IP-BPM status Siwon Jang KNU

Contents The electronics repair status –Repair work status –Electronics RF test (by using Oscilloscope) –Electronics shipment to KEK May beam test plan –Basic system check –Beam test scheme –Test list

The repair status for KNU electronics 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 Hybrid Mixer LO RF BPF Whole the mixer parts were replaced to new mixers at this week Monday.

The linear range test of KNU electronics after repair works RF test scheme S/G for LO KNU electronics Oscilloscope S/G for RF RFLO 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: GHz RF Frequency: 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 repair The entire KNU electronics was repaired and the conversion gain was set to 54dB with almost 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 spectrum 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 intensity. –The beam test for 54dB calibration factors for x and y port with dynamic ra nge check –The data taking and analysis program modify to use new ADC system 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 b eam position resolution study. The resolution study of IP-BPM with 54dB ele ctronics. etc...

Ref. cavity output power check due to different beam intensity Cable connection Inside tunnelOutside tunnel Ref. cavity beam IPBPM Y-port V.Att to elec. Ref. Y-port Splitter to elec. Splitter to diode Half inch cables Charged ADC 14bit IPA IPB IPC Variable remote att. KNU electronics 45dB Spectrum analyzer 10dB Att. IP Ref. signal splitter The Ref. cavity BPM Output power will be checked by using Spectrum analyzer. (Max hold function Can measure pulsed signals during long pick 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 BPM 5 ~ 22dB -6dB spliter loss From BPM -11 ~ 6dB IP-BPM set-up scheme until now 10dB Att.

The BPM fabrication plan AprilMayJuneJulyAug.Sep.Oct. Ref. BPMorder Fabrication RF Test Install Sensor BPMDesign studyFabrication Test & Install Feed throughorderfabrication Delivery The Mr. Sandry will visit to KNU to discuss about new fabrication of IP-BPMs during 27~29 th May.