IP-BPM status

Siwon JangKNU

Contents

• The electronics repair status– Repair work status– Electronics RF test (by using Oscillo-

scope)– Electronics shipment to KEK

• May beam test plan– Basic system check– Beam test scheme – Test list

The repair status for KNU elec-tronics

• Whole the electronics was repaired at this week Monday.– 12 mixer parts were replaced to new mixers.– The resister part was replaced to original values.– The total conversion gain of electronics was set to 54dB.– The IF offset voltage was set to 0mV (±700uV).– The electronics will be sent to KEK at tomorrow by EMS.

• After the repair work, the electronics was tested to check it’s performance.– The 54dB gain was checked!– The IF signal output voltage offset was set to 0mV (±700uV).– The linear range was checked but lower limit could not checked.– LO input working range was checked!

The repair work for whole mixers

LNA

Ring coupler

19dB DA

19dB DA

Hybrid

Mixer

Mixer

LO

RF

RF

BPF

Whole the mixer parts were replaced to new mixersat this week Monday.

The linear range test of KNU electronics after repair works

• RF test scheme

S/G for LO

KNUelectron-

ics

Oscillo-scope

S/G for RF

RFLO

IF

IF

The IF signals were checked by using oscilloscope. The signal waveform was checked and the IF output power was checked by using FFT of oscilloscope.

Y-port electronics check

• LO Frequency: 6.404 GHz• RF Frequency: 6.409 GHz

• The Input RF power: -60dBm• The Output IF power: -6dBm

– Total conversion gain = 54dB (for 5Mhz difference)

• The voltage offset setting– Within ±700uV

Y-port electronics check

• RF working range check!

Y-port electronics check

• LO working range check!The LO input signals working range: -5dBm to

25dBm

Conclusion of electronics re-pair

• The entire KNU electronics was repaired and the conversion gain was set to 54dB with al-most 0mV voltage offset (Within ±700uV)

• The RF input power working range was -45dBm to ~-100dBm. However, we could not checked lower detection limit of electronics. For this, we will check again by using spec-trum analyzer at KEK.

• The LO input power working range was from -5dBm to 25dBm.

May beam test plan• We first will check the electronics performance (1 ~ 2 beam shift need)

– The signal waveform will be checked and compare with previous beam test results.

– The phase shifter performance will be checked.

– Ref. cavity BPM output power check due to different beam inten-sity.

– The beam test for 54dB calibration factors for x and y port with dynamic range check

– The data taking and analysis program modify to use new ADC sys-tem from FONT group.

Further beam test plan

• The X-Y isolation check with beam jitter at 10 x 1 optics (suggest by Oscar and Tauchi san)

• The re-check for misalignment between IP-BPM A, B and C– Tilt misalignment is most important issue for higher

beam position resolution study.

• The resolution study of IP-BPM with 54dB electronics.

• etc...

Ref. cavity output power check due to different beam intensity

• Cable connection

Inside tunnelOutside tunnel

Ref.cavity

bea

m

IPBPM Y-portV.Att to elec.Ref. Y-portSplitter to elec.Splitter to diodeHalf inch ca-bles

Charged

ADC14bit

IPA

IPB

IPC

Variableremote

att.

KNUelectronics

45dB

Spec-trum ana-lyzer

10dB

Att.

IP

Ref.signalsplit-ter

The Ref. cavity BPMOutput power will bechecked by usingSpectrum analyzer.(Max hold functionCan measure pulsedsignals during longpick up time.)

Reference cavity output power check beam test

• The LO working range of electronics was -5dBm to 25dBm.• The input LO power in front of electronics should be larger than -5dBm. • However, the current beam test scheme can make out of working range for

LO input signal so that we should check actual Ref. BPM output power level. - Cavity size :

42.95mm,38.65mm- Beam Pipe radius: 8 mm (circular pipe)- Material of BPM: Stainless steel (SUS304)

Output signal strength= 5 ~ 22dB (0.2 ~ 1 x

1.6nC)

From BPM5 ~ 22dB

-6dB spliter loss

From BPM-11 ~ 6dB

IP-BPM set-up scheme until now

10dB

Att.

The BPM fabrication plan

April May June July Aug. Sep. Oct.

Ref. BPM order Fabrica-tion

RF Test

In-stall

Sensor BPM Design study Fabrication

Test &In-

stall

Feed through or-der fabrication

Deliv-ery

The Mr. Sandry will visit to KNU to discuss about new fab-rication of IP-BPMs during 27~29th May.