# Presentation: 647717

## High Power Tests of Novel Fast Phase/Amplitude Modulators for HINS

***High Power Tests of Novel Fast Phase/Amplitude Modulators for HINS***
***(Fast Phase Shifters)******Robyn Madrak, APC***

## FNAL HINS

-  ***60 MeV Linac under construction at Fermilab’s meson building ***
*** ******Front end of 8 GeV Linac/Project X***
*** ******Fast Phase Shifters: allow ***_***all cavities***_*** (and RFQ) to be driven by a ***_***single klystron ***_***=> large cost savings***
*** ******(shifters provide independent phase and amplitude control for each cavity)***

## HINS 325 MHz RF

## How it Works

***How it Works***

**In a coaxial line filled with some material (ferrite) (******
**v = c/****√******

**We vary ******** (by changing B, by changing current in solenoid)**
**thus v and phase of reflected wave varies**

**outer conductor**

**inner conductor**

**B ~ I(solenoid)**

**inner conductor**
**shorted to outer conductor at end**
****** ****reflection**

**ferrite**

## Output Range: Single Phase Shifter

**Gyromagnetic resonance**
**(lossy region)**

**H = I(solenoid) * (#turns/cm)*4********/10**

## Fast Response Measurement

*** ******Useful phase shift range above resonance: ~50************s, 110****** ̊***
*** ******This gives an average slew rate of 2.2 ̊/************s ***
***(twice as fast as design spec)***

**solenoid**
**(#12 AWG wire)**

**slot**

**Ch 1:  Solenoid**
**Current (50A/div)**
**      **

**Ch 3: PhaseShift**
**(~17o /div)**

**gyromagnetic**
**resonance**

**useful phase shift range; low loss**

***Fast Response Measurement***

## Vector (I/Q) Modulator:

***Vector (I/Q) Modulator:***

***Modulates phase and amplitude independently:***
**	**
**With  ******** = (********2  *****- *********3****)/2**
**            ******** ****= (********2  *****+ *********3****)/2**
***Output power ~ *****cos****2****(*********)***
***Output phase ~ *******

**Input ****→**

**Output :****←**
**to circulator and cavity**

***Four Port ***
***Hybrid***

***water load***

***circulator***

## Two Sizes

***  ******~< 75 kW***
*** ******for each of the cavities***
*** ******Higher Power 31⁄8******′′***
*** ******550 kW***
*** ******for the RFQ only***
***(radiofrequency quadrupole)***

***Two Sizes***

## High Power Tests at Meson Lab

***High Power Tests at Meson Lab***

**325 MHz klystron**

**RF component**
**test cage**
**up to 2.5 MW**

**Cavity test cave**
**25 kW line,**
**250 kW line**

## Vector Modulators(for Cavities): High Power Tests

***Vector Modulators(for Cavities): High Power Tests***

*** ******phase ~ (*********1  *****+ *********2****)/2**

*here, solenoids on both phase shifters driven by one power supply*
**(********1 ****=***** *********2****)**

**→ *****Vector Modulators work well to > 75 kW***

## Vector Modulator Test with Cavity: 6kW

***Vector Modulator Test with Cavity: 6kW***

## Vector Modulator Test with Cavity: 6kW

***  ******Phase shifters (solenoids) driven independently by 2 supplies***
***  ******Output power ~ *****cos****2**** [(********1  *****-*********2****)/2]**
***   ******Relative levels (range)  = 13.6 dB***

- current, solenoid 2

- current, solenoid 1

- output power:
- cavity gap monitor

- current, solenoids
- 1 and 2

- phase detector:
- cavity gap monitor
- relative to input

***  ******Phase shifters (solenoids) driven in series by 1 supply***
***phase ~ (*********1  *****+ *********2****)/2**
***phase range ~ 155 degrees***

## RFQ Vector Modulator

-  ***31⁄8******′′ ******Phase Shifters good up to > 300 kW***
***  ******(req. ~250 kW each)***
*** ******31⁄8******′′ Hybrids: arcing at ~350 kW***
********* ******Will procure larger 6′′ hybrid***

## Conclusions/Summary

-  ***Lower Power 15⁄8******′′ Vector Modulators (for cavities)***
*** ******very encouraging results***
*** ******power/response speed all better than necessary***
*** ******these are ***_***all***_*** of the vector modulators except for 1 (for the RFQ)***
*** ******31⁄8******′′ (for RFQ)***
*** ******good results for shifters themselves***
*** ******Hybrid arced at high power: need a larger one***