A.Semenov, April 2008

S11 measurements of the tunable Ka band resonator85 MHz frequency shift at 20 kV/cm dc voltage


2008

Ceramic stand offs

4”

Finger stock

SHV-20KV CONNECTOR

1 2

1 2 3 4

4 x 3.38” CF

C.Jing, R.Konecny

a, cm b, cm c, cm 1 2

0.300 0.598 0.638 4.7 250

Beam Test of the Tunable DLA

SHV 20 kV connector and “transparent” dc contacts

TM01 - 9.99 GHz TM02 - 15.60 GHz TM03 - 33.13 GHz


2008C.Jing, April 2008.

Tunable Wakefield Power

Extractor.

The difference from the conventional dielectric-based wakefield power extractor is that we use two ferroelectric slabs that position along the outer surface of the dielectric tube. The rest area of the dielectric tube is covered by a split copper tube to hold the metallic boundary condition.


2008

Summary

Temperature variation: - 14 MHz/K0 for the cylindrical Ka-band leading to an overall structure frequency tuning range of (140 - 280) MHz in 10-200K (slow tuning !!!)

HV Tuning of the Cylindrical DLA: ~ 6 - 8 MHz at 20 kV/cm (transverse bias). Fast tuning (!!!) from 10s ns to 100s μs ranges.

HV Tuning: 85 MHz for the 30-34 GHz prototype planar DLA structure at 20 kV/cm (parallel bias), 20 MHz at 20 kV/cm (transverse bias).

The best solution: a combination of ”coarse” but slow temperature tuning by 100s of MHz and rapid fine tuning with high voltage dc biasing applied.

aac’08 santa cruz ca, july 27th - august 2nd 2008 development of a ferroelectric based tunable dla...

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