The Progress Report for KVN Construction

Seog-Tae Han and KVN staffs

Korea Astronomy and Space Science Institute

March18th 2009

Outline

- Overview of KVN- Antenna construction- Receivers and their test results- DAS(Data Acquisition System)- Future plan and Summary

Seoul (Yonsei)

Ulsan (Ulsan)

Jeju(Tamna)

2001 ~ 2008 3 stations with 21m radio telescopes - Cassegrain type 22,43,86 and 129GHz band Receiver - Simultaneous observation of four bands - first proposed in the world Digital DAS system has been completed Correlators will be completed in 2010 Millimeter-wave VLBI Astronomy

Overview of KVN

KVN Yonsei Observatory(Yonsei University at Seoul)

KVN Ulsan Observatory(Ulsan University)

KVN Tamna Observatory(Tamna University)

Efficiency(%)

EL(°)

Remark TB*(K)

Aperture efficiencies at 22GHz

Venus 68(70) 30 LPF2 505+-25**

Aperture efficiencies at 43GHz

Venus 68.8(70) 32 LPF2 450+-32

Aperture efficiencies at 100GHz

Venus 51 40

• Aperture efficiencies

• Pointing Accuracy - 4 arcsec at 100GHz

Outline

- Receivers and their test results

Quasi-optical circuit forMulti-band receivers

Quasi-optical circuit installed at receiver room of antennaQuasi-optical circuit installed at receiver room of antenna

M5

Calchopper

22GHz RX

43GHz RX

M4 M1

M2M3

43GHz( Black )

The Pointing offset between 22GHz and 43GHz band at Jupiter

)"7.0,"1.0(, ELAZ22GHz( Red )

Orion-KL H2O and SiO Maser Line

Simultaneous Observation Results !!!!!on October 28th 2008

East Asian VLBI Network with KVNEast Asian VLBI Network with KVN

YonseiUniv.

Mizusawa

W49N H2O maserStar formation region

W49N H2O MaserDater : 2008. 11. 1.

Honma et al.(2008)

Development of 22GHz receiver

RHCP LHCP

LNAs

Polarizer & OMT

Isolator

Development of 22GHz receiver

IF converter22GHz down to 9GHz/2GHz

Amplitude and phaseCalibrator for receiver

Development of 43GHz receiver

Isolator

RHCPLHCP LNAs

Polarizer & OMT

M&CLocal osc

KVN Down Converter Properties

Input Frequency : 8-10 GHz

Output Frequency : 512-1024 MHz

LO Frequency : 8.7-10.8 GHz, LSB

Number of Channel : 4 Channel

Output Power : ~ 0 dBm

Headroom : > 20 dB

Receiver Noise temperature of 22GHz and 43GHz band Receivers

F.S.+F.S Mode(22 GHz) & F.S.+F.M. Mode(43 GHz)Receiver Noise Temperature

0.010.020.030.040.050.060.070.080.090.0

9000 9500 10000 10500

FSyn [MHz]

Trx

[K

] 22G LCP22G RCP43G LCP43G RCP

Q-band HEMT amplifier from NRAO

Expected Receiver noise temperature : 35~40K

Outline

- DAS(Data Acquisition System)

DAS (Data Acquisition System)

4 channels Analog Inputs( 750MHz/500MHz IFs of 22, 43, 86, 129GHz ) 4 channels 2Gbps(500MHz) samplers 1Gbps recorder (MK5B) 256MHz, 128NHz,64MHz, 32MHz,16MHz and 8MHz 500MHz 4 channels digital spectrometers - single antenna observation mode It has been completed for 3 stations

Digital Spectrometer Mode 1. Wide band mode - 512MHz X 4 bands ( 22,43,86,129GHz) @4096ch. 2. Narrow band mode - 256MHz, 128MHz, 64MHz, 32MHz, 16MHz, 8MHz

Digital Filter mode

Outline

- Future plan and Summary

Timeline for system development2008 2009 2010 2011

Optics86/129G

22GHz

43GHz

86GHz

129GHz

Phase cal.System

Summary and Discussion

- Simultaneous observation for 22/43GHz and VLBI Observation between KVN and VERA successfully have been performed - Aperture efficiency : 51%@100GHz- Pointing accuarcy : 4”@ 100GHzx- 22/43GHz Receivers will be installed at KVN Ulsan and Tamna observatories in this year - 86GHz and 129GHz will be completed until 2011.

Thanks for your attention