# Presentation: 114761

## Tevatron Schottky Progress & LARP Schottky Task Status

- Andreas Jansson
- Fermilab

- LARP Collaboration Meeting,  October 5-6, 2005

## Tev Tune Stabilization

- 1.7 GHz Schottky tunes now used to stabilize pbar tunes during stores!!!
- Proton tunes are next...

**16 week tune history**

- LARP Collaboration Meeting,  October 5-6, 2005

## Tev Accuracy Improvements

- Implemented on-line averaging and other software enhancements.

**16 week averaged tune history**

- LARP Collaboration Meeting,  October 5-6, 2005

## Tev BB Tune Spread

- Schottky and SBD momentum spread agree very well for protons...

- Schottky measures momentum spread based on the assumption

**Schottky dp/p**

**SBD dp/p**

**Schottky dp/p**

**SBD dp/p**

- LARP Collaboration Meeting,  October 5-6, 2005

## Tev BB tune spread II

**For pbars, there is a distinct offset early in the store!!!**
- Used to attribute this to low S/N, since noise floor is higher, but that implies
- that the Schottky ‘emittance’ should be low in the beginning of  a store, which
- is no longer true!

**Schottky dp/p**

**SBD dp/p**

**Schottky baseline**

**Schottky emittance**

- LARP Collaboration Meeting,  October 5-6, 2005

## Tev BB tune spread III

- Hence (assuming it is real) it must be a tune spread contribution
- NOT coming from momentum spread

- LARP Collaboration Meeting,  October 5-6, 2005

## Tev BB tune spread IV

- Tune spread scales as Xi parameter → beam-beam

- LARP Collaboration Meeting,  October 5-6, 2005

## Tev BB tune spread V

- 0.005

-  ...and the change in tune shift during the store is
- approximately twice the observed tune spread
- change, as expected.

- LARP Collaboration Meeting,  October 5-6, 2005

## LARP Schottky Task

- Status Quo – while waiting for funding
- $245 requested in LARP FY06 budget
- FNAL: $180k SWF, $45k MSTC
- BNL:     $20k SWF
- Ralph will visit CERN in November to hash out all relevant details
- Andreas not able to go due to US visa bureaucracy (I’ll tell you the whole story in the bar tonight).

- LARP Collaboration Meeting,  October 5-6, 2005

## Budget estimate

|  | FTE years | M&S |
| --- | --- | --- |
| Design PU structure | 5/12  |  |
| Design & build electronics | 3/12 | $25k |
| DAQ study (BNL+FNAL) | 2/12  |  |
| Port software 
 | 3/12  |  |
| Installation and commissioning | 2/12 | travel* |

- *Two short trips to CERN, plus one longer trip for commissioning
-   for two people each time

**From Port Jeff collaboration meeting**

- LARP Collaboration Meeting,  October 5-6, 2005

## Tentative milestones

| FY06 | FNAL | S/N study of low intensity bunches in Tevatron |
| --- | --- | --- |
| FY06 | FNAL | Design pick-up structure |
| FY06 | BNL/FNAL | Study PLL DAB board for DAQ  |
| FY06-07 | FNAL | Design and build front-end electronics |
| FY06-07 | FNAL | Adapt Fermilab analysis software |
| FY07-08 | FNAL | Hardware commissioning at CERN 
(w and w/o beam) |
| FY07-08 | FNAL | Beam studies (e.g. chromaticity, ramp) |
| FY07-08 | LARP | Non-destructive average tune, emittance, momentum spread and chromaticity measurement capability |
| FY07-08 | LARP | Non-destructive bunch-by-bunch tune, emittance, momentum spread and chromaticity measurement capability |

**Ultimate goals in black**

**From Port Jeff collaboration meeting**

- LARP Collaboration Meeting,  October 5-6, 2005

## Details (to be worked out)...

- A study of performance limitations in terms of S/N for low intensity bunches using the 1.7 GHz Schottky system installed in the Tevatron.  **(FNAL, FY’06)**
- Design of a traveling wave pick-up structure optimized for the LHC beam and machine parameters. CERN pays for the manufacturing **.(FNAL, FY’06)**
- Design and assembly of four sets of front-end electronics (plus spares) for the pick-ups. This includes all amplifiers, filters, gating and down-mixing circuitry between the pick-ups and the digitizer. CERN provides the gate generator (TTL level), a 40 MHz RF source and the DAQ hardware **(FNAL, FY’06-07)**
- A study of the performance of the DAB board (with 24 bit, 96 kHz ADC mezzanine card) for 1.7 GHz Schottky signals in RHIC and/or Tevatron. **(BNL/FNAL, FY’06)**
- Porting the Fermilab Schottky analysis software to the CERN control system framework. CERN provides the generic controls communications software and the platform for running the code. **(FNAL, FY’06-07)**
- Hardware commissioning with US personnel on location at CERN. This includes transferring expertise to a local CERN designee. **(FNAL, FY’07-08)**
- Beam studies on location at CERN to attempt to e.g. passively measure tunes during ramp and squeeze (this has been difficult in the Tevatron, but may be possible in the LHC due to the much slower ramping). Also attempt emittance and chromaticity measurement**. (FNAL, FY’07-08)**
- Capability to continuously measure the average LHC tune during stores without external excitation. This has shown very useful in the Tevatron, and allows for slow tune feedback during stores, if required. (**FY’07-08)**
- Capability to measure tune of user-selected single bunches in the LHC. Studies of e.g. electron cloud effects and beam-beam detuning of single bunches (PACMAN effect), which are expected to be critical to the LHC performance, will rely on this capability. **(FY’07-08)**

**From Port Jeff collaboration meeting**

- LARP Collaboration Meeting,  October 5-6, 2005

## People

- FNAL
- R.Pasquinelli, P.Lebrun , D.Sun, D.Tinsley, A.Jansson
- BNL
- P.Cameron, P.Oddo
- CERN
- _F.Caspers_, R.Jones

**From Port Jeff collaboration meeting**

- LARP Collaboration Meeting,  October 5-6, 2005